V.34 Faxmodem (250-3037) S-Register Explanation Faxback Doc. # 14543 S-REGISTER DEFINITIONS S0 - Number of Rings to Auto-Answer Sets the number of the rings required before the modem automatically answers a call. Setting this register lo zero disables auto-answer mode. Range: 0-255 rings Default: 0 S1 - Ring Counter S1 is incremented each time the modem detects a ring signal on the telephone line. S1 is cleared if no rings occur over an eight second interval. Range: 0-255 rings Default: 0 S2 - Escape Character S2 holds the decimal value of the ASCII character used as 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. Range: 0-255, ASCII decimal Default: 43 (+) S3 - Carriage Return Character Sets the command line and result code terminator character. Pertains to asynchronous operation only. Range: 0-127, ASCII decimal Default: 13 (Carriage Return) 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. Range: 0-127, ASCII decimal Default: 10 (Line Feed) S5 - Backspace Character This register sets the character your modem uses as a backspace character for editing. You do not normally need to change this register. The default value is 8 (ASCII backspace). S6 - Wait Time for Dial Tone Before Blind Dialing, or After "W" Dial Modifier This register sets how may seconds your modem waits to begin dialing after it goes off hook. If your modem begins dialing before the dial tone starts, your call might not go through. You can set this register to a higher value to provide a longer delay. The default value is 2 (setting to 0 or I also gives a 2 second delay). S7 - Wait Time For Carrier After Dial, For Silence, or For Dial Tone After "W" Dial Modifier This register sets how long your modem waits after dialing to detect a carrier from an answering modem. If this time expires without a carrier detect, your modem returns the NO CARRIER result code. The default value is 30. Range: 1-255 seconds Default: 50 S8 - Pause Time For Dial Delay Sets the time, in seconds, that the modem must pause when the "," dial modifier is encountered in the dial string. Range: 0-255 seconds Default: 2 S9 - Carrier Detect Response Time Sets the time, in tenths of a second, that the carrier must be present before the modem considers it valid. As this time is increased, there is less chance to detect a false carrier due to noise from the telephone line. Range: 1-255 tenths of a second Default: 6 (0.6 second) S10 - Lost Carrier To Hang Up Delay This register sets how many tenths of a second (1/10 seconds) your modem waits to disconnect from the phone line after the other modem's carrier stops. In some areas with poor quality phone service, the carrier can occasionally drop out and cause your modem to disconnect during a call. If you set this register to 255, your modem considers the carrier always present. The default value is 14 ( 1.4 seconds). S11 - DTMF Tone Duration Sets the duration of tones in DTMF dialing. This value has no effect on pulse dialing. Range: 50-255 milliseconds Default: 95 (95 milliseconds) S12 - Escape Prompt Delay (EPD) Defines the maximum period, in fiftieths of a second, allowed between receipt of the last character of the three escape character sequence from the PC and sending of the OK result code to the PC. If any characters are detected during this time, the OK will not be sent. Note that sending of the OK result code does not affect entry into command mode. Range: 0-255 1/50 of a second Default: 50 (I second) S13 - Reserved S14 - General Bit Mapped Options Status Indicates the status of command options. Default: 138 (8Ah) (10001010b) Bit 0 - This bit is ignored. Bit 1 - 0 = Disabled (E0) 1 = Enabled (El) (Default.) Bit 2 - 0 = Send result codes (Q0) (Default.) 1 = Do not send result codes (Q1) Bit 3 - 0 = Numeric (V0) 1 = Verbose (V1) (Default.) Bit 4 - Reserved Bit 5 - 0 = Tone (T) (Default.) 1 = Pulse (P) Bit 6 - Reserved Bit 7 - 0 = Answer 1 = Originate (Default.) S15 - Reserved S16 - General Bit Mapped Test Options Status Indicates the test in progress status. Default: 0 Bit 0 - 0 = Disabled (Default.) 1 = Enabled (&T1) Bit 1 - Not used Bit 2 - 0 = Disabled (Default.) 1 = Enabled (&T3) Bit 3 - 0 =Modem not in RDL (Default) 1 = RDL in progress Bit 4 - 0 =RDL not requested (Default.) 