Danfoss MCB 152 Operating Instructions Manual
Also see for VLT series: Service manualInstallation guideOperating instructionsService manualInstallation guide
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Contents
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130BC316.10Input SignalDI1/DI2D1 x AD1 x BDiscrepancy timeSafety functionActiveInactiveIllustration 3.3 Discrepancy Time3.2.6 Stable Signal and Safety DevicesThe safety option normally responds immediately to signalchanges at its safe inputs DI1 or DI2. This response is notrequired in the following cases:• When interconnecting the safe input of theoption with an electromechanical sensor, contactbounce may result in signal changes, to whichthe option can respond.• Several control modules test their safe outputsusing test pulse patterns (on/off tests), to identifyerrors due to either short- or cross- circuiting.When interconnecting the safe input of theoption with a safe output of a control module,the option can respond to these test signals.A signal change during a test pulse pattern usually lasts 1ms.Under stable signal time, short pulses, which can lead tosafety functions being incorrectly activated, can be filtered.NOTICEThe stable signal time extends the safety optionresponse time. The safety option only activates thesafety function after the response time has expired.If the signal to the input on safety option is not stable, theoption responds with an external error after the stablesignal time expires.Definition of a stable signalFollowing a change to the DI input signals, the optiontriggers an internal monitoring time. Use 42-23 StableSignal Time to select the appropriate stable signal time. Astable signal is a high or a low signal state, which lasts forthe time defined in 42-23 Stable Signal Time.Input Signal130BC317.10DI1/DI2Safety functionActiveInactiveTest pulse patternStable signal time Stable signal timeIllustration 3.4 Filter for Suppressing Temporary SignalChangesFunctions Safety Option MCB 15212 Danfoss A/S © 10/2014 All rights reserved. MG37F10233 |
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