ABB Triguard SC300E Safety Manual

Also see for Triguard SC300E: User manual

Contents

ABB Triguard SC300E Safety Manual Manual pdf 19 page image

Issue 5 - September 2006 Page 19 of 653.5 Diagnostic ConfigurationThe Triguard SC300E Fault Tolerant Safety PLC provides an extremely high level of hardwarefault diagnostics. All diagnostic errors found initiate a change in state in the Fault Register. It istherefore mandatory that the Fault Call Module be activated in one of the diagnostic networks toprovide access to system level diagnostics.3.5.1 Diagnostic Message GenerationThe activation of the Fault Call when an error is found must be used to provide a diagnosticmaintenance message to the operator, to allow repair actions to be taken. Diagnosticmessages can be provided in a number of acceptable formats, eg Printed Messages, OperatorAlarms, Diagnostic LED Alarms and Diagnostic Alarm Mimics on Operator Stations. A minimumof one digital output must be configured to give a fail-safe output to ensure that theoperator/maintenance is made aware that there is a problem with the system that needs action.A combination of methods is usually utilised to provide the maintainer with diagnosticinformation and the operator with alarm and status information.For information on the Triguard error bits refer to the Triguard User Help facility.3.5.2 Printed MessagesThe triplicated database can contain a number of printed messages that can be triggered byevents such as diagnostic alarms and plant alarms. The printed messages database isprepared by a Systems Designer linking the discrete, to which the event is to be referenced, tothe alarm diagnostic message to be printed. The message database is compiled and loaded aspart of the load module.3.5.3 Diagnostic LED'sAs all diagnostic information exists as discretes within the database, these can be utilised todrive outputs directly to light panel mounted LED's for example. It is also practical to utilise theDual Serial Multiplexer System TM117DMX to drive LED's for alarms. The TM117DMX is notapproved for safety critical signals.3.5.4 Display System DiagnosticsIn systems that are provided with Operator Workstations for graphical alarm information (suchas TriCommand), diagnostic display mimics can be generated allowing VDU diagnostic alarmdisplays of the diagnostic discretes. These operator stations are not normally fault tolerant andas such are not considered as part of the safety system.3.5.5 Maintenance WorkstationsThe Password Protected Maintenance Workstation is used to display the diagnostic and historytables in a snapshot manner, it also provides detailed diagnostic information on I/O module andI/O channel errors. During operation it is not necessary to have the maintenance workstationcontinuously attached to an operating Triguard SC300E PLC. When maintenance actions havebeen completed the TriBuild Workstation should be disconnected from the operating SC300EPLC.3.5.6 Error Flags and Automatic Diagnostic ActionsThe diagnostics available through the TriBuild Workstation are extremely comprehensive anddetailed down to channel level. A summary of these diagnostics is made available to the userby the use of the "Fault Call", which provides a voted set of diagnostic flags.