92 Appendix
WAGO-I/O-SYSTEM 750
750-658 CAN Gateway
Manual
Version 1.2.1, valid from FW/HW-Version 01/01
12.2 Protocols Supported by Mailbox 2.0
Messages can be exchanged between different devices using the Mailbox 2.0
transfer procedure. Messages that are exchanged can be read by the
communication partner only when they are structured in line with a known
protocol. The Mailbox 2.0 transfer procedure uses the field "Protocol ID" of the
expanded header to identify the protocol being used.
Each of the transmitted messages consists of the header and a protocol data unit
(PDU) whose length and structure are based on the specific protocol.
The I/O module supports the following protocols:
Table 39: Protocols Supported by Mailbox 2.0
Protocol ID Protocol Name Description
0x80
Parameter
access
Protocol for reading and writing of parameters
0x81
Diagnostics
Protocol for transfer of diagnostics messages
12.2.1 Protocol 0x80 (Parameter Access)
This protocol implements confirmed services for reading, writing, storing and
restoring of parameters.
Table 40: Protocol 0x80, Description of Services
Service
Description
Read
Reading of a parameter addressed by a table and register
number.
Write
Writing of a parameter addressed by a table and a register
number. Written values are initially saved only to a volatile
memory. The service "Save" must be used to save
parameters to a non-volatile memory.
Save
Save all parameters to a non-volatile memory.
Restore
Restore factory default settings. All current parameter values
will be overwritten.
Set password
You must perform this service one time before any
parameters can be written.
The structure and length of the PDUs for this protocol differ for request and reply
messages.