BECKHOFF KL3681 - Manual (Page 40)

Access from the user programm
• In the Status Byte, the terminal returns a value, that differs only at bit 0.6 from the value of the of the
Control Byte.
• The input data word (Byte 1 and Byte 2) has no function after the writing access. Values that might be
shown are not valid!
IV. Reading Register 32 (verifying the changed feature register)
Byte 0: Control Byte Byte 1: DataOUT1, high byte Byte 2: DataOUT1, low byte
0xA0 (1010 0000
bin
) 0xXX 0xXX
Explanation:
• Bit 0.7 set indicates register communication active.
• Bit 0.6 not set indicates reading the register.
• Bit 0.5 to Bit 0.0 indicates with 10 0000
bin
the register number 32.
• The output data word (Byte 1 and Byte 2) has no function at the reading access.
Byte 0: Status Byte Byte 1: DataIN1, high byte Byte 2: DataIN1, low byte
0xA0 (1010 0000
bin
) 0x00 0x02
Explanation:
• The terminal returns the value of the Control Byte in the Status Byte, as an acknowledgement.
• The terminal returns the current value of the feature register in the input data word (Byte 1 and Byte 2).
V. Writing to Register 31 (setting the code word back)
Byte 0: Control Byte Byte 1: DataOUT1, high byte Byte 2: DataOUT1, low byte
0xDF (1101 1111
bin
) 0x00 0x00
Explanation:
• Bit 0.7 set indicates register communication active.
• Bit 0.6 set indicates: writing to the register.
• Bit 0.5 to Bit 0.0 indicates with 01 1111
bin
the register number 31.
• The output data word (Byte 1 und Byte 2) contains 0x0000 to activate the write protection again.
Byte 0: Status Byte Byte 1: DataIN1, high byte Byte 2: DataIN1, low byte
0x9F (1001 1111
bin
) 0xXX 0xXX
Explanation:
• In the Status Byte, the terminal returns a value, that differs only at bit 0.6 from the value of the of the
Control Byte.
• The input data word (Byte 1 and Byte 2) has no function after the writing access. Values that might be
shown are not valid!
KL3681, KS3681 40 Version 2.0.0