1 = RDL requested (&T6) Bit 5 - 0 =Disabled (Default.) 1 = Enabled (&T7) Bit 6 - 0 =Disabled (Default.) 1 = Enabled (&T8) Bit 7 - Not used S17 - Reserved S18 - Test Timer Sets the length of time, in seconds, that the modem conducts a test (commanded by &Tn) before returning to the command mode. If this register value is zero, the test will not automatically terminate; the test must be terminated from the command mode by issuing an &T0 or H command. When S18 is non-zero, the modem returns the OK message upon test termination. Range: 0-255 seconds Default: 0 S19 - AutoSync Bit Mapped Options Defines the options for AutoSync operation (see &Q4 command). S19 must be set to the desired value before &Q4 is issued. Default: 0 Bit 0 - Reserved Bit 1 - BSC/HDLC format select 0 = BSC selected (Default.) 1 = HDLC selected Bit 2 - Address detection enable/disable 0 = Disabled (Default.) 1 = Enabled Bit 3 - NRZI/NZI coding select 0 = NRZI (Default.) 1 = NZI Bit 4 - Idle indicator select select 0 = Mark idle (Default.) 1 = Flag or sync idle Bit 5-7- Reserved S20 - AutoSync HDLC Address or BSC Sync Character Defines the HDLC address (S19 bit 1 = 1 ) or BSC Sync Character (S19 bit 1 = 0) for AutoSync operation (see &Q4 command). S20 must be set to the desired value before &Q4 is issued. Range: 0-255 Default: 0 S21- V.24/General Bit Mapped Options Status Indicates the status of command options. Default: 4 (00000100b) Bit 0 - 0 = &JO (Default.) 1= &J1 Bit 1 - Reserved Bit 2 - 0 = CTS tracks RTS (&R0) 1 = CTS always on (&RI) (Default.) Bit 3,4 - 0 = &D0 selected (Default.) 1 = &D1 selected 2 = &D2 selected 3 = &D3 selected Bit 5 - 0 = &CO selected (Default.) 1 = &C1 selected Bit 6 - 0 = &SO selected (Default.) 1 = &S1 selected Bit 7 - 0 = Y0 (Default.) 1 = Y1 S22 - Speaker/Results Bit Mapped Options Status Indicates the status of command options. Default: 117 (75h) (01110101b) Bit 0,1 - 0 = Off (L0) 1 = Low (L1) (Default.) 2 = Medium (L2) 3 = High (L3) Bit 2,3 - 0 = Disabled (M0) 1 = Off on carrier (M1) (Default.) 2 = Always on (M2) 3 = On during handshake (M3) Bit 4,5,6- 0 = X0 4 = X1 5 = X2 6 = X3 7 = X4 (Default.) Bit 7 - Reserved S23 - General Bit Mapped Options Status Indicates the status of command options. Default: 55 (37h) (00110111b) Bit 0 - 0 = RDL not allowed (&T5) 1 = RDL allowed (&T4) (Default.) Bit 1,2,3 - PC Rate 0 = 0 - 300 bps 1 = 600 bps 2 = 1200 bps 3 = 2400 bps (Default.) 4 = 4800 bps 5 = 9600 bps 6 = 19200 bps 7 = 38400 bps or higher Bit 4,5 - 0 = even 1 = not used 2 = odd 3 = none (Default.) Bit 6,7 - 0 = None (&G0) (Default) 1 = 550 Hz (&G 1) 2 = 1800 Hz (&G2) S24 - Sleep Inactivity Timer Sets the length of time, in seconds, that the modem will operate in normal mode with no detected telephone line or PC line activity before entering low-power sleep mode. The timer is reset upon any PC line or telephone line activity. If the S24 value is zero, neither PC line nor telephone inactivity will cause the modem to enter the sleep mode. Range: 0-255 seconds Default: 0 S25 - Delay To DTR Sets the length of lime that the modem will ignore DTR for taking the action specified by &Dn. Its units are seconds for synchronous modes and one hundredths of a second for other modes. Range: 0-255 (1 second for Default: 5 synchronous modes 1; 0.01 second otherwise ) S26 - RTS to CTS Delay Sets the time delay, in hundredths of a second, before the modem turns CTS ON after detecting an OFF-to-ON transition on RTS when &R0 is commanded. Pertains to synchronous operation only. Range: 0-255 hundredths of Default: 1 a second S27 - Bit Mapped Options Status Indicates the status of command options. Default: 73 (49h) (01001001b) (US models). 9 (09h) (00001001b) (other countries.) Bit 0,1,3 -Synchronous/asynchronous selection (&Mn/&Qn) 3 1 0 0 0 0 = &MO or &Q0 0 0 1 = &M1 or &Q1 0 1 0 = &M2 or &Q2 0 1 1 = &M3 or &Q3 1 0 0 = &Q4 1 0 1 = &Q5 (Default.) 1 1 0 = &Q6 Bit 2 - 0 = Dial up line (&L0) (Default.) 1 = Leased line (&L1) Bit 4,5 - 0 = Internal clock (&X0) (Default.) 1 = External clock (&X1) 2 = Slave clock (&X2) Bit 6 - 0 = CCITT mode (B0) 1 = Bell mode (B1) Bit 7 - Reserved S28 - Bit Mapped Options Status Default: 0 Bit 0 - Reserved Bit 1 - 0 = 75 Tx /1200 Rx (%F1) (Default.) 