CH1786A Family of Ultra Small 2400bps Modems INTRODUCTION The CH1786A represents the next generation of full function, FCC Part 68 approved 2400bps modems in the CH1786 Family. These modems provide a fast, easy and flexible way to integrate a modem into any OEM product while utilizing the minimum amount of PCB space (1.01"x 1.27"x 0.52"). The CH1786A family only requires two external interfaces: a ITU-T V.24 serial interface that can be routed directly to a UART, and a Tip and Ring interface which goes directly to an RJ-11 jack for the PSTN line connection. The CH1786A can be controlled with industry standard AT commands and, hence, is compatible with available industry communication software. DTE speed conversion allows commands and data to be sent at rates that differ from the modem connection speed. In most cases, the CH1786A can be used interchangeably with the CH1786. See Attachment I for equivalency comparisons and differences by product. * * * * * * * * * * * * * UL 1950 Edition 3 and CSA C22.2 950 Listed. UL File Number: E251266. AT Command structure with extensions. 1500 VAC RMS isolation barrier minimum, 2122V peak surge protection minimum. Error Correction. Fast Connect (V.22). Single 5 volt operation. Caller ID (optional). Low power operation with automatic reduced power standby mode. Zero Power (optional). Automatic adaptive and fixed compromise equalization. Size: 1.01"x 1.27"x 0.52" (nominal). NVRAM allows storage of custom configurations and telephone numbers. All CH1786A modems support asynchronous operation at 2400bps, 1200bps, and 300bps to both Bell and ITU-T standards. The CH1786A also supports Fast Connect and LAPM/MNP Error Correction. The resident PSTN line interface, or Data Access Arrangement (DAA), while being FCC approved, is also Industry Canada CS-03 Part I Registered. Further, the CH1786A can be approved in other countries that require 1500VAC RMS isolation requirements per UL 1950 Edition 3. The CH1786A family of modems operate off a single 5-volt supply. The low power operation and automatic standby mode make these modems ideally suited for portable equipment. In addition, their small physical size affords maximum flexibility in equipment design. CH1786A comes with FCC Part 68 approval and is shipped from the factory with an FCC Part 68 label indicating the registration number and ringer equivalent. This label should be prominently displayed on the end product. FEATURES * Supports Standards ITU-T V.22bis, V.22, Bell 212, and Bell 103. * FCC Part 68 approved: US:B46MM07BCHXXXXAYY * Industry Canada CS-03 Part I Registered: IC:176A-CHXXXXAY 2006 Cermetek Microelectronics, Inc. Page 1 Figure 1. Functional Block Diagram of CH1786A. DESCRIPTION OF FUNCTIONAL BLOCKS AND DISCUSSION OF BASIC OPERATIONS Figure 1 contains a functional block drawing of the CH1786A. The CH1786A is a highly integrated, fullfunction modem, comprised of a modulator/ demodulator, controller, NVRAM and an FCC Part 68 approved and UL 1950 Edition 3/CSA C22.2 950 listed PSTN line interface. Modulation/Demodulation and Modem Controller. These functions are provided by a monolithic modem integrated circuit. This IC has built-in facilities to accommodate integrated AT command control and contains the necessary resident interfaces for general communication and routing to the DAA. Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems Telephone Line Interface or DAA. The CH1786A SUPPORT FEATURES AT Command Set. A 50-character command line is supported. The command line starts with AT and may contain standard or enhanced commands. The commands are compatible with EIA Document TR302.2/88-08006. Serial Host Interface. The serial interface is a V.24 (EIA-232) compatible interface. Ten Bits total: 1 start bit, 1 stop bit, and eight data bits which can be either eight bits with no parity or seven odd or even with parity. The start bit is LOW going. RXD and TXD data is non-inverted. See pin description in Table 2. Figure 2. Voice/ Data Port Control family of modems is designed to meet 1500VAC RMS isolation and provide 2122V peak surge protection. Consequently, the CH1786A satisfies U.S. FCC Part 68 and Industry Canada CS-03 Part I requirements, and will meet other international approval agency requirements that specify these levels of isolation. With the exception of the U.S., most countries (including Canada) require submission of the final product or system containing the CH1786A to the appropriate governing regulatory agency for approval. Typically this is accomplished by submitting the final end product to an independent test house or consultant for evaluation. The test house or consultant then forwards the test results and applicable documents to the regulatory agency. Call Cermetek for a list of suggested consultants. Non-Volatile RAM (NVRAM). The NVRAM present on the CH1786A is sufficient to store up to two user customized modem profile configurations. The AT&Wn command will store the active modem configuration in the selected NVRAM profile by specifying either an n of 0 or 1. The CH1786A is delivered with Factory Default setup parameter values pre-stored in NVRAM profile 0. The AT&Yn command selects the modem configurations to be automatically recalled and made active upon a reset or power up. The ATZn command immediately recalls and activates a stored profile configuration. Refer to Tables 4, 5 and 6 for storable S-Registers and available commands. The NVRAM can save up to four telephone numbers with up to 31 digits or modifiers in each telephone number. The AT&Zn=s command will store s, the telephone number dial string. The individual NVRAM telephone number storage locations are selected by specifying an n of 0, 1, 2, or 3. The ATDTS=n command will cause the modem to dial the stored telephone number in location n. 2006 Cermetek Microelectronics, Inc. Page 2 Speaker Interface. The SPK output reflects the receiver analog input and provides a signal that can be used to monitor call progress. The SPK signal can drive a 300 load directly. Typically, the SPK signal is input into an audio power amplifier and the amplifier, in turn, drives the speaker coil. The speaker is activated with the ATMn command. The speaker volume is adjusted using the ATLn command, where n is 0, 1, 2, or 3. Increasing numbers correspond to higher volume. Figure 5 indicates one method of driving an external 8 speaker. Phone Control. Cermetek's CH1786A contains a pin called Voice or Data (V/D). The V/D pin toggles high when the modem goes off hook. This pin can be used to activate a relay which can switch a telephone on or off the Tip and Ring incoming PSTN lines. This feature allows any telephone associated with the CH1786A to be disconnected when a data call is in progress, thereby preventing the data from being disturbed by an inadvertent telephone pick-up. See Figure 2. Speed and Parity Selection. Prior to call initiation, the host controller trains the modem to the host speed (2400, 1200 or 300bps) and parity (odd, even, mark, space, or none) via a host-initiated training sequence. This training also sets the speed of the data for originate calls. The CH1786A will automatically adjust to the originator's speed when answering calls. The CH1786A matches the host's parity when it returns status messages to the host. During a data connection, however, the modem passes parity through without interpretation or alteration. Sleep Mode. To minimize power consumption, the CH1786A includes a power down feature called Sleep Mode. When activated, the CH1786A will automatically enter Sleep Mode after 1 to 255 seconds of inactivity. The inactivity delay is selected using the ATS24 command and defaults to 0 which will disable this feature. The CH1786A returns to normal operation when a ring signal is received or upon an input low signal on the TXD pin. A SLEEP output signal is available to control power to external devices. Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems In Figure 5, a FET controlled by the SLEEP signal turns off the external speaker amplifier when the CH1786A enters Sleep Mode. In Sleep Mode, power is reduced to about 1/3 of normal operating power. Zero Power Mode. The "P" versions of the CH1786A Family supports Zero Power Mode operation. If an application calls for zero power during standby periods, this feature allows the power to the CH1786A to be switched off using external circuitry and then reapplied when the CH1786A's RI pin becomes active. The CH1786A can thus be powered down to zero. Referring to Figure 3, the controller activates the relay switch, supplying power (+5V) to the CH1786A. In this configuration, the ring signal is used to "wake up" the CH1786A when the CH1786A is in the zero power state. web site located at Answer Tone. A ITU-T (2100 Hz) or Bell (2225Hz) answer tone is generated depending on the selected configuration. Refer to "AT Commands and SRegisters" for a more detailed discussion. Data Encoding. The data encoding conforms to ITUT recommendations V.22bis or V.22, or Bell212A, or 103, depending on the selected configuration. Refer to "AT Commands and S-Register" for a more detailed discussion. Line Equalization. Transmitter and receiver digital filters compensate for delay and amplitude distortion during operation on nominal phone lines. In addition, automatic adaptive equalization in the receiver minimizes the effects of inter symbol interference. Transmission Speed. In normal operation, the originating modem initiates the call and attempts to connect to the answering modem at a speed established by the originating modem's controller prior to call initiation. This is referred to as the Initial Trained Rate. Upon receiving the call, the answering modem will attempt to connect to the originating modem at its Initial Trained Rate. If these two rates are identical, the connection is made. If the speeds differ, the answering modem must adjust its rate or terminate the call. Table 1 indicates the connection rate when the calling modem's Initial Trained Rate and answering modem's Trained Rate are different. CH1786A-P Error Correction. The CH1786A supports LAPM and MNP error correction. Error correction is enabled via the \Nn command. Enabling error correction overrides &Qn and sets S36 and S48 values. Refer to Cermetek, "AT Commands and S-Registers", for a more detailed discussion. Figure 3. Zero Power Operation. As indicated in Figure 2, the user connects an external pull-up resistor (Cermetek recommends 30k ohms) to an active 5V source thereby providing a small current to the CH1786A through the RI pin when the CH1786A is powered down (i.e., no power applied to the VCC pin). An internal blocking diode provides supply isolation. The pins of the CH1786A will be in an undefined state when powered is switched off. This must be taken into consideration to assure that no unwanted signals are presented to the CH1786A during power down. Guard Tone. A guard tone of 550 Hz or 1800 Hz can be generated at 6 dB or 9 dB below the transmit level, respectively, by using the &Gn command. For a more detailed discussion, refer to Cermetek Document 6130001, "AT Commands and S-Registers", which can be 2006 Cermetek Microelectronics, Inc. found on the Cermetek http://www.cermetek.com. Page 3 Table 1. Connection Rates. Connection Rate Resulting When Calling Modem Initial Answering Modem Rate Is: Initial Trained Rate 300 1200 2400 300 300 1200 1200 1200 300 1200 1200 2400 300 1200 2400 NOTE A 2400-baud connection rate will only result if both modems are initially set at 2400 baud. Ring Indicator (RI). The RI pin follows the frequency of the ring signal and toggles low when the CH1786A detects an incoming call. The ring signal is typically 20 to 30 Hz and is on for 2 seconds and off for 4 seconds. Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems Although not TTL compliant, the RI pin can, nonetheless, be utilized to activate external circuitry including the external RST pin. +MS Command. The user may override the automatic data rate function of the HS modems. This is accomplished by executing the +MS command. This command allows the user to specify the desired data modulation protocol. Further, the +MS command may be used to force a desired data rate and/or restrict the allowed data rate. The supported modulation schemes are listed above. The following examples modulation scheme: Enter: Result: establish the Typically, voice communication would precede data communications. For this case, the following commands should be used to configure the CH1786A (Refer to Figure 4): Enter: ATS0=0<CR> Result: OK Disables auto-answer Enter: ATS7=255<CR> Result: OK Disables data-carrier time out V.22bis Enter: ATS10=255<CR> Disables lost-carrier time Result: OK out AT+MS=V22B OK This is identical to the following explicit +MS command: Enter: Result: schematic indicating one possible configuration for voice/ tone utilization. AT+MS=V22B,0,300,1200,300,1200 OK NOTE The minimum transmission rate is not stored and will default to 300bps upon execution of reset or upon power up. The following implementation applications. Refer to, "AT Commands and S-Registers", for a more detailed discussion of the +MS command. Power Supply. The CH1786A modem module is a complex set of sub-systems. During the course of normal operation the CH1786A decodes analog signals from the telephone line that are in the millivolt range. Steps must be taken by the user to guarantee that power supply noise on all supply lines, including ground, does not exceed 50 mV peak to peak. Any frequency between 20 kHz and 150 kHz must be less than 500 micro volts peak. If necessary, use dedicated power and ground planes. Failure to provide such operating conditions could cause the CH1786A to malfunction or to function erratically. The CH1786A requires a single +5V 5% supply. It is recommended that by-pass capacitors be placed on the power supply as close to the modem's supply input as practical. It's recommended a 10 F Tantalum capacitor in parallel with a 0.01 F ceramic capacitor be used. Voice/DTMF Tone Injection Port. The CH1786A provides two pins to allow the user to share the telephone line interface associated with the modem for voice and DTMF applications. Figure 4 contains a 2006 Cermetek Microelectronics, Inc. WARNING The CH1786A has been FCC Part 68 and Industry Canada CS-03 Part I approved as a data modem only. Utilization of the Voice/DTMF Tone Port requires further registration. FCC and Industry Canada will require that the system, including the CH1786A and the handset or DTMF transceiver, adhere to Part 68 and CS-03 Part I rules. Page 4 command sequences illustrate of common Voice/Tone Port 1. To answer a voice call. (a) Enter: ATH1<CR> Result: OK (b) Drive V.INJ. HIGH to activate relay. (c) Begin voice conversation. 2. To switch to data mode. (a) Drive V.INJ. LOW (b) At the originate modem: Enter: ATX1<CR> Result: OK 3. To disconnect (hang-up) a voice call or a data call. (a) Enter: ATH<CR> Result: OK 4. Place a call to 1234567 using the CH1786A's DTMF tone generator, then use VOICE mode for voice communications. Note that the CO command disables carrier generation. (a) Enter: ATDT1234567;C0<CR> Result: OK (b) Drive V.INJ. HIGH MODEM CONTROL The CH1786A modem may be controlled by sending serial ASCII command sequences. The commands Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems are sent to the modem serially on the TXD pin. After execution of a received command, the modem returns a serial status message that can be read on pin RXD. This message indicates command completion status. Refer to Table 3 for a complete list of status messages. Training the Modem. Each modem must be trained to match its host's speed and parity so that it is able to recognize serial asynchronous commands sent to it by the host's is UART. The host must retrain the modem each time a reset pulse is applied on RST or after a RESET serial command has been issued. Modem Training Command Sequence. The CH1786A is trained by sending it the following sequence: Enter: AT<CR> Result: OK Where: A and T may be either