User's Manual

455U-D Radio Modem Module User Manual
Page 78 © Jan 2008
Appendix C S-Registers
The following table lists the S-Registers supported by the 455U-D modem.
No. Range Function Comment
S0 0-255 Attempts before Answering
Call
Should normally be set to 1. 0 disables auto
answering of calls (ATA command to answer
calls only).
S1 3-255 Escape Sequence Guard Time Units 20 milliseconds. Min. Delay before and
after entering the escape sequence (“+++”)
also Max. Delay between characters of the
escape sequence.
S2 1-255 Escape Sequence Character Normally 43 = “+”
S3 0-127 Carriage Return Character Normally 13 = <CR>
S4 0-127 Line Feed Character Normally 10 = <LF>
S5 0-127 Back Space Character Normally 8 = <BS>
S6 0-255 Inactivity Timer/Link Check
Timer
Units Seconds. 0 disables. How frequently to
send a “Link Check” message. Usually set
less than the timeout set by the AT\T
command. Default 0.
S7 1-255 Number of Connection
attempts (Acknowledged
Mode)
How many times to attempt a connection
after an ATD command. Default 5.
S8 0-255 Test Timer Units Seconds – How long to run tests
(AT&Tx)
S9 0-255 Modem Receive Level Units (-)dBm – RSSI indication of last
received message. AT&T5 command may be
more useful.
S10 0-255 DTR Loss Detection Time Units 10 milliseconds (Not Implemented)
S11 0-255 Spare Function Not Implemented
S12 read-only Command Mode
Diagnostic
Reason modem last returned to command
mode, i.e. connection lost.
S12 = 0 Reset (ATZ or Power Up).
S12 = 1 Escape sequence (“+++”)
S12 = 2 DTR lowered.
S12 = 3 No ACK from remote modem after connected.
S12 = 4 Activity timer timed out.
S12 = 5 No response to dial request to remote modem.