The MOACON can support up to 3 RS-232/485 channels. One (channel 0) is built into the CPU Module. Channels 1 and 2 can be found on the Communication Module.
RS-232 pin configuration is shown in the image below. Like channel 0, channels 1 and 2 have a 5V power source on pin 9, but unlike channel 0, it cannot be turned off.
On the Communication Module, channel 1 is dedicated to RS-232, but channel 2 can be switched between RS-232 and RS-485.
Only one Communication Module can be installed at a time.
As shown in the image above, Communication Module can be installed in any vacant slot on the 10-slot main board. Cannot be installed in the expansion boards.
WARNING: Do not plug or unplug modules while the power is on.