BECKHOFF KL3311 - Manual (Page 18)

Register Description
16 KL3311, KL3312, KL3314 and KL3302
0
63
Terminal´s
register set
64 words
Control-/
status byte
User data
K-Bus
If control bit 7=0: input/output
If control bit 7=1:
register-
configuration
C/S-bit 7
If control bit 7=1:
adress in the control bit 0-5
If control bit 6=0: read
If control bit 6=1: write
Complex bus terminal
To the bus coupler
H
H
L
L
2 or mors bytes
The control or status byte occupies the lowest address of a logical channel.
The corresponding register values are located in the following 2 data bytes.
(The BK2000 is an exception: here, an unused (reserved) data byte is
automatically inserted after the control or status byte, and the register
value is therefore placed on a word boundary).
Example 1 Reading of register 8 in the BK2000 with a KL3312 and the end terminal:
If the following bytes are transferred from the control to the terminal,
Byte Byte 3 Byte 2 Byte 1 Byte 0
Name DataOUT 1 DataOUT 0 Not used Control byte
Value 0xXX 0xXX 0xXX 0x88
the terminal returns the following type identifier (0x0CF0 corresponds to
unsigned integer 3312).
Byte Byte 3 Byte 2 Byte 1 Byte 0
Name DataIN 1 DataIN 0 Not used Status byte
Value 0x0C 0xF0 0x00 0x88
Example 2
Writing of register 31 in the BK2000 with an intelligent terminal and the end
terminal:
If the following bytes (code word) are transferred from the control to the
terminal,
Byte Byte 3 Byte 2 Byte 1 Byte 0
Name DataOUT 1 DataOUT 0 Not used Control byte
Value 0x12 0x35 0xXX 0xDF
the code word is set, and the terminal returns the register address with bit
7 for register access as acknowledgement.
Byte Byte 3 Byte 2 Byte 1 Byte 0
Name DataIN 1 DataIN 0 Not used Status byte
Value 0x00 0x00 0x00 0x9F