upper or lower case but must be the same case. <CR> represents carriage return The AT sequence is referred to as an attention sequence. The CH1786A will respond with one of the following status messages, depending on whether it is optioned for Terse (abbreviated) or Verbose (English) status messages. Figure 4. Voice/Tone Injection. IMPORTANT NOTE Although every effort has been made to design the CH1786A products to be fully and completely compatible with the existing CH1786 family, there are some minor differences. Refer to Table 14 for equivalency information and refer to Attachment I for a summary of product differences. INITIALIZING THE MODEM Before commands may be sent to the CH1786A, the CH1786A must be initialized. Initialization is a two step activity consisting of: 1. Hard Reset. This is accomplished by applying a hardware reset pulse to pin RST or by switching the power off and then back on. 2. Initial modem training. The CH1786A must be trained to the host's speed and parity (odd, even, mark, space or none). These activities are briefly described below. Reset. Upon applying power to the CH1786A, the CH1786A automatically generates an internal reset pulse. The user may also reset the modem externally by applying a high-going reset pulse to the RST pin for at least 10ms after the +5V power supply has stabilized. Delay sending commands to CH1786A for 200ms after reset has been initiated to allow the CH1786A time to properly reconfigure. 2006 Cermetek Microelectronics, Inc. Page 5 Result: 0<CR> (Terse) or Result: <CR><LF>OK<CR><LF> (Verbose) Where: <CR> represents carriage return (ASCII 13 or HEX 0D). <LF> represents line feed (ASCII 10 or HEX 0A). After responding with an OK, the CH1786A is in idle mode and is ready to accept additional commands. An alternate attention sequence A/ may be sent which behaves much like the AT sequence except that it causes the previously entered command specified with an AT prefix to be executed. When given, both the AT and A/ must be in upper case ASCII. No carriage return is needed for the A/ command. THE COMMAND FORMAT Typical commands consist of three elements: the attention sequence, the commands themselves, and a terminating carriage return. AT[commands]<CR>. Where: AT represents attention sequence. [Commands] represents command strings. <CR> represents carriage return (ASCII 13 or HEX 0D). When entering commands to the modem, the backspace character-control-H (ASCII 8 or HEX 08) may be used to edit mistakes. AT and A/ may not be edited. Multiple commands may be placed in the command line. A command line may be as long as 40 characters, excluding the letters AT. By way of example, the command below instructs the CH1786A Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems to configure itself to not echo characters when in command mode E0 and then put itself in answer mode A. Enter: ATE0A<CR> Result: OK AT COMMAND APPLICATIONS AT Command Set. The available command set is divided into four types of commands: dial modifiers, basic commands, ampersand and percent commands. Refer to the complete list in Table 5. Example: Dial number. Enter: ATD1234567<CR> Result: OK AT Command Data Rate. With the serial interface, the rate is speed sensed for parity and format. THE STATUS MESSAGES The CH1786A responds with a status message after each command is executed. This status message may either be a numeric code (Terse Result Code) followed by a carriage return; or a carriage return and line feed with a message in English (Verbose Result Code) followed by a carriage return and line feed. Various status code subsets are enabled with the Xn command. Where n=0, 1, 2, 3, 4 establishes the result codes allowed to be sent from the CH1786A to the DTE. NOTE The CH1786A is factory set to X4, which allows all result codes. In response to this command, the CH1786A dials the telephone number "123-4567" and then waits for a carrier from the distant modem. If no carrier is detected within a given time (the default time is 30 seconds), the CH1786A automatically releases the line and sends a NO CARRIER result code. If a carrier is detected, the CH1786A gives a CONNECT result code and goes on-line, permitting communication with the distant modem. The Dial Command may also be issued without a telephone number. ATD causes the modem to pick up the telephone line without dialing a number. Pause During Dialing. When placing a call from an office with a telephone connected to a PBX, it may be necessary to dial an access code (usually the digit 9) to get an outside line. Inserting a comma in the telephone number instructs the modem to pause for a specific length of time. The factory set default pause time is 2 seconds. Example: Dial 9,pause, dial number. Enter: ATDT9,1234567<CR> Result: OK MODEM STATES The CH1786A can be in either command mode or data mode. When the modem is idle, it is in command mode by default and will recognize commands. When data transmission is in progress, the CH1786A is in the data mode state and will not recognize commands. To force the CH1786A to recognize commands, the host must send an escape sequence to the CH1786A forcing it out of data mode and into command mode. The escape sequence consists of a "guard time" (a period where no characters are sent to the modem), followed by 3 escape characters, followed by another guard time. The guard time is set by register S12. The escape character code is set in register S2. At power-up, the guard time is set to 1 second minimum, and the escape character is set as "+." There is no minimum delay between characters but the maximum delay is set by register S12. The CH1786A will stay off-hook with its carrier on after the escape sequence is received. It will return an OK status message when it is ready to accept commands. The CH1786A may be put into data mode by issuing the command ATO<CR>. 2006 Cermetek Microelectronics, Inc. Dialing A Phone Number. The Dial command takes the form Dn, where n is a string of characters. In the simplest form, n will be only the digits of the phone number to be dialed. Page 6 Multiple commas may be used to generate integer multiples of the specified delay time. Originate a Call in Answer Mode. The D command forces the modem into originate mode. To call an originate-only modem, dial the number and set the modem to answer mode via the R command (reverse originate). This is done by including an R at the end of the telephone number. Example: Change modem from original-only to answer mode. Enter: ATDT1234567R<CR> Result: OK Multiple commas may be used to generate integer multiples of the specified delay time. Redial Last Number. The repeat command is a convenient way to execute the previously entered command line. Example: Use A/, the repeat command, to redial the last telephone number dialed. Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. Enter: Result: CH1786A Family of Ultra Small 2400bps Modems (telephone presented. A/ ATDT1234567R<CR> Previous command OK line executed 2 Return to Command State. Use ; to return to command mode offer dialing. Example: Touch-tone dial 9, pause, dial number, return to Command. Enter: ATDT9,1234567;<CR> Result: OK V.22 Fast Connect. The CH1786A supports nonstandard V.22 fast connect protocols. This feature reduces the connect time to 3-4 seconds. However, to utilize the fast connect protocol, this protocol must be supported by both modems. Further, the DCE speed must be set to 1200 baud (i.e., V.22). To setup the CH1786A to connect utilizing Fast Connect, execute the following commands: Enter: $F2<CR> Result: OK This forces the CH1786A to communicate using the V.22 protocol and to attempt to connect using Fast Connect. If Fast Connect is not supported by the other modem, the CH1786A will connect using the standard V.22 protocol. Caller ID (CID). The "C" versions of the CH1786A Family supports Caller ID. The +VCID command controls reporting and presentation of the data provided by the PSTN Caller ID services. Data is presented to the DTE between the first and the second ring indication. This command affects the data format for incoming calls as the call is being received. AT+VCID=n&W0&W1<CR> OK<CR><LF> IMPORTANT NOTE The &W0 (or &W1) command, as appropriate per the specification of &Y0 (or &Y1), must be executed before the +VCID command will be implemented by the CH1786A. data is Enables Caller ID with unformatted presentation to the DTE. The data is presented in a continuous string. HEXADECIMAL data is presented. Refer to Application Note # 174, Caller ID Feature For CH1786A, CH179XA and CH2056A Modems, for additional information and examples. The AT+VRID command affects the format of the data provided by the PSTN Caller ID services for the last received call. The DTE is presented this data once every time the +VRID command is executed. Enter: AT+VRID=n<CR> Result: Data Stream from most recent call 0 Reports Caller ID with formatted presentation to the DTE. The data is presented the data items in a <Parameter Description> <Value> pair format. The expected pairs are: date, time, name, and caller code (telephone number). 