With yesterday's linking success, I have extended the PLM protocol handler to send group commands to those devices that have a group mapping. The idea is that I don't need to add everything to make plcd continue working. When you send an on command to a mapped device, it will send the broadcast message to the corresponding group. In most cases, the commanded LED will turn on, sometimes more than one LED will turn on, but at the moment I am blaming that on shonky link tables as the devices in question have been linked and unlinked and some of them factory reset many times over the last few days, so it is pretty easy to understand that they have gotten out of whack. Needless to say, here is the obligatory debug log of a command being sent to an individual LED.

plcd[3043]: Network thread received: on for 1a1e8c03
plcd[3043]: Network thread received: get devices
plcd[3043]: Transmission sending command: on to 1a1e8c03
plcd[3043]: PLMProtocol SG            sent: 02610211ff
plcd[3043]: PLMProtocol SG received    ack: 02610211ff06
plcd[3043]: PLMProtocol SG received remote ack: 02501a1e8c1cf460661102

Now to move on and get the linking as a responder working, and have the handler sort out what each link is before adding it to the map, giving less reliance on the group number. It appears that linking via set buttons does not use the first group, it uses the next number in line. This is important as RF devices will need to be linked via set button.