Table Of Contents

Analog Input Configurations (NI 9351 Only)

Version:
    Last Modified: May 15, 2018

    spd-note-note
    Note  

    Discrepancy fault and discrepancy warning are dependent on the measured current. For a discrepancy fault or warning to occur, the faulted channel must have a current delta with respect to the other channel(s) greater than the configured discrepancy current.

    Table 1. Single Input
    Condition Resulting Current Region Diagnostic Fault
    Short to ground Low low
    Current exceeds specifications High high Overcurrent fault
    Open circuit Low low
    Incorrect sensor output Current region depends on the current input from the faulted sensor.
    Table 2. Dual Input (1oo2)
    Condition Resulting Current Region Diagnostic Fault(s)
    Short to ground (one channel) Low low Discrepancy fault
    Short to ground (both channels) Low low
    Current exceeds specifications (one channel) High high unless the other channel is low low. Overcurrent fault and discrepancy fault
    Current exceeds specifications (both channels) High high Overcurrent fault
    Open circuit (one channel) Low low Discrepancy fault
    Open circuit (both channels) Low low
    Incorrect sensor output (one channel or both channels) Current region depends on module FPGA voting outcome. Discrepancy fault
    Table 3. Triple Input (2oo3)
    Condition Resulting Current Region Diagnostic Fault(s)
    Short to ground (one channel) Current region depends on module FPGA voting outcome. Module FPGA assigns low low current region to faulted channel. Discrepancy warning
    Short to ground (two channels) Low low Discrepancy warning
    Short to ground (all channels) Low low
    Current exceeds specifications (one channel) Current region depends on module FPGA voting outcome. Module FPGA assigns high high current region to faulted channel. Discrepancy warning
    Current exceeds specifications (two channels) High high Overcurrent fault and discrepancy warning
    Current exceeds specifications (all channels) High high Overcurrent fault
    Open circuit (one channel) Current region depends on module FPGA voting outcome. Module FPGA assigns low low current region to faulted channel. Discrepancy warning
    Open circuit (two channels) Low low Discrepancy warning
    Open circuit (all channels) Low low
    Incorrect sensor output (one channel) Current region depends on module FPGA voting outcome. Discrepancy warning
    Incorrect sensor output (two channels or all channels) Current region depends on module FPGA voting outcome. Discrepancy fault or discrepancy warning

    Recently Viewed Topics