3COM CORPORATION AUTO DIAL 21A Card Type Modem (asynchronous) Chip Set U.S. Robotics Maximum Data Rate 1200bps Data Bus External Data Modulation Protocol Bell 212A 54164 CONNECTIONS Function Label Function Label Line out/in - unidentified CN1 DC power CN4 Line in/out - unidentified CN2 Power switch SW1 RS-232/422 CN3 Analog loopback switch SW2 USER CONFIGURABLE SETTINGS Setting Label Position Auto answer disabled SW3/A Off Auto answer enabled SW3/A On CD normal SW3/B On CD forced high SW3/B Off Equalize for dial-up phone lines SW3/C Off Equalize for dedicated phone lines SW3/C On DTR normal SW3/D Off DTR forced high SW3/D On RS232C Setting SW4/A SW4/B SW4/C SW4/D Pin 2 receive/Pin 3 On On Off Off send Pin 2 send/Pin 3 Off Off On On receive MISCELLANEOUS TECHNICAL NOTES Note: Diagram not available. DIAGNOSTIC LED(S) LED Color Status Condition CD Red On Carrier signal detected CD Red Off Carrier signal not detected HS Red On Modem is operating at 1200bps HS Red Off Modem is operating at slower than 1200bps OH Red On Modem is off-hook OH Red Off Modem is on-hook TR Red On DTR signal is high TR Red Off DTR signal is low RD Red On Modem is receiving data RD Red Off Modem is not receiving data AN Red On Auto-answer enabled AN Red Off Auto-answer disabled SD Red On Modem is transmitting data SD Red Off Modem is not transmitting data AL Red On Modem is in analog loopback test mode AL Red Off Modem is not in analog loopback test mode ON Red On Power is on ON Red Off Power is off Proprietary AT Command Set ABORT Type: Immediate Format: Any key Description: Aborts dialing command issued; modem hangs up. ANSWER Type: Immediate Format: AT [cmds] A Description: Enables answer mode, the modem goes off-hook. ATTENTION Type: Immediate Format: AT [cmds] Description: Tells the modem that a command follows or use alone to test OK result code DIAL Type: Immediate Format: AT [cmds] D<#> [cmds] Example: ATDT 443-3388,,,1111; Description: Dials telephone number according to any modifiers included in the string Note: Any combination of modifiers can be used to produce the desired dial functions in sequence. Command Function P Pulse dialing enabled T Tone dialing enabled , Dialing paused for 2 seconds ECHO Type: Configuration Format: AT [cmds] En [cmds] Description: Controls echo function; display keyboard commands when enabled. Command Function E0 Echo function disabled E1 Echo function enabled ECHO - ON-LINE Type: Configuration Format: AT [cmds] Fn [cmds] Description: Selects whether commands sent while in data mode are echoed Command Function F0 Local echo enabled F1 Local echo disabled ESCAPE SEQUENCE Type: Immediate Format: +++AT [cmds] Description: Initiates the escape sequence and returns the modem to the on-line command state if it receives three escape characters set in S2 within the time allotted by S12. Note: Do not precede this command with AT. PULSE DIALING Type: Configuration Format: AT [cmds] P [cmds] Description: Enables pulse dialing Note: This command can be duplicated with the P modifier in the D (Dial) command. REPEAT PREVIOUS COMMAND Type: Immediate Format: A/ Description: Repeats previous command, mainly used for redial Note: Do not precede this command with AT, or follow it with . RESET Type: Immediate Format: AT [cmds] Z [cmds] Description: Resets the modem and clears all registers to default values RESULT CODES Type: Configuration Format: AT [cmds] Qn [cmds] Description: Enables modem to send result codes to the DTE Command Function Q0 Result code sending enabled Q1 Result code sending disabled RESULT CODE FORMAT Type: Configuration Format: AT [cmds] Vn [cmds] Description: Selects word or numeric format for information-text and result codes Command Function V0 Numeric format enabled V1 Verbose (word) format enabled SELECT CALL PROGRESS RESULT CODES Type: Configuration Format: AT [cmds] Xn [cmds] Description: Enables selection of tone detection and associated result code format options Command Function X0 Extended result codes disabled; result codes 0-4 enabled. X1 Extended result codes enabled; result codes 0-5 enabled SPEAKER MODE Type: Configuration Format: AT [cmds] Mn [cmds] Description: Selects various speaker options Command Function M0 Speaker disabled M1 Speaker enabled until carrier signal detected M2 Speaker enabled STATUS-REGISTER Type: Configuration Format: AT [cmds] Sn=x [cmds] Description: Writes to a specified register, values ranging from 0-255. Command Function S0=x Sets the number of rings allowed before the modem automatically goes off-hook. S0=0 will disable auto-answer. S2=x Selects a character used for the escape sequence. Default = 43 S7=x Maximum wait time in seconds the modem uses after dialing to detect a carrier signal from the remote modem for both originating and answering calls. Default = 30 TONE DIALING Type: Configuration Format: AT [cmds] T [cmds] Description: Enables tone dialing mode Note: This command can be duplicated with the T modifier in the D (Dial) command.