Siemens SIMATIC TIWAY 1 - Manual (Page 145)

HOST COMMAND SET REFERENCE
UNILINK HOST ADAPTER 5–60
USER MANUAL
5.6.4 Switch Channel — 33
The SWITCH CHANNEL command explicitly specifies the channel to be used
for communicating with each secondary when redundant media is used. One,
several, or all secondaries may be switched to the alternate media channel at
any time. This command can be used even when the auto redundant media
option is enabled; however, the Network Manager may change this user
specification without notice if a failure is detected. All secondary device
communications will take place on Channel A at initialization.
Command: 33 cc [aa]
Response: 33 cc
Usage: OPERATION
Modes: NM
Parameters:
cc The channel to switch to.
00 = Channel A
01 = Channel B
aa The secondary addresses to be switched. Special cases are:
00 = all secondaries, including the broadcast message channel
will be switched to the channel specified by ‘cc’.
FF = The channel specified by ‘cc’ will be used to send broadcast
messages.