ZyXEL Communications omni series User Manual
V.110 and Synchronous Mode Communications 53
There are two modes of synchronous operation:
1. Asynchronous commands, synchronous data (AT&M1): The
omni accepts AT commands in asynchronous mode. Once the
call is connected, it enters synchronous mode for data
transmission.
call is connected, it enters synchronous mode for data
transmission.
2. Synchronous mode (AT&M3*I1): The omni accepts
synchronous commands from V.25 bis or a PC with an add-on
synchronous card, and exchanges data synchronously with a
remote TA.
synchronous card, and exchanges data synchronously with a
remote TA.
O Note: The omni does not support network independent clock
compensation. The synchronous timing source must be supplied
by the omni , which is phase locked to the network synchronous
by the omni , which is phase locked to the network synchronous
clock.
When in V.25bis command mode, the omni supports the bit-oriented
HDLC (High-Level Link Control) synchronous protocol which most
synchronous communication links use. Use AT*Ii to enable V.25bis
commands. For synchronous applications the TA is set for use with
one application, in normal situations. Save the desired settings in the
power-on profile and the TA will start up in synchronous mode with
V.25bis enabled. A special command set RST is provided to get the
TA back to asynchronous AT command mode from V.25bis mode.
HDLC (High-Level Link Control) synchronous protocol which most
synchronous communication links use. Use AT*Ii to enable V.25bis
commands. For synchronous applications the TA is set for use with
one application, in normal situations. Save the desired settings in the
power-on profile and the TA will start up in synchronous mode with
V.25bis enabled. A special command set RST is provided to get the
TA back to asynchronous AT command mode from V.25bis mode.
When the TA is used as a DCE device with a router or main-frame
system, use the following command string for best results:
system, use the following command string for best results:
AT&S1&M3*I1&W0Z0
V.25bis Command Set
Command Messages
CRN <dial string
CRN <dial string
Dial command with number provided.
CRSn
Dial command with number from memory,
0<=n<=39; n is the memory location.
0<=n<=39; n is the memory location.
PRNn;<number>
Saves <number> to address n (0<=n<=39).
CIC
Receive incoming calls.
DIC
Reject incoming calls.