1 Reports Caller ID with presentation to the DTE. unformatted Refer to Application Note # 174, Caller ID Feature For CH1786A, CH179XA and CH2056A Modems, for additional information and examples. IMPORTANT NOTE Caller ID (CID) requires that the PSTN service provider supply the required data. The Caller ID feature will report the NULL string if the CID service is not activated by the PSTN service provider. Automatic Answering. The S0 register controls the number of rings that must occur before the CH1786A answers a incoming call. The register may range in value from 0 to 255. Where n is a decimal number corresponding to the selected option as described below. To set the CH1786A to not answer any incoming calls, executed the following command: Enter: ATS0=0<CR> Response OK 0 Disable Caller ID reporting. (Default.) 1 Enables Caller ID with formatted presentation to the DTE. The data presented is in a <Parameter Description> <Value> pair format. The expected pairs are: date, time, name, and caller code 2006 Cermetek Microelectronics, Inc. ASCII Where n is a decimal number corresponding to the selected option as described below. Enter: AT+MS=V22,0,300,1200,300,1200<CR> Result: OK Enter: Result: number). Page 7 When S0 is set to 0, the modem will not auto-answer. To set the CH1786A to answer after 3 rings, execute the following command: Enter: ATS0=3<CR> Response OK Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems Figure 5. CH1786A block diagram illustrating typical feature implementations: V/D control, RJ-11 connection, speaker for call progress monitoring, serial port connection, external reset, +5V and GND. 2006 Cermetek Microelectronics, Inc. Page 8 Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems Table 2. CH1786A Pin Descriptions FUNCTION PIN NAME TYPE 1 RING I/O RING. Directly connects to the telephone line's Ring lead through a user supplied RJ-11C jack. 2 TIP I/O TIP. Directly connects to the telephone line's Tip lead through a user supplied RJ11C jack. 3 RXA O ANALOG VOICE INJECTED. Receive Signal. Let float if not used. 4 TXA I ANALOG VOICE INJECTED. Transmit Signal. Let float if not used 5 SPK O SPEAKER. Audio output for speaker. See speaker control schematic in Figure 5. 6 NC - No connection. 7 NC - No connection. 8 SLEEP O SLEEP. Active LOW. A LOW indicates CH1786A is in low power idle mode. Used to control power to other devices. See Figure 5. Register S24 is the sleep timer register. When the CH1786A is inactive for a period of time specified by S24, the CH1786A will power down by about 1/3 of its normal operating power. During power down, all I/O lines become undefined. Default is (ATS24=0) disabled. 9 NC - No connection. 10 TXD I TRANSMIT DATA. Active Low. Serial Transmit data input. Marking or a binary 1 condition is transmitted when a HIGH is asserted. 11 RXD O RECEIVE DATA. Active Low. Serial Receive data output. Received marking or binary 1 condition is indicated by HIGH. 12 V/D O VOICE/DATA. Used to switch between telephone and modem line use. In a typical application, V/D active HIGH opens the normally closed voice injection relay and disconnects the handset from the telephone line. HIGH indicates the CH1786A is off-hook and online. Therefore, this pin also reflects the state of the off-hook relay of the CH1786A. See Figure 2. Let float if not used. 13 DTR I DATA TERMINAL READY. Active LOW. Switching off DTR can either return modem to command state, disconnect phone call, or reset modem. DTR should be set LOW when not used. 14 DSR O DATA SET READY. Active LOW. LOW indicates handshaking with a remote modem is in progress, and/ or the data carrier of a remote modem has been detected. 15 RI O RING INDICATION. This signal follows the frequency of the ringing signal and is normally about 20 to 40 Hz for 2 seconds on with 4 seconds off. This pin is also used for Zero Power option. See Figure 3. 16 CTS O CLEAR-TO SEND. Active LOW. Used for hardware Flow Control of data. 17 DCD O DATA CARRIER DETECT. Active LOW. LOW indicates a data carrier from a remote modem is detected. Must be enabled using the &C1 command. 18 NC - No Connection. 19 VCC - POWER SUPPLY. 5 volts + 5% 20 GND - GROUND. Note: Noise should be less than 50mV peak to peak. 21 RST I RESET. Active HIGH. This input must be asserted HIGH for at least 10 ms to reset the modem. RESET is then returned LOW for normal operation. If no system reset is available, let this pin float. Input impedance of driving circuit should be <10K. 22 NC I No Connection. 2006 Cermetek Microelectronics, Inc. Page 9 Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems Table 3. S-Register Summary. Register S0 S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12 S13 S14 S15 S16 S17 S19 S20 S21 S22 S23 S24 S25 S26 S27 S28 S29 S30 S31 S36 S37 S38 S39 S40 S41 S43-S45 S46 S48 S82 S86 S91 S92 S95 S210 NOTES: Function Rings to Auto-Answer Ring Counter Escape Character Carriage Return Character Line Feed Character Backspace Character Wait Time before Dial Tone or Blind Dialing Wait Time for Carrier, Silence or Dial Tone Pause Time for Dial Delay Modifier Carrier Detect Response Time Carrier Loss Disconnect Delay DTMF Tone Duration Escape Prompt Delay Reserved General Bit Mapped Options Status Reserved Test Mode Bit Mapped Options Status (&T) POS Option Reserved Reserved V.24/General Bit Mapped Options Status Speaker/Results Bit Mapped Options Status General Bit Mapped Options Status Sleep Inactivity Timer Delay to DTR off RTS-to-CTS Delay General Bit Mapped Options Status General Bit Mapped Options Status Flash Dial Modifier Disconnect Inactivity Timer General Bit Mapped Options Status LAPM Failure Control Line Connection Speed Delay Before Forced Hang-up Flow Control Bit Mapped Options Status General Bit Mapped Options Status General Bit Mapped Options Status Reserved Data Compression Control V.42 Negotiation Control LAPM Break Control Call Failure Reason Code PSTN Transmit Attenuation Level FAX Transmit Attenuation Level Result Code Messages Control V.34 Symbol Rate Range 0-255 0-255 0-255 0-127 0-127 0-255 2-255 1-255 2-255 1-255 1-255 50-255 0-255 0-255 0-255 0-255 0-255 0-255 0-255 0-26 0-15 0-15 0-255 Units rings rings ASCII ASCII ASCII ASCII s s s 0.1s 0.1s 0.001s 0.02s s 0.01s 0.01s 0.01s 10ms s dBm dBm - Saved * * * * * * * * * * * * * * * Firmware Defaults 000 000 043 013 010 008 002 050 002 006 014 085 050 000 146 (92H) 000 000 000 000 000 052 (34H) 117 (75H) 000 000 005 001 073 (49H) 000 070 000 192 (C0H) 007 000 020 003 104 (68H) 195 (C3H) 138 007 000 021 011 011 000 141 (8CH) Factory Defaults 001 000 043 013 010 008 002 050 002 006 014 085 050 000 146 (92H) 000 000 000 000 000 100 (74H) 117 (75H) 000 000 005 001 074 (4AH) 000 070 000 192 (C0H) 007 000 020 003 104 (68H) 192 (C0H) 136 007 000 021 011 011 000 141 (8CH) 1. Parameters indicated with a (*) in the Saved column may be stored in User Profile n=0, 1 by executing the appropriate &Wn command. 