Table Of Contents

Test Pulses

Version:
    Last Modified: September 6, 2017

    You can configure internal or external test pulses on all digital signals. Test pulses verify that a line can be de-energized or driven to a safe state.

    • For outputs with test pulses, DOn is available to use in the state machine diagram. The User Program will return test pulse faults on DOn.TestPulseFault.
    • For inputs with test pulses, DOn is reserved and is not available to use in state machine diagram. The User Program will return test pulse faults on DIn.TestPulseFault.
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    Test pulses always pulse low.

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    Dual input and dual output configurations with test pulses are staggered to monitor for channel to channel shorts.

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    The User Program runs both readback diagnostics and test pulse diagnostics when you configure test pulses. Readback faults and test pulse faults report as a single event in the User Program. If you configure a channel with DIn.TestPulseFault or DOn.TestPulseFault, a test pulse fault or a readback fault would trigger a response. Scan Interface reports readback faults and test pulse faults as unique events. Scan Interface will report whether a readback fault or a test pulse fault triggered that response.

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    Make sure test pulse width does not cause the final element or safety actuator to switch off.

    You can use test pulse faults in two ways:

    • You can check the Fail-safe box for DIn.TestPulseFault or DOn.TestPulseFault. If a test pulse fault occurs, the module will go into Fail-safe Mode.
    • You can use DIn.TestPulseFault or DOn.TestPulseFault in transition logic on the State Machine Diagram. If a test pulse fault occurs, the User Program will transition to a user-configured state.

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