1 = 1200 Tx /75 Rx (%F2) Bit 2 - Reserved (always 0). Bit 3,4 - 0 = 39%-61% make/break ratio at 10 pulses per second (&P0) (Default) 1 = 33%-67% make/break ratio at 10 pulses per second (&P 1) 2 = 39%-61% make/break ratio at 20 pulses per second (&P2) 3 = 33%-67% make/break ratio at 20 pulses per second (&P3) Bit 5 - Reserved S29 - Flash Dial Modifier Time Sets the length of time, in units of 10 ms, that the modem will go on- hook when it encounters the flash ( !) dial modifier in the dial string. The time can be limited as it is a country dependent parameter. Range: 0-255 10 ms intervals Default: 0 (disabled) S30 - Disconnect Inactivity Timer Determines the length of lime that the modem will wait before disconnecting when no data is sent or received. Allowable range for S30 register is 0-255, in tenth of a second intervals. Default: 0 (disabled). S31 - Bit Mapped Options Status Default: 2 (00000010b) Bit 0 - Reserved Bit 1 - 0 = Disabled (N0) 1 = Enabled (N1) (Default.) Bit 2,3 - 0 = PC speed only (W0) (Default.) 1 = Full reporting (W1) 2 = modem speed only (W2) Bit 3 - Reserved Bit 4-7 - Reserved S32- X ON Character Sets the value of the XON character. Range: 0-255, ASCII decimal Default: 17 (11h) S33- X OFF Character Sets the value of the XOFF character. Range: 0-255, ASCII decimal Default: 19 (13h) S34-S35 - Reserved S36 - LAPM Failure Control Default: 7 (00000111b) Bit 0-2 - This value indicates what should happen upon a LAPM (V.42 Error Correction) failure. These fallback options are initiated immediately upon connection if S48=128. If an invalid number is entered, the number is accepted into the register, but S36 will act as if the default value has been entered. 0 = Modem disconnects. 1 = Modem stays on-line and a Direct mode connection is established. 2 = Reserved. 3 = Modem stays on-line and a Normal mode connection is established. 4 = An MNP connection is attempted and if it fails, the modem disconnects. 5 = An MNP connection is attempted and if it fails, a Direct mode connection is established. 6 = Reserved. 7 = An MNP connection is attempted and if it fails, a Normal mode connection is established. (Default.) Bit 3-7 - Reserved S37- Desired Line Connection Speed Default: 0 Bit 0-4 - Desired line connection speed. This is interlinked with the Fn command. If an invalid number is entered, the number is accepted into the register, but S37 will act as if the default value has been entered. 0 = Attempt auto mode connection (F0) (Default.) 1-3 = Attempt to connect at 300 bps (F1). 4 = Reserved. 5 = Attempt to connect at V.22 1200 bps (F4). 6 = Attempt to connect at V.22 bis 2400 bps (F5). 7 = Attempt to connect at V.23 (F3). 8 = Attempt to connect at V.32 bis/V.32 4800 bps (F6) 9 = Attempt to connect at V.32 bis/V.32 9600 bps (F8) 10 = Attempt to connect at V.32 bis 12000 bps (F9). 11 = Attempt to connect at V.32 bis 14400 bps (F10). 12 = Attempt to connect at V.32 bis 7200 bps (F7). Bit 5-7 - Reserved S38 - Delay Before Forced Hang Up This register specifies the delay between the modem's receipt of the H command to disconnect (or ON-to-OFF transition of DTR if the modem is programmed to follow the signal), and the disconnect operation. Applicable to error-correction connection only. This register can be used to ensure that data in the modem buffer is sent before the modem disconnects. 1. If S38 is set to a value between 0 and 254, the modem will wait that number of seconds for the remote modem to acknowledge all data in the modem buffer before disconnecting. If time expires before all data is sent, the NO CARRIER result code will be issued to indicate that data has been lost. If all data is transmitted prior to time-out, the response to the HO command will be OK. 2. If S38 is set to 255, the modem does not time-out and continues to attempt to deliver data in the buffer until the connection is lost or the data is delivered. Range: 0-255 seconds Default: 20 S39 - Flow Control Bit Mapped Options Status Default: 3 (00000011b) Bits 0-2 - 0 = No flow control 3 = RTS/CTS (&K3) (Default.) 4 = XON/XOFF (&K4) 5 = Transparent XON (&K5) 6 = Both methods (&K6) Bits 3-7 - Reserved S40 - General Bit Mapped Options Status Indicates the status of command options. Default: 105 (69h) (01101001b) Bit 0-1 - 0 = Disable extended services (-K0) (Default for non-MNP 10 models.) 