2. A stored Profile is a subset of allowed parameters and is comprised of those parameters displayed with the &V command. 3. Factory Default values that are different from the Firmware Default values are highlighted in BOLD. 4. Restore Factory Default values using Zn command. 5. Restore Firmware Default values using &Fn command 2006 Cermetek Microelectronics, Inc. Page 10 Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. Table 4. Extended Result Code Summary. Result Code Form n is ATXn Command Terse Verbose or Long 0 1 2 3 or Short +F4 +FCERROR X X X X 0 OK X X X X 1 CONNECT X X X X 2 RING X X X X 3 NO CARRIER X X X X 4 ERROR X X X X 5 CONNECT 1200 1 X X X 6 NO DIAL TONE 3 3 X X 7 BUSY 3 3 3 X 8 NO ANSWER X X X X 9 CONNECT 0600 1 X X X 10 CONNECT 2400 1 X X X 11 CONNECT 4800 1 X X X 12 CONNECT 9600 1 X X X 13 CONNECT 7200 1 X X X 14 CONNECT 12000 1 X X X 15 CONNECT 14400 1 X X X 16 CONNECT 19200 1 X X X 17 CONNECT 38400 1 X X X 18 CONNECT 57600 1 X X X 19 CONNECT 115200 1 X X X 20 CONNECT 230400 X X X X 22 CONNECT 1 X X X 75TX/1200RX 23 CONNECT 1 X X X 1200TX/75RX 24 DELAYED 4 4 4 4 25 MESSAGE-WAITING X X X X 32 BLACKLISTED 4 4 4 4 33 FAX X X X X 35 DATA X X X X 39 +MRR: 75 X X X X 40 +MRR: 300 X X X X 42 +MRR: 600 X X X X 44 +MRR: 1200/75 X X X X 45 +MRR: 75/1200 X X X X 46 +MRR: 1200 X X X X 47 +MRR: 2400 X X X X 48 +MRR: 4800 X X X X 49 +MRR: 7200 X X X X 50 +MRR: 9600 X X X X 51 +MRR: 12000 X X X X 52 +MRR: 14400 X X X X 66 +DR: ALT X X X X 67 +DR: V42B X X X X 68 +DR: V44 X X X X 69 +DR: None X X X X 70 +ER: NONE X X X X 77 +ER: LAPM X X X X CH1786A Family of Ultra Small 2400bps Modems Table 4. Extended Result (Continuation). Result Code Form 4 Terse or Short 80 81 83 85 X X X X X X X X X X X X X X X X X X X X X X X 86 87 91 130 134 135 136 137 138 139 139 140 141 210 211 212 213 214 X X X X X X X X X X X X X X X X X X X X X X X X Verbose or Long +ER: ALT +ER: ALT-CELLULAR LINE IN USE OFF-HOOK INTRUSION LINE REVERSAL DETECTED NO LINE CONNECT 31200 +ILRR +MCR: B103 +MCR: B212 +MCR: V21 +MCR: V22 +MCR: V22B +MCR: V23 +MCR: V23C +MCR: V32 +MCR: V32B +MRR: 25333 +MRR: 26667 +MRR: 25333 +MRR: 22666 DIGITAL LINE DETECTED Code Summary n is ATXn Command 0 1 2 3 4 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X IMPORTANT NOTE An "X" in a column indicates that the message (either the long form if verbose, or the value only for short form) will be generated when that particular value of "n" (shown at the top of the column) has been selected by the use of ATXn. A numeral indicates which less explicit message (verbose or short form) will be output for that X option. The Serial Interface Lines. The CH1786A supports a full EIA-232E/V.24 serial interface. Signal levels are TTL rather than EIA-232E level compatible, which allows direct connection of the CH1786A to the host UART without the need for level translation circuitry. See Table 2 for a complete pin description. The CH1786A is controlled by sending it serial commands over TXD and it's status determined by monitoring the serial status messages returned on RXD. DTR is optionally used to reset, terminate calls or return CH1786A to command mode. All other serial interface lines may be utilized for the convenience of a particular application but are not 2006 Cermetek Microelectronics, Inc. Page 11 Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems Table 5. AT Command Summary. Command Function A/ Re-execute command A Go off-hook and attempt to answer call B0 Select CCITT connection at 300 or 1200bps B1 Sect Bell connection at 300 or 1200bps Dn Dial modifier where n is one or more of the following: P Pulse Dial T Touch Tone Dial W Wait for Dial Tone ; Return to Command State @ Wait for Quiet Answer Command ! Flash Hook , Pause 0-9/ABCD Dial Digits/Characters & wait for credit card dial tone ^ Toggles calling tone L Redial last number *,# Star digit - tone dialing S=n Dial the number and store in Directory, n= 0 to 3 E0 Disable command echo E1 Enable command echo H, H0 Initiate a hang-up sequence H1 If on-hook, go off-hook and enter command mode L0 Set low speaker volume L1 Set low speaker volume L2 Set medium speaker volume L3 Set high speaker volume M0 Speaker off M1 Speaker on during hand shaking and speaker off while receiving carrier M2 Speaker on during hand shaking and while receiving carrier M3 Speaker off during dialing and receiving carrier and speaker on during answering O0 Go on-line O1 Go on-line and initiate a retrain sequence Sn Select S Register n Sn=m Write value m to S Register n Sn? Read the value of S Register n ? Returns Last addressed S Register value V0 Short Form Result Code Option V1 Long Form Result Code Option X1, X2, Result Code Reporting Options X3, X4 +++ Escape Code Sequence Z0, Z1 The modem performs soft reset. Restore stored profile 0 or 1 after reset &C0 Force DCD active regardless of the carrier state &C1 DCD to follow the carrier state 2006 Cermetek Microelectronics, Inc. Page 12 Table 5. AT Command Summary (Continuation). Command Function &D0 Modem ignores DTR &D1 Modem assumes command state &D2 Modem hangs up, assumes command state and disables autoanswer &D3 Modem assumes initialization state &F0 Restore Factory configuration 0 &F1 Restore Factory configuration 1 &G0, 1, 2 Guard Tone Options &K0 Disable DTE/DCE flow control &K1,2 Not Supported &K3 Enable RTS/CTS DTE/DCE flow control &K4 Enable XON/XOFF DTE/DCE flow control &K5 Enable transparent XON/XOFF flow control &P0, 1, 2, 3 Make to Break Ratio Options &Q0 Select direct asynchronous mode &Q1,2,3,4 Not Supported &Q5 Modem negotiates an error corrected link &R0 CTS tracks RTS &R1 CTS always on &S0 DSR always on &S1 DSR active after answer tone detected and inactive after loss of carrier &T0 Terminate Loopback Test &T1 Initiate Loopback Test \Bn Send break of n x 100 msec (n=0 to 9) \N0 Select normal speed buffered mode \N1 Select direct mode \N2 Select reliable mode \N3 Select auto reliable mode \N4 Force LAPM mode \N5 Force MNP mode \V0 Connect messages are controlled by the command settings X, W, and S95 \V1 Connect messages are displayed in the single line format MODULATION COMMANDS +MS Select modulation +MCR=n Carrier protocol n reporting +MR=n Select extended Modulation Reporting of +MCR and +MRR to DTE +MRR=m, n Report Transmit m and Receive n DCE rates to DTE CALLER ID COMMANDS +VCID Select data presentation format n (02) for incoming calls. Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems Fax Modes. The CH1786A Product Family supports Send and Receive FAX. The modes and rates are determined by the AT+F commands. Refer to Table 6A. Table 5. AT Command Summary (Continuation). Command Function +VRID Select data presentation format n (01) for most recently received incoming call. ERROR CORRECTING COMMANDS FAX modem processing is explicitly defined in ITUTV.29, ITU-TV.27, ITU-TV.21 and ITU-T V.17 recommendations. All modulation, wave-form spectrum, and data processing functions conform to the appropriate specifications. %C0 %C1 %C2 %C3 Disable data compression Enable MNP 5 data compression Enable V.42bis data compression Enable both V.42bis and MNP 5 compression STORED PROFILE COMMANDS &V Display current configuration &W0 Store the active profile in NVRAM profile 0 &W1 Store the active profile in NVRAM profile 1 &Y0 Recall stored profile 0 upon power up &Y1 Recall stored profile 1 upon power up &Zn=x Store dial string x (31 digits max) to location n (0-3) MNP10 COMMANDS -K0 Disable MNP 10 extended services -K1 Disable MNP 10 extended services -K2 Disable MNP 10 extended services FAX COMMANDS +FCLASS=n Service Class +F<cmd>? Report active configuration for specified command cmd +F<cmd>=? Report capabilitied for specified command cmd +FAA=n Data/Fax Auto Answer +FLO Flow Control +FMI? Report Manufacturer ID +FMM? Report Model ID +FMR? Report Revisions ID +FRM=n Receive Data with n protocol +FTM=n Transmit Data with n protocol +FRH=n Receive Data with HDLC Framing with n protocol +FTH=n Transmit Data with HDLC Framing with n protocol +FTS=n Stop Transmission and Wait FAST CONNECT COMMANDS $F0 Normal connection (Default) $F1,3,4 Not Supported $F2 V.22 Fast Connect IDENTIFICATION COMMANDS I0 Reports product code I3 Reports firmware Identification code PHONE LINE CONNECTION GUIDELINES 1. The CH1786A must be mounted in the final assembly such that it is isolated from exposure to any hazardous voltages within the assembly. Adequate separation and restraint of cables and cords must be provided. 