Table 32: Mailbox Request; Table 33: Mailbox Response - WAGO I/O-SYSTEM 750 Manual

56 Process Image

Table 32: Mailbox request

Byte
0
1
2
3
4
...
max. 19
*
Command code of the Mailbox job
**
Toggle bit: The Mailbox job is started when there is a change.
Interpretation only when changing the opcode or toggle bit!
The content of the Mailbox is only interpreted by the 750-644 I/O module when
the opcode changes or the toggle bit is inverted. A change in the parameters does
not result in processing of the mailbox content!
Ensure consistency of the parameters!
If a request includes parameters, they must be written to the output process image
with the associated opcode and toggle bit at the same time. If the parameters only
occupy part of the area of the process image overlaid by the Mailbox, all
unoccupied bytes must be overwritten with the value 0.
There is a response when the value of the opcode and bit 7 of the toggle byte in
the PII matches those in the PII. A PLC application, for example, can evaluate the
entire response. The return code plays a specific role here, for example, because
the parameter data of the response can be invalid when certain errors arise.

Table 33: Mailbox response

Byte
0
1
2
3
4
...
max. 19
*
Command code of the Mailbox job
**
Toggle bit: The Mailbox job is started when there is a change.
***
Status/error of the Mailbox job
The processing time in the 750-644 I/O module may require several bus cycles.
Some specific commands trigger a longer process (e.g. scan for devices within
range). For such commands, the response of the 750-644 I/O module confirms
that the process has begun. The results of longer lasting processes can be queried
after completion of the respective process by other commands.
7 6 5
2 2 2
0 0 1
**
T
7 6 5
2 2 2
0 0/1 1
**
T
750-644 Bluetooth
Mailbox request
4 3
2 2
0 0
-
*
Opcode
-
Request Parameter byte 0
...
Request Parameter byte 15
Mailbox response
4 3
2 2
0 0
-
*
Opcode (mirrored)
***
Return value
Response Parameter byte 0
...
Response Parameter byte 15
Version 2.0.0, valid from FW/HW Version 03/03
WAGO-I/O-SYSTEM 750
®
RF-Transceiver
2 1 0
2 2 2
0 0 0
2 1 0
2 2 2
0 0 0
Manual