6. Configuring the Gateway
6.11.2.1. Managing Degraded Modes
Due to the number of hardware elements and software tools used, the following table shows a summary of the various degraded modes in a DeviceNet application. In this case, this application includes an LUFP9 gateway, but we will not be including either the master PLC or its scanner:
Desired behaviour
Reset
Outputs | Hold |
Stop refresh
Reset
Inputs
Hold
Event
DeviceNet PLC: | Disconnection of the | Failure of the |
| Disconnection |
| of the downstream | |||
upstream DeviceNet | LUFP9 gateway |
| ||
CPU stop or failure |
| Modbus RTU | ||
network (1) | (2) |
| ||
|
| network (1) (2) | ||
|
|
|
| |
Depending on the | “Offline options for |
|
|
|
configuration | fieldbus” = “Clear” | Depending on the configuration | ||
of the DeviceNet | “Offline options for | of the Modbus slaves | ||
master | fieldbus” = “Freeze” |
|
|
|
“Offline options for |
| |||
fieldbus” = “No Scanning” |
| |||
|
|
|
| |
|
|
| “Offline options for sub- | |
Depending on the configuration |
| network” = “Clear” | ||
|
| |||
of the DeviceNet master |
| “Offline options for sub- | ||
|
|
| network” = “Freeze” | |
|
|
|
|
(1)The “Offline options for fieldbus” and “Offline options for
(2)The behaviour desired with regard to the outputs should be directly configured on each of the Modbus slaves. In the case of drives marketed by Schneider Electric, for instance, resetting the outputs is configured by setting the NTO bit to 0 (communication control), and they are held by setting NTO to 1 (suppression of communication control).
You can also read the user manuals for your master and your DeviceNet scanner to obtain further details about how to process degraded modes.
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