For Meade at least, what is documented may not be what is fully supported, there may be other formats..
When made a few changes to the lx200 driver I also captured the communications
INDIlx200->TCP->Linux(SOCAT tcp to serial lx200)
For Autostar and lx200 classic with 3.34L roms
Unfortunately I could not find the pcap with the Sr/Sd to the lx200
Attached are snippets from Autostar and the lx200 in wireshark pcap.