APPENDIX C. S REGISTERS

 

5

ATX2

 

6

ATX3

 

7

ATX4

Bit 7

Reserved

S23 * Bit mapped options

Bit 0

0AT&T5

1AT&T4

Bit 1-3 Local DTE rate

00-300bps

1600bps

21200bps

32400bps

44800bps

59600bps

619200bps

738400bps

Bit 4,5 Parity option

 

0

even

 

 

1

not used

 

 

2

odd

 

 

3

none

 

 

Bit 6,7

 

 

 

0

AT&G0

 

 

1

AT&G1

 

 

2

AT&G2

 

S24

Reserved

 

 

S25

Delay to DTR

 

Default : 5

 

Register S25 serves two purposes. When the modem is operating in

 

synchronous mode 1, the value assigned to S25 specifies the length of

 

time which the modem waits after a connection has been made before

 

examining DTR. This allows the modem to ignore an ON-to-OFF

 

transition of DTR giving the user sufficient time to disconnect the

 

modem from the asynchronous terminal and attach it to a synchronous

 

terminal, without forcing the modem back to the asynchronous

 

command mode. During this time, the value for S25 is read in seconds

 

(e.g., the factory-set value of 5 equals 5 seconds).

 

 

In all other modes, and after call establishment in synchronous modes 1

 

and 4, the value is read in 1/100 second. In any mode, a change in DTR

 

(ON or OFF) that persists for a period shorter than the value held in S25

 

is ignored by the modem while it is in data mode.

 

S26

RTS to CTS delay interval

Default : 1

 

Pertains to synchronous operation only. When CTS tracks RTS

 

(AT&R0) and the modem detects an ON-to-OFF transition on RTS, this

ACTIVE Professional External Modem User’s Manual

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