AADvance Safety Manual - Tuv-fs.com

AADvance Safety ManualFor a digital output module, the process safety time represents the period of awatchdog timer that specifies the length of time the controller will allow the module torun without receiving updates from the application. If the module runs beyond this timewithout receiving any updates, it enters its shutdown state (see below). The defaultprocess safety time is 2500ms.Input Module Safety FunctionsI/O input module safety functionsAn I/O input module is classified as safety critical and is designed to SIL3 level as asingle fail safe module. The input modules offer 8 or 16 isolated channels and reportsinput voltage levels to the processor, for the analogue input variant the module willconvert the field current into a voltage. Input values are updated by the workbench atleast once per application cycle. The same hardware is used for the 24Vdc digital inputmodules and the 4- 20mA analogue input module.The input module will operate in a SIL2 or SIL3 configuration for energize to action andde-energize to trip applications The module provides the following isolation: channel to channel galvanic isolation galvanic isolation between channels and the communication signals galvanic isolation between channels and powerReactions to faults in the input modulesWhen an input channel is not capable of reporting a voltage within a safety accuracyspecification of 1% of the full scale measurement range, then the module returns safevalues to the processor. Signals go to a safe state if the module scan time exceeds thePST. All I/O modules provide front panel indications, store fault codes in the fault logand can also report via the workbench application variables. The following statusinformation is provided: module presence module health and status channel health and status field faults an echo of the front panel indicators for each moduleNote: The HART input information can be used to provide additional diagnosticcoverage for the I/O loop. You have to use the 4 - 20mA current loop as the primarysafety data.Availability of input modules5-20 Document number 553630 Issue 7: February 2010