WAGO-I/O-SYSTEM 750
Function Description 33
750-658 CAN Gateway
Manual
Version 1.2.1, valid from FW/HW-Version 01/01
"Remote Transmission Request" (RTR) Setting
The "Remote Transmission Request" bit can used to set whether the mapped
CAN output frame involves a so-called "remote request" or a data frame.
"Data Length Code" (DLC) Setting
The "Data Length Code" (DLC) can be used to specify how many user data bytes
there should be in the CAN telegram.
The user data bytes do not have to match the mapped bytes on the process
image in terms of quantity. A fixed value can be specified for all non-mapped
data bytes.
Fixed values can be specified for data storage areas that have been defined in
the DLC, but not mapped variably in the process image. These values are then
automatically copied to the user data when a telegram in the output direction is
generated.
5.1.3.2.2 "Send on request" Setting
In this setting, CAN telegrams are send via the so-called "toggle byte" in the
process image. Send groups can be assigned to telegrams to be sent.
If one or more bits are inverted in the toggle byte, the respective send groups are
affected. All assigned telegrams are created and sent.
Table 16: Toggle Byte
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Toggle byte
Group 8 Group 7 Group 6 Group 5 Group 4 Group 3 Group 2 Group 1
The I/O module then confirms transmission by inverting the associated bit of the
toggle byte in the process image of the input.
If several send groups are selected, they are sent one after the other: Group 1
has the highest send priority, Group 8 has the lowest.
5.1.3.2.3 "Send on change" Setting
If this setting is enabled, the CAN telegram is sent when a mapped byte has
been sent. The mapped and fixed values are applied.
5.1.3.2.4 "Cycle Time" Setting
A cycle time can be set for each CAN telegram to sent. The telegram is then
created and sent repeatedly by the I/O module. The time interval between two
transmissions is the cycle time. It can also be a telegram that contained no data
from the process image of the output, rather fixed values only.