Fax Modem (250-3581) S Registers Faxback Doc. # 5876 The S registers are summarized in Table 3-1 along with their default values. Registers denoted with '*' in Table 3-1 may be stored in one of the two user profiles by entering the AT&Wn command. One of these profiles may be loaded at any time by using the ATZn command. The S registers are described in detail in Table 3-2. 3.1 FACTORY DEFAULTS The factory default values are stored in ROM and are loaded into the active configuration at power up or by the ATZn command. In addition, the designated default profile is subsequently loaded, and may change some of the factory default value. The designated default profile can be changed by entering the AT&Yn command where n is one of the two possible user profiles. All of the factory default values may be loaded at any time by entering the AT&F command. TABLE 3-1. S REGISTER SUMMARY REGISTER TITLE DEFAULT S0* Number of Rings till Auto-Answer 0 S1 Ringer Counter 0 S2* Escape Character 43 S3 Carriage Return Character 13 S4 Line Feed Character 10 S5 Back Space Character 8 S6* Wait For Blind Dialing 2 S7* Wait For Carrier After Dial 30 S8* Pause Timer For Dial Delay 2 S9* Carrier Detect Response Time 6 S10* Lost Carrier To Hang Up Delay 14 S11* DTMF Tone Duration 95 S12* Escape Code Guard Time 50 S13 Reserved none S14* Bit Mapped Test Options 171 S15 Reserved none S16 Bit Mapped Test Options 0 S17 Reserved none S18* Test Timer 0 S19 Reserved 0 S20 Reserved none S21* Bit Mapped Options 0 S22* Bit Mapped Options 118 S23* Bit Mapped Options 103 S24 Reserved none S25* Delay To DTR 5 S26* RTS To CTS Delay Interval 1 S27* Bit Mapped Options 73 S28-S29 Reserved none S30* Inactivity Timer 0 S31-S35 Reserved none S36* @ # Negotiation Failure Treatment 7 S37* Desired Telco Line Speed 0 S38* # Delay Before Forced Disconnect 20 S39* Reserved none S40 # Bit Mapped Options (MNP) 55 S41 # Bit Mapped Options (MNP) 1 S44* Unused 3 S46* @ # Protocol Selection 138 S48* @ V.42 Negotiation Action 7 S49* Speed Buffer Lower Limit 8 S50* Speed Buffer Upper Limit 255 S82 @ Break Handling 128 S86 @ Connection Failure Cause Code 0 S91* Programmable Transmit Level 0 (US) 15 (Japan) S95* @ # Extended Result Codes 0 *: Register value may be stored in one of two user profiles with the AT&Wn command. @: The register supporting V.42bis. #: The register supporting MNP. Table 3-2. S REGISTER DEFINITIONS REGISTER DESCRIPTION S0 NUMBER OF RINGS TILL AUTO-ANSWER Established the number of the rings required before the FAX Modem answer the incoming calls. Setting this register to zero disables auto-answer mode. S1 RING COUNTER Number of the rings which the FAX Modem detects before it answer a call. If no rings occur over an eight second interval, this register is cleared. S2 ESCAPE CHARACTER S2 holds the decimal value of the ACSII character used for the escape character. The default value corresponds to an ASCII "+" A value over 127 disables the escape process i.e., no escape character will be recognized. S3 CARRIAGE RETURN CHARACTER Sets the command line and result code terminator character. Pertains to asynchronous operation only. S4 LINE FEED CHARACTER Sets the character recognized as a line feed. Pertains to asynchronous operation only. The Line Feed control character is output after the Carriage Return control character if verbose result codes are used. S5 BACKSPACE CHARACTER Set the character recognized as a backspace. Pertains to asynchronous operation only. The FAX Modem will not recognize the Backspace character if it is a set value that is greater than 32 ASCII. This character can be used to edit a command line. When the echo command is enabled, the FAX Modem echoes back to the local DTE the Backspace Character; an ASCII space character and a second Backspace character; this means a total of three characters are transmitted each time the FAX Modem processes the Backspace character. S6 WAIT TIME FOR BLIND DIALING Sets the length of time to pause after the FAX Modem goes off-hook and before the FAX Modem dials the first digit of