User Manual

I/O Modules • 47
Special Modules
WAGO-I/O-SYSTEM 750
I/O Modules
Table 17: Mailbox query
Mailbox query
Byte 2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
0 0 0 1 0 0 0 0 0
1 -
2 Opcode
3 T -
4 Query parameter byte 0
… …
max. 19 Query parameter byte 15
Opcode
T
- command code of the mailbox request
- toggle bit - A mailbox request is started with a change.
In the mailbox response, bits 2
5
and 2
6
of the status byte are set. Bit 2
5
con-
firms the activated mailbox.
Bit 2
6
can be set. This indicates a general error since the modules are in con-
figuration mode and have no valid network configuration. Unused bytes of the
response are set to 0.
Table 18: Mailbox response
Mailbox response
Byte 2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
0 0 0/1 1 0 0 0 0 0
1 -
2 Opcode (mirrored)
3 T Return value
4 Response parameter byte 0
… …
max. 19 Response parameter byte 15
Opcode
T
Return value
- mirrored command code of the mailbox request
- toggle flag - A mailbox request is confirmed by a change.
- Status/error of the mailbox request
The mailbox is unmasked if there is an existing wireless connection to the lo-
cal device; this is signaled to the other party by bit 2
2
. This warns of poten-
tially aged data due to the uncovered mailbox (see Section 2.1.1.8.2.1).