Beckhoff KL4494, Manual

Page: 37 / 40

Access from the user program
KL4494 37 Version: 2.0.0
• The terminal returns the current value of the code word register in the input data word (byte 1 and byte
2).
III. Write to Register 32 (change contents of the feature register)
Output data
Byte 0: Control byte Byte 1: DataIN1, high byte Byte 2: DataIN1, low byte
0xE0 (1110 0000
bin
) 0x00 0x02
Explanation:
• Bit 0.7 set means: Register communication switched on.
• Bit 0.6 set means: writing to the register.
• Bits 0.5 to 0.0 indicate register number 32 with 10 0000
bin
.
• The output data word (byte 1 and byte 2) contains the new value for the feature register.
CAUTION
Observe the register description!
The value of 0x0002 given here is just an example!
The bits of the feature register change the properties of the terminal and have a different
meaning, depending on the type of terminal. Refer to the description of the feature register
of your terminal (chapter
Register description ) regarding the meaning of the individual bits
before changing the values.
Input data (response from the Bus Terminal)
Byte 0: Status byte Byte 1: DataIN1, high byte Byte 2: DataIN1, low byte
0xA0 (1010 0000
bin
) 0xXX 0xXX
Explanation:
• The terminal returns a value as a receipt in the status byte that differs only in bit 0.6 from the value of
the control byte.
• The input data word (byte 1 and byte 2) is of no importance after the write access. Any values still
displayed are invalid!
IV. Read Register 32 (check changed feature register)
Output Data
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 means: Register communication switched on.
• Bit 0.6 not set means: reading the register.
• Bits 0.5 to 0.0 indicate register number 32 with 10 0000
bin
.
• The output data word (byte 1 and byte 2) has no meaning during read access.
Input Data (answer of the bus terminal)
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 as a receipt in the status byte.
• The terminal returns the current value of the feature register in the input data word (byte 1 and byte 2).