Return Values Of Mailbox Commands - WAGO I/O-SYSTEM 750 Manual

6.2 Return Values of Mailbox Commands

The following standard values are defined for the return values
(MBX_RESULT) of mailbox commands:
Label
MBX_CMD_OK
MBX_CMD_GENERAL_ERROR
MBX_CMD_DENIED_UNKNOWN
MBX_CMD_OUT_OF_RANGE
MBX_CMD_INVALID_ARG
MBX_CMD_INTERNAL_ERROR
MBX_CMD_TIMEOUT
MBX_CMD_DENIED_NOT_APPLICABLE
MBX_CMD_DENIED_NOT_IMPLEMENTED
MBX_CMD_DENIED_MBX_TOO_SMALL
MBX_CMD_DENIED_BUSY
MBX_CMD_INVALID_CONFIGURATION
All mailbox commands use these return values to signal the status of the
command execution. If individual return values offer additional interpretations
for specific mailbox commands, this is explained in more detail in the descrip-
tion of the respective command.
In principle, the first return value with a mirrored mailbox command and tog-
gle bit is considered a valid response. As soon as this happens, the next mail-
box command can be executed. Many commands result in a restart of the
module. If a mailbox command that triggers a restart is not replaced by an-
other command after receiving the response, the module recognizes the unal-
tered, existing command when it restarts. The command is rejected with
MBX_CMD_DENIED_BUSY to prevent an endless loop of resets. This of-
fers the possibility of determining the successful conclusion of a reset by
monitoring change of the return value.
WAGO-I/O-SYSTEM 750
I/O Modules
Return Values of Mailbox Commands
Return Description
value
0x00 Successful execution
0x01 General error
0x02 Unknown command
0x03 Values outside of the valid range
(overrun or underrun)
0x04 False or invalid argument
0x05 Internal fault
0x06 Time overrun of the command
0x07 Prerequisites for command not ful-
filled: false operation mode, false
device role or necessary precursor
command not executed
0x08 Command reserved for later imple-
mentation
0x09 Mailbox too small for return value
0x0A Current or precursor command being
executed, no valid data is available
yet. Recommendation: call up com-
mand again after a short waiting
period.
0x0B System or network configuration is
defective
Appendix • 101