ATD05 command via API fails with 'Invalid Parameter'

XB24-ZB, F/Ware 23A7 (Zigbee Router API) API-1
I’m trying to send AT commands to the device via API, using the XCTU Console. I can send, e.g, D0 and get back the D0 parameter successfully. However when I send D05 (to set the D0pin HIGH), I get back ‘Invalid Parameter’.
The sent frame is:
7E 00 05 08 01 44 30 35 4D
The received frame is:
7E 00 05 88 01 44 30 03 FF

I can succesfully send a NI frame and modify the NI parameter.
It seems that I can send commands to modify ASCII parameters (like Node Identifier), but not ones which have a numeric value (like 5)


I’ll answer my own question - the parameter has to be supplied as a binary value, not a character. So ATD05 has to be sent (in API2 mode) as
7E 00 05 08 01 44 30 05 7D 5D
7E 00 05 08 01 44 30 35 4D