TMR and dual system configurations have automatic voting comparison diagnostics. This diagnostic provides random failure detection. The system and the voting diagnostics can be tested through the field device test procedure if field device test procedures include the following, and the alarm system has been checked to verify that no comparison diagnostics have been generated by the test.
For each safety loop when power (or the communications cable) is removed from one I/O pack in a hardware fault tolerant channel, the comparison diagnostic should indicate a fault. When power that exceeds the hardware fault tolerance is removed from I/O packs, the system fails to its configured safe state, also for:
YAIC: Each analog sensor should be separately tested, one sensor at a time. Each test, if practicable, should range the sensor beyond the normal range of operation within the upper and lower limits of the sensors detectable range. Each output is tested when the output is ranged through a full range transition required to test the field device. When power (or the communications cable) is removed from one I/O pack in a hardware fault tolerant channel, the system should maintain the required output.
YDIA: Each sensor should be tested causing a logical transition on the controller.
YDOA: Stimulate the safety function such that the output makes a transition. When power (or the communications cable) is removed from one I/O pack in a hardware fault tolerant channel, the system should maintain the required output. Any output failures generate an error indication.
YHRA: Each analog sensor connected to an input should be tested separately. Each output is tested when the output is ranged through a full scale transition required to test the field device. The YHRA is a simplex only board, fault detection and failure modes are tested per the 61511 certified application code.
YTCC: Thermocouple inputs may be tested in place if an independent reference temperature is available to compare. Open TC detection can be tested by disconnecting one lead per TC at the terminal board screws. The cold junction temperature is tested by checking the temperature with the ToolboxST Cold Junction tab.
YVIB: Each sensor connected to an input should be separately tested, one sensor at a time (VibProx, VibProx-KPH,VibSiesmic, PosProx). Each test (if practicable) should range the sensor beyond the normal range of operation within the upper and lower limits of the sensors detectable range. Key Phasor* input accuracy can be tested in place if a reference speed is available to compare. When power (or the communications cable) is removed from one I/O pack in a hardware fault tolerant channel, the system should maintain the required output.
YPRO: Speed inputs are tested when input signals are varied and compared to the reference signal. E-Stop and contact input interlocks are tested when actuated and ETRs are observed to drop out. When power (or the communications cable) is removed from one I/O pack in a hardware fault tolerant channel, the system should maintain the required output.
YSIL: A feature enhanced version of the YPRO that includes Speed Inputs, E-Stop, ETR's, provisions for contact inputs, relay outputs, thermocouple inputs, and flame detectors.
YTUR: Speed inputs are tested when input signals are varied and compared to the reference signal. Flame detector(Gieger-Muller) inputs are tested when presence of flame is observed. E-Stop input is tested when actuated and PTRs are observed to drop out. When power (or the communications cable) is removed from one I/O pack in a hardware fault tolerant channel, the system should maintain the required output.