BECKHOFF KL6001 - Manual (Page 14)

Data transfer, function
14 KL6001
Example 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,
Byte0
Control
Byte1
Not used
Byte2
Data OUT, high byte
Byte3
Data OUT, low byte
0x88 0xXX 0xXX 0xXX
the terminal returns the following type designation (0x0BCE corresponds to
the unsigned integer 3022).
Byte0
Status
Byte1
Not used
Byte2
Data IN, high byte
Byte3
Data IN, low byte
0x88 0x00 0x0B 0xCE
A further example
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,
Byte0
Control
Byte1
Not used
Byte2
Data OUT, high byte
Byte3
Data OUT, low byte
0xDF 0xXX 0x12 0x35
the user code word is set and the terminal returns the register address with
the bit 7 for register access and the acknowledgement.
Byte0
Status
Byte1
Not used
Byte2
Data IN, high byte
Byte3
Data IN, low byte
0x9F 0x00 0x00 0x00
Data transfer, function
Control byte in
process data transfer The control byte is transferred from the terminal to the controller. It can be
used in the register mode (REG = 1) or in the process data transfer (REG =
0) (see remark in the annex). The control and status byte in process data
transfer is used to handle data transfer (handshake)
MSB
REG=0 OL2 OL1 OL0 0 IR RA TR
Status byte in
process data mode
The status byte is transferred from the terminal to the controller. It contains
the data needed for the handshake.
MSB
REG=0 IL2 IL1 IL0 BUF_F IA RR TA
TR/TA:TRANSMIT-
REQUEST/ TRANSMIT-
ACCEPTED bits
The handshake for sending the data is realized by way of this bit. A change
of state on the part of TR results in loading of the number of data items
defined via OL0-OL2 (up to 5) into the send FIFO. The terminal signals
execution of this command via TA.