2. The circuitry from the CH1786A to the telephone line interface must be provided in wiring that carries no other circuitry other than that specifically allowed in the FCC rules (such as A and A1 leads). 3. Connection to phone line should be made through an RJ-11C jack. 4. PCB traces from the modem's RING and TIP pins to the RJ-11C jack must be 0.1 inch spacing or greater to one another and 0.2 inch spacing or greater to all other traces. The traces should have a nominal width of 0.020 inches or greater. 5. The RING and TIP PCB traces should be as short as possible and oriented to prevent coupling other high speed or high frequency signals present on the host circuit PCB. 6. No additional circuitry other than that shown in Figure 6 may be connected between the modem module and the RJ-11C jack. Doing so will invalidate the FCC approval. 7. Surge protection is provided internally. (See Figure 6). This is mandatory to maintain FCC Part 68 conveyed approval. 8. The CH1786A, the RJ-11C jack, the interfacing circuitry and all PCB traces in between, must be contained on a PCB with a 94 V-0 flammability rating. 9. The supplied FCC registration label must be applied visibly on the outside of the product. required by the CH1786A depending on user's initialization string. Unused outputs (from modem) should be left unconnected. Unused inputs should be set to the proper logic level. See Table 2. 2006 Cermetek Microelectronics, Inc. Page 13 10. The product's User Manual must provide the user with instructions for connection and use as recommended in the FCC Registration Section below. Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems notice is recommended and should be included in the end product's user manual. CH1786A HANDLING AND ASSEMBLY RECOMMENDATIONS The CH1786A contains static-sensitive components and should only be handled by personnel and in areas that are properly protected against static discharge. The two recommended mounting techniques for physically connecting the CH1786A to a PCB are discussed below. Direct Soldering. The CH1786A may be wave soldered. All CH1786A products are hermetically sealed and will not be harmed by industry standard wave soldering processes. Socketing. The socketing approach to mounting eliminates cleaning and desoldering concerns. When the socket is used, it must make a solid connection to all pins. Failure to do so will cause unreliable or intermittent operation. Also, steps should be taken to assure that the module remains tightly seated in the socket during shipping. Cermetek recommends using sockets from Samtec. See Application Note # 130, Summary of Recommended Suppliers. FOR YOUR USER'S MANUAL The FCC Part 68 rules require the following (or equivalent) be provided to the end user of equipment containing a DAA. Type of Service. The (insert end product name) is designed to be used on standard device telephone lines. It connects to the telephone line by means of a standard jack called the USOC RJ-11C (or USOC RJ45S). Connection to telephone-company-provided coin service (central office implemented systems) is prohibited. Connection to party lines service is subject to state tariffs. Changes in Attestation Procedure for Plugs and Jacks. (Name of applicant) attests that the network interface plugs or jacks used on this equipment comply with and will continue to comply with the mechanical requirements specified in Part 68, sub-part F, specifically the dimensions, tolerances and metallic plating requirements. The compliance of these connectors will be assured by purchase specifications and incoming inspection. Documentation of such specifications and/ or inspections will be provided to the FCC within 30 days of their request for the same. Telephone Company Procedures. The goal of the telephone company is to provide you with the best service it can. In order to do this, it may occasionally be necessary for them to make changes in their equipment, operations or procedures. If theses changes might affect your service or the operation of your equipment, the telephone company will give you notice, in writing, to allow you to make any changes necessary to maintain uninterrupted service. Figure 5. Speaker Control Circuit: Optional to allow for call progress monitoring. FCC REGISTRATION All products in the CH1786A family are registered with the FCC (Federal Communications Commission) under Part 68. To maintain the validity of the registration, you must serve notice to the end user of the products of several restrictions the FCC places on the modem and its use. In addition to restriction notification, the FCC requires that Cermetek make all repairs to all products in the CH1786A family. If repairs are necessary after installation of the CH1786A in the end product and the end product has been delivered to the end user, the end product must be returned to the end product supplier where the CH1786A can be removed and then forward to Cermetek for repair. The following 2006 Cermetek Microelectronics, Inc. Page 14 In certain circumstances, it may be necessary for the telephone company to request information from you concerning the equipment which you have connected to your telephone line. Upon request of the telephone company, provide the FCC registration number and the ringer equivalence number (REN); both of these items are listed on the equipment label. The sum of all of the REN's on your telephone lines should be less than five in order to assure proper service from the telephone company. In some cases, a sum of five may not be useable on given line. Consult your telephone provider. If Problems Arise. If any of your telephone equipment is not operating properly, you should immediately remove it from your telephone line, as it may cause harm to the telephone network. If the telephone company notes a problem, they may temporarily discontinue service. When practical, they will notify you in advance of this disconnection. If Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems advance notice is not feasible, you will be notified as soon as possible. When you are notified, you will be given the opportunity to correct the problem and informed of your right to file a complaint with the FCC. Contact your local telephone service provider if you have nay questions about your phone line. In the event repairs are ever needed on the (insert your product name), they should be performed by (insert your company name) or an authorized representative of (insert your company name). For information contact: (insert your company address). DEFAULT STATUS, PERFORMANCE, AND SPECIFICATIONS Factory Defaults. The following is a summary of the Default Configuration Profile installed by Cermetek Microelectronics, Incorporated, prior to delivery of the CH1786A. Async mode selected 2400bps Even parity Auto answer enabled Command echo ON Error correction OFF All result codes enabled -extended Wait for dial tone before dialing =2 seconds Detects busy signal Full word result codes Pulse dial make/break ratio =39/61 DSR enabled Modem enabled DTR DCD enabled Speaker enabled but off when receiving carrier Speaker volume set to low Guard tones disabled 2006 Cermetek Microelectronics, Inc. Minimum DTR pulse width =0.1 seconds Ring count =01 Escape code character =43 Carriage return character =13 Line feed character =10 Back space character =08 Duration of wait for dial tone =02 seconds Duration of wait for carrier after dialing =30 seconds Duration of dial pulse (comma)=02 seconds Carrier detect response time =0.1 seconds Escape code guard time =1 second Length of use after comma =2.0 seconds Last carrier to hang up delay =0.1 seconds DTMF interdigit delay =0.1 seconds Sleep mode inactivity time = off Long space disconnect disabled V.22B selected Factory Pre-Configuration. Cermetek pre-configures the CH1786A modems with the following command set: Enter: AT+MS=V22B,1,300,2400,300,2400<CR> Result: OK Enter: ATS0=1%C0&C1&D0&S1&Q6\N0&Y0&W0<CR> Result: OK IMPORTANT NOTE If the AT&F, AT&F0 or AT&F1 commands are executed by the user, the Factory Pre-configuration commands specified above must be executed after the AT&F, AT&F0 or AT&F1 commands to ensure proper configuration setup of the CH1786A Page 15 Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems All models except CH1786AL and CH1786AN Figure 6. PSTN Line Interface for all CH1786A Products. CH1786AL and CH1786AN models do NOT contain internal Surge Protection (Dashed Box 2). The purchaser MUST be provide external surge protection to maintain conveyed FCC Part 68 approval. 