WAGO-I/O-SYSTEM 750
Process Image 37
750-658 CAN Gateway
Manual
Version 1.2.1, valid from FW/HW-Version 01/01
6.1
Process Image in "Sniffer" Operating Mode
The CAN user data range on the process image is symmetrical for both data
directions.
Figure 10: Process Image in "Sniffer" Mode
6.1.1
Mailbox
Modules with mailbox functionality have an acyclic communication channel
(mailbox) in the process image. The "Mailbox 2.0" (referred to below as
"mailbox") transmission method is the basis.
If the Mailbox is active (control byte, bit 7 = 0), it is used to transfer configuration,
parameterization and diagnostic data. Bytes 1 to 6 of the local process image are
used by default. Additional information about the "Mailbox 2.0 Transmission
Method" is available in the respective section in the appendix.
6.1.2
CAN User Data Range
The CAN user data range is a fixed component of the "Sniffer" and "Transparent"
operating modes (see respective section). CAN telegrams are transmitted via the
"Mailbox 2.0" communication mechanism. The mechanism supports the following
two types of telegrams:
•
"2.0A Standard Frame"
•
"2.0B Extended Frame"