Fieldbus Coupler Mode; Diagnostic Functions; Local Bus Communication; Local Bus Failure Monitoring - WAGO 750 Product Manual

Functions

4.4 Diagnostic Functions

4.4.1 Local Bus Communication

Fieldbus coupler mode offers the following monitoring functions:

• Local bus failure monitoring

• Controller failure monitoring

• Power failure monitoring

The effects of the displayed statuses are described in
[} 34].
4.4.1.1 Local Bus Failure Monitoring
The SMI Master Module can be configured in such a way that a local bus watchdog moni-
tors data transmission via the local bus.
A local bus failure is diagnosed if no local bus communication occurs for 100 millisec-
onds.
For the response to a local bus failure, a delay time can be set after which the
SMI Master Module automatically moves all SMI LoVo Drives to the forced position ac-
cording to the configuration.
4.4.1.2 Controller Failure Monitoring
Failure of the programmable logic controller (PLC) is diagnosed if no level change occurs
in the corresponding bit of the extended control byte for one second.
For the response to a controller failure, a delay time can be set after which the
SMI Master Module automatically moves all SMI LoVo Drives to the forced position ac-
cording to the configuration.
Control failure monitoring is inactive after the SMI master module is reset. If the monitor-
ing of a controller failure is inactive, the drives can be operated without a functioning PLC
program via 1-button operation, e.g., during installation or maintenance of the hangings.
Control failure monitoring is not enabled again until the controller runs properly with a
PLC program and executes the FbSMI_Master function block.
You can find more information in:
8 Control and Status Bytes [} 21]
•
8 1-Button Mode [} 13]
•
8 Forced Position [} 13]
•
8 Use 1-Button Operating Mode [} 37]
•
4.4.1.3 Power Failure Monitoring
If the field supply voltage falls below the value required for proper operation of the SMI
master module, the SMI power supply switches off.
Then the SMI functions and the digital input and output cannot be used. The SMI master
module remains available on the local bus.
26 Product manual | Version: 3.0.0
SMI Master LoVo; 24 VDC
8 Diagnostics via Indicators
753-1631