Hello,
Hope this helps. I have done some protocol development for some meters (ANSI/IEC). This byte frames will work for Landis+Gyr meters if it is program to be in mode A (IEC 62056-21). The command frame is just to query the meter for data.
character frames:
/ = 2FH or AFH
? = 3FH
! = 21H
CR = 0DH
LF = 0AH
Create a Serial object in Arduino:
byte cmd[] = {0xAF,0x3F,0x21,0x8D,0x0A}
Serial.write (cmd,5);
Let me know it you are able to receive reply bytes and I'll show how to decode them.