1. Current Limiting PSTN Protection Line Device. Current limiting devices are mandatory to meet UL safety standards. To maintain conveyed FCC Part 68 approval, the current limiting components identified as F1 and F2 in dashed Box 1 must also survive FCC Part 68 surge testing. Refer to Cermetek Application Note #126, Supplemental PSTN Line Protection, for more details. Refer to Application Note # 130, Summary of Recommend Suppliers, for a list of suppliers and associated part numbers. A resettable/repairable fuse (rated at 0.15 amps) is preferred because it resets automatically upon removal of the current flow. Non-resettable devices are also acceptable. Although CS-03 Part 1 (Canada) follows the requirements of FCC Part 68 (USA), Cermetek recommends contacting a certified independent lab to verify compliance in the specific application. 2. Over Voltage and Lightning Protection. Surge Protection is provided by internal circuitry contained within all CH1786A models except CH1786AL and CH1786AN. No additional external components are required to maintain conveyed FCC Part 68 approval for all models EXCEPT CH1786AL and CH1786AN. For CH1786AL and CH1786AN, the required surge protection (identified as D1 in Dashed Box 2) must be supplied externally. The purchaser must include some form of surge protection as described herein to maintain conveyed FCC Part 68 approval. Refer to Application Note # 130 for a list of suppliers. 3. Optional External Over Voltage and Lightning Protection. In most environments, the internal two terminal surge suppressor (see dashed Box 3) is adequate. 2006 Cermetek Microelectronics, Inc. Page 16 For severe environments, use an external three terminal device with an earth ground as is shown in dashed Box 3. 4. EMI/RFI Suppression. Suppression of emitted EMI/RFI is recommended and is typically required to obtain FCC part 15 A and/or B approval. EMI/RFI suppression circuitry is also used to suppress reception of externally generated EMI/RFI signals, such as strong radio signals, should the CH1786A be located near a source of such signals. Although no external EMI/RFI noise suppression circuitry is required to maintain conveyed FCC Part 68 approval, additional suppression may be added as described below without adversely affecting FCC Part 68 approval. A. To provide adequate EMI/RFI suppression, the capacitor/inductor network contained in dashed Box 5 should be located as close to the RJ-11C Jack as possible. Further, this network should be provided with an excellent ground path to the chassis. B. Capacitors C1 and C2 should not exceed 0.005f. They must have a rating of 1.5KV and typically are 0.001f 20%. Inductors L1 and L2 may be either individual inductors or a dual inductor. Refer to Application Note #130 for a list of suppliers. For UL applications, choose capacitors and inductors that are UL 1950 Edition 3 listed. The actual values of the components used may vary depending on the end product design and the nature of the EMI/ RFI. Consult an FCC Part 15 consultant, if required. Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems Table 7. CH1786A System Data Mode Compatibility Specifications. Specification Parameter Specification 2400, 1200 600 bps character Receive Carrier Originate 2400Hz 7Hz asynchronous. Frequencies Answer 1200Hz 7Hz 0-300 bps asynchronous V.22 bis, V.22, 212A Asynchronous Speed TXD may differ +1%, -2.5% Bell 103 Answer `space' 2020Hz Range from modem output. Offsets 7Hz will be corrected by adding/ Answer `mark' 2225Hz deleting stop bits. 7Hz Originate 'space' 1070Hz 7Hz Originate `mark' 1270Hz 7Hz Asynchronous Format 8,9,10 bits, including start, Receiver OFF to ON threshold -43 stop, parity. Sensitivity dBm ON to OFF threshold -48 dBm Telephone Line Interface Two-wire full duplex over Billing Delay 2.0 to 3.0 seconds (Ta=25C) public switched network. Onchip hybrid and billing delay timers. Modulation V.22 bis, 16 point QAM at 600 Hysteresis 2 dB minimum baud. V.22 and 212A, 4 point DPSK at 600 baud. 103 Binary phase coherent FSK. Self Test Pattern Alternate `ones' and `zeros' Line Fixed compromise Generator and error detector, to be used Equalization equalization, transmit. along with most loopbacks. A Adaptive equalizer for number indicating the bit PSK/QAM, receive. errors detected is sent to DTE. Transmit Carrier Originate 1200Hz .01% Diagnostic Local analog loopback. &T1 Frequencies V.22 bis, Answer 2400Hz .01% Available Local analog loopback. V.22, 212A Must be used with error correction off (AT&Q6). Bell 103 Originate 'space' 1070Hz Call Progress With speaker or quiet screen .01% Tones Detected messages (No dial tone, Originate `mark' 1270Hz busy, ring, modem answer .01% tone and voice). Answer `space' 2025Hz Computer IBX PC/XT/AT bus .01% Interface compatible with an Answer `mark' 2225Hz 8250/16450/16550A UART .01% as a serial controller. Parameter Asynchronous 2006 Cermetek Microelectronics, Inc. Page 17 Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. Table 8. CH1786A Electrical Specifications. Description Min. Parameter VCC CH1786A Family of Ultra Small 2400bps Modems Positive Supply Voltage- Noise less than 50mV 4.75 Typ. Max. Units 5.0 5.25 V ICC Off Hook Nominal Operating Current when modem is OFF Hook 61 67 mA ICC On Hook ICCPD 58 0.0 64 mA mA VIH Nominal Operating Current when modem is ON Hook Power Down Current @ VCC = 5.5V when modem is in Power Down Mode2 Current Supplied into RI pin when in Power Down Mode @ VCC = 5.5V2 High Level Input Voltage1 2 VIL Low Level Input Voltage1 0 IRIPD IIN ILO VT+ Input Leakage Current (TXD, DTR, RTS) Leakage Current DCD, HS, RXD, SLEEP, DSR Positive Hysteresis Threshold for RESET pin 11.0 -10 -10 uA Vcc+. 5 0.8 V V +10 +10 3.0 uA uA V VTNegative Hysteresis Threshold for RESET pin 1.33 V 1 VOH High Level Output Voltage (IOH = 2.0mA) 2.4 V VOL Low Level (IOL = - 2.0mA)1 0.4 V Test conditions: VCC = 5V 10%, Temp = 0C to 70F (unless otherwise stated). Notes: 1. Output Load = 50 pF one TTL. 2. With recommended 30k ohm external resistor. Maximum external resistor range: 10k to 100k ohm. Parameter DC Off Hook Impedance Table 9. CH1786A Electrical Specifications. Minimum Typical Maximum Units 125 312 Ohms Trans Hybrid Loss Ring Voltage Detect 25 dB Comments @16 to 80 ma 600 Ohm, RXA, TXA 25VAC 35VAC VRMS Line Loop Current(Off-Hook) Return Loss @ 1000Hz 16 80 mA Ring Detect Frequencies 14 20 35 Hz Receiver Insertion Gain -0.5 0.0 +0.5 dBm 600 Ohm- Data Mode Transmit Power (Adjustable with S91) First Character After Reset -17.2 -13.0 -9.5 dBm Into 600 Ohm Load 0.5 1.0 5 sec Delay Inter Character Delay 20 50 msec Command Delay 100 200 msec 15 Maximum Reset Drive 0 Minimum Reset Pulse Duration 10 2006 Cermetek Microelectronics, Inc. dB 10K 600 Ohm Between all command characters Between all AT commands Ohms msec Page 18 Typically riding on 48VDC If user supplied Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems Table 10. Other Performance Specifications. Parameter DTMF total power Minimum Typical Maximum Units -5.3 -5.6 --5.8 dBm 2 3 dB DTMF Twist (Balance) Comments Into 600 ohm load DTMF Tone Duration 50 85 255 ms 85ms default Pulse Dialing Rate 8 10 20 pps 10pps default Pulse Dialing Make/ Break Pulse Interdigit Interval 39/61 700 3000 % US, Canada default ms 789ms default Guard Tone Frequency 1800 Hz Referenced to High Channel Transmit Guard Tone Amplitude -9 dB Referenced to High Channel Transmit High Channel Transmit Amplitude -1 dB Referenced to Low channel, Guard tone enabled Guard Tone 2nd Harmonic Distortion -40 dB Call Progress Passband Frequency 205 720 Hz @ -20 dBm received tone 2 255 sec Two second default dB Tr=600 Wait Time for Dial tone Return loss @ 1000Hz 15 Table 11. Analog Characteristics. Name Type SPK O(DF) 2006 Cermetek Microelectronics, Inc. Characteristic Value Minimum Load 300 Maximum Capacitive Load 0.01 Output voltage 1.65 .6V Page 19 Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. PIN NO. Figure 7. CH1786A Family of Ultra Small 2400bps Modems Table 12. CH1786A Pin Functions. PACKAGE CONNECTION TABLE FUNCTION PIN NO. FUNCTION 1 RING 12 V/D 2 TIP 13 DTR 3 RXA 14 DSR 4 TXA 15 RI 5 SPK 16 CTS 6 NC 17 DCD 7 NC 18 NC 8 SLEEP 19 VCC 9 NC 20 GND 10 TXD 21 RST 11 RXD 22 NC CH1786A Physical Dimensions. 