B-4 APPENDIX B: AT COMMANDS, S REGISTERS, AND RESULT CODES

S Registers

Table B-2provides a complete list and descriptions of the S registers supported by the 3C882 ISDN modem. All

S registers except S0 are the 3Com extended registers.

S registers notated with an asterisk are stored in nonvolatile memory and will not be cleared or returned to the default value if the ISDN modem is powered down.

Table B-2 S Registers

Registers

Descriptions

 

 

S0

Auto Answer:

 

0

— Disabled (default)

 

X— Number of rings before auto answer (1-255).

S50*

ISDN Switch Signaling Type:

 

0

— Unknown (default)

 

1

— AT&T 5ESS Custom

 

3

— NI1/AT&T 5ESS

 

6

— NI1/NTI DMS 100 or Siemens EWSD

S51*

Phone #1

S52*

Phone #1 Service Profile ID (SPID)

S53*

Phone #2 (if required by your carrier)

S54*

Phone #2 Service Profile ID (SPID) (if required by your carrier)

S55

Terminal Endpoint Identifier 1:

 

Stores the first TEI assigned by the switch. A value of 255 indicates no TEI

 

has been assigned. This field is read-only.

S56

Terminal Endpoint Identifier 2:

 

Stores the second TEI assigned by the switch if a second directory number is

 

required by your carrier. A value of 255 indicates no TEI has been assigned.

 

This field is read-only.

S57

Terminal Initialization State:

 

Indicates the status of the first TEI using SPID 1. This field is read-only.

 

0

— ISDN modem has not attempted initialization

 

1

— ISDN modem has initialized successfully using SPID 1

 

2

— ISDN modem has failed initialization using SPID 1