the telephone number. The FAX Modem always pauses for a minimum of 2 seconds even if the S6 register is set to a value less than 2 seconds. The "Wait For dial Tone" call progress feature (W in the dial string) will override the value in register S6. If option ATX2 or ATX4 is in effect. This register is ignored. S7 WAIT FOR CARRIER AFTER DIAL Defines Two delay times: 1. During call establishment, this register establishes the time that the local FAX Modem waits for carrier from the remote FAX Modem before hanging up. 2. Sets the length of time that the FAX Modem waits when the "Wait For Dial Tone" call progress feature (W in the dial string) is in effect. S8 PAUSE TIME FOR DIAL DELAY Sets the length of time to pause when the FAX Modem encounters the "Pause During Dial" call progress feature i.e., the comma (,). Range: 0-255 seconds S9 CARRIER DETECT RESPONSE TIME Determines how long must be present before the FAX Modem recognized it as a carrier and turns on RLSD. As this time is increased, there is less change to detect a false carrier due to noise from the telco line. S10 LOST CARRIER TO HANG UP DELAY Sets the length of time the FAX Modem waits before hanging up after a loss of carrier. This allows for a temporary carrier loss without causing the local FAX Modem to disconnect. When register S10 is set to 255, the FAX Modem functions as if a carrier is always present. The actual interval the FAX Modem waits before disconnecting is the value in register S10 minus the value in register S9, therefore, the S10 value must be great than the S9 value or else the FAX Modem disconnects before it recognized the carrier. RANGE: 1-255 tenths of a second. S11 DTMF TONE DURATION Sets the duration of tones in Dual tone Multi-frequency (DTMF) dialing. This value has no effect on pulse dialing. RANGE: 50=255 milliseconds. S12 ESCAPE CODE GUARD TIME Sets the time delay required immediately before and after entering the escape code. The time interval between the sending of the first and second, or the second and the third escape code character must be less than the value of the guard time. RANGE: 0-255 fiftieths of a second. S13 RESERVED. S14 BIT MAPPED OPTIONS Indicates the status of command options. DEFAULT: 171 Bit 0 = ATF 0-Disabled 1-Enabled Bit 1 = ATE 0-Disabled 1-Enabled Bit 2 = ATQ 0-Disabled 1-Enabled Bit 3 = ATV 0 - Numeric 1 - Verbose Bit 4 = Reserved Bit 5 = ATP or ATT 0 - ATT 1 - ATP Bit 6 = Part of ATQ 0 - ATQ0,1 1 - ATQ2 Bit 7 = Originate/Answer 0 - Disable 1 - Enable S15 RESERVED. S16 BIT MAPPED TEST OPTIONS Indicates the test in progress. The AT&T0 command any test and sets S16 to Zero. DEFAULT: 0 Bit 0 = Local analog loopback (AT&T1) 0 - Disabled (default) 1 - Enabled Bit 1 = Not used Bit 2 = Local digital loopback (AT&T3) 0 - Disable (default) 1 - Enable Bit 3 = Remote digital loopback status (AT&T4 and T5) 0 - Loopback off 1 - Loopback in progress. Bit 4 = Remote digital loopback (AT&T6) 0 - Disabled (default) 1 - Enabled Bit 5 = Remote digital loopback with self test (AT&T7) 0 - Disabled (default) 1 - Enabled Bit 6 = Local analog loopback with self test (AT&T8) 0 - Disabled (default) 1 - Enabled Bit 7 = Not used S17 RESERVED S18 TEST TIMER Sets the length of time the FAX Modem conducts a test before returning to the command mode. If this register is zero, the test will not automatically terminate; the test must be terminated from the command mode by issuing an AT&T0 or ATH command. RANGE: 0-255 seconds. S19 RESERVED S20 RESERVED S21 BIT MAPPED OPTIONS Indicates the status of command options. DEFAULT: 0 Bit 0 = Reserved Bit 1 0 = AT&YO 1 = AT&Y1 Bit 2 0 = AT&RO 1 = AT&R1 Bit 3,4 0 = AT7D0 1 = AT&D1 2 = AT&D2 3 = AT&D3 Bit 5 0 = AT&C0 1 = AT&C1 Bit 6 0 = AT&S0 1 = AT&S1 Bit 7 0 = ATY0 1 = ATY1 S22 BIT MAPPED OPTIONS Indicates the status of command options. DEFAULT: 118 Bit 0,1 0 = ATL0 1 = ATL1 2 = ATL2 3 = ATL3 Bit 2,3 0 = ATM0 1 = ATM1 2 = ATM2 3 = ATM3 Bit 4,5,6 0 = ATX0 1 = ATX1 2 = ATX2 3 = ATX3 3 = ATX4 Bit 7 0 = AT&P0 1 = AT&P1 Continued on Faxback Document # 5877 (SMC-04/07/94)