Manuals

S-Registers: Xircom® RealPort™ Ethernet 10/100+Modem 56 User's Guide

	Introduction to S-Registers
	S-Register Reference

Introduction to S-Registers

The Xircom modem uses memory storage locations, or S-Registers, to hold information controlling its operating environment. Few of these S-Registers require attention from modem users. S-Registers are used in conjunction with the AT modem commands.

To display the value of an S-Register, type ATSn? where n is the number of the S-Register, then press <Enter>.

To modify the value of an S-Register, type ATSn=r where n is the S-Register number and r is the new value or setting, then press <Enter>.

S-Register Reference

S0 Ring to Answer After

The contents of register S0 sets the number of rings required before the modem goes off-hook to answer an incoming call (auto answer). The value can range from 0 to 255. ATS0=0 disables the auto-answer function. The default is 0.

S1 Ring Counter

This register is read only. The value of S1 increments with each ring. If no rings occur over a six-second interval, the register is cleared. The value of S1 can range from 0 to 255. The default is 0. There may be country-specific limits.

S2 AT Escape Character

Register S2 defines the ASCII character used in the Escape sequence. This command is used to return to command mode without losing the connection with a remote modem. Default is S2=43, which is the �+� character. Thus the default Escape sequence is +++. ASCII values 127 and below can be used. To disable this Escape sequence, set S2 equal to a value greater than 127.

S3 Command Line Termination Character

This register contains the ASCII value of the command line terminating character (carriage return). The factory default value is ASCII 13 � the carriage return character. You can set register S3 to any value between 0 and 127.

S4 Response Formatting Character

This register contains the ASCII value of the line feed character. The factory default value is 10. You can set register S4 to any value between 0 and 127. The modem uses a line feed character in command mode when it responds to the computer.

S5 Command Line Editing Character

This register contains the ASCII value of the backspace character and is applicable to asynchronous transmissions only. The factory default value is 8. You can set register S5 to any value between 0 and 32, or to 127. The modem will not recognize the backspace character if it is set to a value greater than ASCII 32.

S6 Wait Before Blind Dialing

This register determines how long the modem waits after going off-hook before dialing the first digit. The wait must be at least 2 seconds. Register S6 can be set to any value between 2 and 65 seconds. The default is 2 seconds. The value of the W dial modifier will override the value in register S6. This operation, however, may be affected by some ATX options according to country restrictions. There may be country-specific defaults and limits.

S7 Connection Completion Time-Out

This register determines the number of seconds the originating modem waits for a carrier signal from the answering modem before hanging up. The timer is started when the modem finishes dialing (originate), or goes off-hook (answer). In originate mode, the timer is reset upon detection of an answer tone if allowed by country restriction. The timer also specifies the wait for silence time with the @ dial modifier (in seconds). S7 is not associated with the W dial modifier. Register S7 can be set at from 1 to 255 seconds with a default of 50 seconds. There may be country-specific defaults and limits.

S8 Duration of Pause for Comma Dial Modifier

This register determines the number of seconds to pause for each comma (,) in a dial string or command line. The default is 2 seconds, but any value from zero to 65 is acceptable. Defaults and limits are country-specific.

S10 Delay Between Lost Carrier/Hang Up

This register specifies the time (in tenths of a second) that the modem waits after carrier loss before hanging up. The default is 20 (2.0 seconds). Register S10 will accept a value ranging from 1 to 254 in tenths of a second (0.1 to 25.4 seconds). There may be country-specific defaults and limits.

S11 DTMF Tone Duration

This register determines the �touch tone� dialing speed which is prefixed for each country. The value can range from 50 to 150 milliseconds. The default is 95 milliseconds. The value of register S11 has no effect on pulse dialing. There may be country-specific defaults and limits.

S12 Escape Guard Time

This register sets the value (in 20 ms increments) of the required pause after the escape sequence. Range is 0 = 255, default is 50 units of 0.02 seconds each, or one second.

S28 V.34 Modulation Enable/Disable

This register enables or disables V.34 modulation. Default setting is 1, valid values are 0 or 1. A value of zero disables V.34 modulation. Any other value in the range enables it.

S30 Inactivity Timer

The value specified by this register sets how long the modem will wait (in minutes) before disconnecting when no data is sent or received. This function is only applicable in buffer mode. It is set by AT\Tn. Values are 0-255. Default is 0 (disabled).

S34 DTE Throughput Limit

This register specifies whether the modem should limit throughput when the DTE is operating at higher speeds (57,600 or 115,200bps)

S35 Data Calling Tone

This register enables or disables a tone of a certain frequency and cadence as specified in V.25 that allows remote data/fax/voice discrimination. It is set by AT-Cn. The frequency is 1300 Hz with a cadence of 0.5 seconds on and 2 seconds off. The default is country-specific. Some countries do not allow data calling tone to be overridden.

S36 Negotiation Fallback

This register specifies the action to be taken in the event of a negotiation failure when error control is selected.

See Table 1 for S36/S48 configuration combinations.

S37 Dial Line Rate

S40 ETC Startup Autorating

S42 Auto Rate

V.32bis and V.22bis auto rate is disabled. Retrain operation is disabled or enabled in data mode, and fallback is disabled in data mode.

S43 Auto Mode

V.32bis startup auto mode operation disabled.

S46 Data Compression Selection

The setting of this register is used to turn data compression on or off. It is set by AT%Cn.

Data compression can only be enabled when the modem is operating in an error-control (EC) mode using either V.42 LAP-M or MNP protocols.

S48 LAPM Error Control and Feature Negotiation

Table 1 shows the S36 and S48 configuration settings needed to negotiate certain types of connections.

Table 1. S36/S48 Configuration Combinations

S89 Timer to Control Sleep Mode

This register displays the number of seconds of inactivity (no characters sent from DTE, no RING) in the off-line command state before the modem places itself into standby mode. A value of zero prevents standby mode. Default is 30. Range is 0 and 5 - 65.

S91 Line Transmit Level

This register specifies the line transmit level, in dB, with an implied minus sign. Default is 15 dB, range is 6 - 15.

S92 Direct Connect Transmit Level

This register sets the transmit level, in dBm, for direct connect cellular. This value may have different settings for different phones. Default is 0 dBm.

S95 Negotiation Message Options

This register enables various result codes indicating the sequence of events in an error-controlled connection. This S-Register does not affect the way the connection is negotiated, it just enables extended messages.

S98 Cable Detection Options

This register controls the automatic detection and reporting of changes in the cable or alternative connector attached to the modem.

Please read all restrictions and disclaimers.