BECKHOFF KL2521-0000 - Manual (Page 16)

Access from the user program
14 KL2521
Examples for Register Communication
Example 1 Reading register 8 in the BK2000 with a Kl3022 and the end terminal.
If the following bytes are transferred from the controller to the terminal,
Byte Byte3 Byte2 Byte1 Byte0
Name Data OUT, low byte Data OUT, high byte Not used Control
Value 0xXX 0xXX 0xXX 0x88
the terminal returns the following type designation (0x0BCE corresponds to
the unsigned integer 3022).
Byte Byte3 Byte2 Byte1 Byte0
Name Data IN, low byte Data IN, high byte Not used Status
Value 0xCE 0x0B 0x00 0x88
Example 2
Writing register 31 in the BK2000 with an intelligent terminal and the end
terminal.
If the following bytes (user code word) are transferred from the controller to
the terminal,
Byte Byte3 Byte2 Byte1 Byte0
Name Data OUT, low byte Data OUT, high byte Not used Control
Value 0x35 0x12 0xXX 0xDF
the user code word is set and the terminal returns the register address with
the bit 7 for register access and the acknowledgement.
Byte Byte3 Byte2 Byte1 Byte0
Name Data IN, low byte Data IN, high byte Not used Status
Value 0x00 0x00 0x00 0x9F