2006 Cermetek Microelectronics, Inc. Page 20 Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. Model CH1786A Family of Ultra Small 2400bps Modems Table 13A. Summary CH1786A Family of Non-RoHS Compliant Products. Summary of Features Operating Temperature CH1786A Full Function, 2400bps, FCC Part 68 Approved, UL 1950 Listed 0C to + 70C CH1786A-C Full Function with Caller ID (CID), 2400bps, FCC Part 68 Approved, UL 1950 Listed 0C to + 70C CH1786A-L Full Function, 2400bps, FCC Part 68 Approved, UL 1950 Listed, No EEPROM, No Internal Surge Protection 0C to + 70C CH1786A-N Full Function, 2400bps, FCC Part 68 Approved, UL 1950 Listed, No EEPROM, No Internal Surge Protection, No 2-4 Wire Converter Circuit (i.e., No Voice Inject Capability) 0C to + 70C CH1786A-P Full Function with Zero Power Down, 2400bps, FCC Part 68 Approved, UL 1950 Listed 0C to + 70C CH1786A-CP Full Function with Caller ID (CID) and Zero Power Down, 2400bps, FCC Part 68 Approved, UL 1950 Listed 0C to + 70C CH1786A ET Full Function, 2400bps, FCC Part 68 Approved, UL 1950 Listed -40C to +85C CH1786A ET-C Full Function with Caller ID (CID), 2400bps, FCC Part 68 Approved, UL 1950 Listed -40C to +85C CH1786A ET-P Full Function with Zero Power Down, 14.4kbps, FCC Part 68 Approved, UL 1950 Listed -40C to +85C CH1786A ET-CP Full Function with Caller ID (CID) and Zero Power Down, 2400bps, FCC Part 68 Approved, UL 1950 Listed -40C to +85C Model Table 13B. Summary CH1786A Family of RoHS Compliant Products. Summary of Features Operating Temperature CH1786AR Full Function, 2400bps, FCC Part 68 Approved, UL 1950 Listed 0C to + 70C CH1786AR-C Full Function with Caller ID (CID), 2400bps, FCC Part 68 Approved, UL 1950 Listed 0C to + 70C CH1786AR-L Full Function, 2400bps, FCC Part 68 Approved, UL 1950 Listed, No EEPROM, No Internal Surge Protection 0C to + 70C CH1786AR-N Full Function, 2400bps, FCC Part 68 Approved, UL 1950 Listed, No EEPROM, No Internal Surge Protection, No 2-4 Wire Converter Circuit (i.e., No Voice Inject Capability) 0C to + 70C CH1786AR-P Full Function with Zero Power Down, 2400bps, FCC Part 68 Approved, UL 1950 Listed 0C to + 70C CH1786AR-CP Full Function with Caller ID (CID) and Zero Power Down, 2400bps, FCC Part 68 Approved, UL 1950 Listed 0C to + 70C CH1786AR ET Full Function, 2400bps, FCC Part 68 Approved, UL 1950 Listed -40C to +85C CH1786AR ET-C Full Function with Caller ID (CID), 2400bps, FCC Part 68 Approved, UL 1950 Listed -40C to +85C CH1786AR ET-P Full Function with Zero Power Down, 2400bps, FCC Part 68 Approved, UL 1950 Listed -40C to +85C CH1786AR ET-CP Full Function with Caller ID (CID) and Zero Power Down, 2400bps, FCC Part 68 Approved, UL 1950 Listed -40C to +85C 2006 Cermetek Microelectronics, Inc. Page 21 Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems ATTACHMENT I Page 1 of 2 Table 14. Cross Compatibility Comparison Chart. Equivalent New Model Comments Old (non "A") Model CH1786 CH1786A Standard CH1786A. No Options needed. CH1786LC CH1786A-L No EEPROM, No Internal Surge Protection. CH1786ET/PD CH1786A-ET Standard extended temp CH1786A. No options needed if Power Down not required. or CH1786NH CH1786A ET-P Standard extended temp CH1786A with Power Down option. CH1786A-N No EEPROM, No Internal Surge Protection, No 2-4 wire circuitry (i.e., No voice inject capability). Table 15. Summary of differences between CH1786 and CH1786A products. ITEM CH1786 CH1786A PIN CONFIGURATION PIN 18 HS. LOW indicates 2400bps operation. Not Supported. No Connect. ATI0. Product Code. 242 14400 ATI1. ROM Checksum. 192 042 ATI2. Checksum Verification. OK OK AFES-C2501-H0 CX81802-V32 IDENTIFICATION COMMANDS ATI3. Identify firmware code. current MODEM OPERATION COMMANDS Long Space Disconnect. ATYn command supports: Not Supported. n=0 Disables long space disconnect (default). n=1 On-Line Echo Character. Enables long space disconnect. ATFn command supports: Not Supported. n=0 Returns ERROR result code. n=1 Test and Diagnostic. Returns OK result code (default). AT&Tn command supports: AT&Tn command supports: n=0 Terminates test in progress. n=0 Terminates test in progress. n=1 Initiates Analog loopback. n=1 Initiates Analog loopback. n=2 Returns ERROR. n=2-8 Not Supported. n=3 Initiates local Digital loopback. n=4 Enables Digital loopback acknowledgement from remote RDL. n=5 Disables Digital loopback acknowledgement from remote RDL. n=6 Initiates remote Digital loopback. n=7 Initiates remote Digital loopback with self test. n=8 Initiates local Analog loopback with self test. NOTE: The identification code returned when the I0, I1, I3 commands are executed may vary, depending on manufacture date. 2006 Cermetek Microelectronics, Inc. Page 22 Document No. 607-0019 Revision A8 (03/06) Cermetek Microelectronics, Inc. CH1786A Family of Ultra Small 2400bps Modems ATTACHMENT I Page 2 of 2 Table 14. Summary of differences between CH1786 and CH1786A products (Continued). ITEM CH1786 CH1786A FAX OPERATION COMMANDS Flow Control. AT+FF command supports: AT+FLO command supports: n=0 Disable enhanced flow control (default). EIA-578 standard. n=0 XON/XOFF and RTS/CTS flow control turned off (default). n=1 Enables control. n=1 XON/XOFF flow control on in both directions. enhanced flow n=2 Use RTS for flow control of modem by DTE; use CTS flow control of DTE by modem. Transmit Test Data. +FTTn=m command. Not Supported. Receive Test Data. +FRTn command. Not Supported. NVRAM Stored Telephone Number Length 36 digits (maximum) 31 digits (maximum) STORED PARAMETERS Retrieval of factory default profiles. Execute AT&F or AT&F1 to retrieve Firmware Default setup parameters. Execute AT&F, AT&F0 or AT&F1 to retrieve Firmware Default setup parameters. To restore the CH1786A to the CH1786 default configuration, the following commands MUST be executed after executing the AT&F, AT&F0 or AT&F1 commands: Enter: AT+MS=V22B,1,300,2400,300,2400<CR> Result: OK Enter: ATS0=1%C0&C1&D0&S1&Q6\N0&Y0&W0<CR> Result: OK Cermetek reserves the right to make changes in specifications at any time and without notice. The information furnished by Cermetek in this publication is believed to be accurate and reliable. However, Cermetek assumes no responsibility for its use, or for any infringements of patents or other rights of third parties resulting from its use. No license is granted under any patents or patent rights of Cermetek. Cermetek provides the user with a FCC (USA) and IC (Canada) Approved or device. However, Cermetek does not have influence over nor knowledge of the specific user application environment. Therefore, for FCC and IC Approved or Approvable devices, the user assumes all risk for maintaining compliance to registration. Printed in U.S.A 1390 BORREGAS AVNUE | SUNNYVALE CA 94089 | LOCAL: 408-752-5000 | TOLL FREE: 1-800-882-6271 | FAX: 408-752-5004 CERMETEK WEB SITE: http://www.cermetek.com | EMAIL: sales@cermetek.com 2006 Cermetek Microelectronics, Inc. Page 23 Document No. 607-0019 Revision A8 (03/06)