750-654, 750-654/000-001 [Data Exchange Module]
•
11
Data Transfer
WAGO-I/O-SYSTEM 750
I/O Modules
X not
used
0
Constant value must always be 0
Status byte
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0 X X
RCVT1
RCVT2
CHK
OVR
PAR
PAR
Parity error or wrong data in a frame.
OVR
Buffer overflow
CHK Checksum
error.
RCVT2
The receiver is in timeout.
RCVT1
Constant value always should be 0.
Module is in timeout. All
output bits are set to 0 (watchdog).The receiver is in timeout. Checksum error.
Buffer overflowParity error or wrong data in a frame.
X not
used
0
Constant value must always be 0
2.1.1.9 Data Transfer
The status byte is used as diagnostic byte for the data communication and
indicates the status of data communication with the partner module.
Control of the multiplex connection:
In the process image of the transmitting coupler/controller, one bit is set to "1"
for the whole time. As long as this bit is "1" in the receiving
coupler/controller, further input bits can be evaluated. If the bit is "0" the
multiplex connection has been disrupted. The further bits are also 0 because of
the watchdog.
Control of the multiplex connection with acknowledge:
If the transmitting coupler/controller gets an acknowledgement from the
receiving coupler/controller, the received bit must be transferred by the
application software as an output bit to the process image. The transmission is
successful as long as the bit is "1".
Handshake:
If a serial data exchange should be made with the data exchange module, the
handshake can be made via "Toggle Bits". Therefore an input bit and an
output bit are reserved. As soon as this input bit is different from this output
bit, a request from the opposite module is made. As soon as the request is
executed the output bit is negative (toggled).