1 = Enable extended services (-K1) (Default for MNP 10 models.) 2 = Enable extended services (-K2) Bit 2 - 0 = Auto-adjustment ()MO) (Default.) 1 = Force adjustment ()M1) Bits 3-5 - 0 = \K0 1 = \K1 2 = \K2 3 = \K3 4 = \K4 5 = \K5 (Default.) Bits 6-7 - 0 = 64 chars (\A0) 1 = 128 chars (\AI) (Default.) 2 = 192 chars (\A2) 3 = 256 chars (\A3) S41 - General Bit Mapped Options Status Indicates the status of command options. Default: 131 (10000011b) Bits 0-1 - 0 = Disabled (%C0) 1 = MNP 5 (%C1) 2 = V.42 bis (%C2) 3 = MNP 5 and V.42 bis (%C3) (Default.) Bit 2, 6 - Auto retrain and fallback/fall forward (%En) Bit 6 Bit 2 0 0 = Retrain and fallback/fall forward disabled (%E0) (Default.) 0 1 = Retrain enabled (%E1) 1 0 = Fallback/fall forward enabled (%E2) Bit 3 - 0 = Disabled (\GO) (Default.) 1 = Enabled (\G1) Bit 4 - 0 = Stream mode (\LO) (Default.) 1 = Block mode (\L1) Bit 5 - Reserved S46 - Data Compression Control Controls selection of compression. The following actions are executed for the given values: Range: 136 or 138 Default: 138 S46=136 Execute error correction protocol with no compression. S46=138 Execute error correction protocol with compression. (Default.) S48 - V.42 Negotiation Action The V.42 negotiation process determines the capabilities of the remote modem. However, when the capabilities of the remote modem are known and negotiation is unnecessary, this process can be bypassed if so desired. Range: 0, 7, or 128 If an invalid Default: 7 number is entered, it is accepted into the S-Register, but S48 will act as if 128 has been entered. S48=0 Disable negotiation; bypass the detection-and negotiation phases; and proceed with LAPM. S48=7 Enable negotiation. (Default.) S48=128 Disable negotiation; bypass the detection and negotiation phases; and proceed at once with the fallback action specified in S36. Can be used to force MNP. S80 - Soft-Switch Functions (for factory use only) S82 - Break Handling Options S82 is for compatibility purposes only, changing this register will not have any affect. S86 - Call Failure Reason Code When the modem issues a NO CARRIER result code, a value is written to this S-Register to help determine the reason for the failed connection. S86 records the first event that contributes to a NO CARRIER message. The cause codes are: Range: 0, 4, 5, 9, 12,13, or 14 Default: S86=0 Normal disconnect, no error occurred. S86=4 Loss of carrier. S86=5 V.42 negotiation failed to detect an error-correction modem at the other end. S86=9 The modems could not find a common protocol. S86=12 Normal disconnect initiated by the remote modem. S86=13 Remote modem does not respond after 10 retransmissions of the same message. S86=14 Protocol violation. S91 - PSTN Transmit Attenuation Level Sets the transmit attenuation level from 0 to 15 dBm for the PSTN mode, resulting in a transmit level from 0 to -15 dBm. In some countries, the transmit level may not be changed and there are checks to prevent transmit attenuation level change. Range: 0 to 15 dBm (Corresponding Default: 10 (-10 dBm transmit to 0 to -15 dBm level.) transmit level.) S92 - Fax Transmit Attenuation Level Sets the transmit attenuation level from 0 to 15 dBm for the fax mode, resulting in a transmit level from 0 to -15 dBm. In some countries, the transmit level may not be changed and there are checks to prevent transmit attenuation level change. Range: 0 to 15 dBm (Corres- Default: 10 (-10 dBm transmit ponding to 0 to -15 dBm level.) transmit level.) S95 - Extended Result Codes The bits in this register can be set to override some of the Wn command options. A bit set to a I in this register will enable the corresponding result code regardless of the Wn setting. Default: 0 Bit 0 - CONNECT result code indicates modem speed instead of PC speed. Bit 1 - Append/ARQ to CONNECT XXXX result code in error correction mode (XXXX = rate). Bit 2 - Enable CARRIER XXXX result code (XXXX = rate). Bit 3 - Enable PROTOCOL XXXX result code (XXXX = protocol identifier). Bit 4 - Reserved. Bit 5 - Enable COMPRESSION result code (XXXX = compression type). Bit 6 - Reserved. Bit 7 - Reserved. (ALL-04/07/95)