I’ve never tried a GC-100 on Vera.
If you want to see the datastream that an attached plugin sees, enable log levels “51” and “52” in the file:
/etc/cmh/cmh.conf
The log configuration will look like this:
LogLevels = 1,2,3,4,5,6,7,8,9,50,51,52
Log level 52 is incoming serial data (from the IT100), and 51 is outgoing (to the IT100).
The output will look like this:
grep ^5[012] LuaUPnP.log
52 08/12/14 13:19:21.106 0x36 0x35 0x30 0x31 0x43 0x43 (6501CC) <0x2d87e680>
50 08/12/14 13:19:21.106 luup_log:3: DSCAlarmPanel: debug processIncoming:: Command=650, Data='1', Checksum=CC <0x2d87e680>
50 08/12/14 13:19:21.107 luup_log:3: DSCAlarmPanel: debug Partition::Ready 650 partition: 1 <0x2d87e680>
52 08/12/14 13:19:53.599 0x35 0x35 0x30 0x31 0x36 0x32 0x30 0x30 0x38 0x31 0x32 0x31 0x34 0x39 0x33 (550162008121493) <0x2d87e680>
50 08/12/14 13:19:53.599 luup_log:3: DSCAlarmPanel: debug processIncoming:: Command=550, Data='1620081214', Checksum=93 <0x2d87e680>
50 08/12/14 13:19:53.601 luup_log:3: DSCAlarmPanel: debug Panel::Time/Date Broadcast (1620081214) <0x2d87e680>
52 08/12/14 13:23:30.619 0x35 0x31 0x31 0x31 0x30 0x46 0x38 (51110F8) <0x2d87e680>
50 08/12/14 13:23:30.619 luup_log:3: DSCAlarmPanel: debug processIncoming:: Command=511, Data='10', Checksum=F8 <0x2d87e680>
50 08/12/14 13:23:30.622 luup_log:3: DSCAlarmPanel: debug Panel::Keypad LED Flash State - Partition 1 only (10) <0x2d87e680>
52 08/12/14 13:23:30.623 0x38 0x34 0x39 0x30 0x35 0x30 0x41 (849050A) <0x2d87e680>
50 08/12/14 13:23:30.624 luup_log:3: DSCAlarmPanel: debug processIncoming:: Command=849, Data='05', Checksum=0A <0x2d87e680>
50 08/12/14 13:23:30.626 luup_log:3: DSCAlarmPanel: debug Verbose Trouble Status 849 <0x2d87e680>
52 08/12/14 13:23:31.119 0x35 0x31 0x30 0x38 0x30 0x46 0x45 (51080FE) <0x2d87e680>
50 08/12/14 13:23:31.120 luup_log:3: DSCAlarmPanel: debug processIncoming:: Command=510, Data='80', Checksum=FE <0x2d87e680>
If you’re not seeing that, then there’s a problem upstream somewhere (Panel, Wiring, GC100, GC100 Plugin, etc). I’ve seen cases in the past, with regular USB-Serial, where one of the wires is broken and so either TX or RX isn’t working.