Allen-Bradley GuardPLC 1753, Справочник по безопасности

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Publication 1753-RM002C-EN-P - September 2008 61
GuardPLC DeviceNet Safety Scanner Chapter 5
Error Reaction
This section describes how the module reacts to HSP and DeviceNet
connection losses and diagnostic test failure.
HSP Connection Loss
On the loss of HSP, all producing DeviceNet safety connections are
transitioned to the Idle mode, resulting in the end device transitioning
to its safety state. All standard DeviceNet I/O connections are likewise
transitioned to Idle mode, resulting in the standard nodes transitioning
to their Idle state. When the HSP connection is restored, the
DeviceNet safety and standard connections are returned to Run mode
with normal data production.
The safety scanner closes the HSP connection whenever either an HSP
error occurs or the safety scanner diagnostic reports an error.
Individual DeviceNet safety or standard connection errors do not
cause the HSP connection to close and the associated status bit is set
to one.
DeviceNet Connection Loss
On the loss of a DeviceNet safety or standard connection, the data
associated with connections for which the scanner is the consumer,
are set to zero and the associated status bit is set to one. The scanner
automatically attempts to re-establish any lost DeviceNet connections
for which it is the originator. When the connection is recovered, the
data is set to the values received from the producing node and the
status bit is cleared.
When the safety scanner enters Configuration mode, all the DeviceNet
connections are terminated and eliminated. The High-speed Safety
Protocol connection is terminated. To restore connections, download
and verify a new configuration.
Failure of Diagnostic Tests
If a diagnostic test fails, all application processing is stopped and
High-speed Protocol, DeviceNet safety, and standard I/O connections
are terminated.
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