2010 Construction and Material Specifications - Ohio Department of ...

733.03
REMAINS LATCHED, even through a power fail/recovery, until a RESET is
issued by the front panel reset switch, or by the external test reset line.
(b) Display the status of the Green, Yellow, and Red
inputs of all channels, at the time the fault was latched. Ensure that a power loss
does not affect the retention of this data. An acceptable alternative is to save status
of all channels in memory and only display the latched fault.
(7) Insertion/Removal of Unit. Ensure that it is possible to
insert and remove the Monitor while the cabinet is energized without placing the
cabinet into Flash operation provided that: The cabinet door remains open and the
reset switch is held depressed while the unit is being inserted or removed. Any
momentary disruption of field signal indications is less than 500 ms.
(8) Microprocessor Use. If a microprocessor is used in the
Monitor design, ensure that its program is written so that:
(a) Integrity tests are performed periodically on each
memory cell of each memory device, relevant to each device type.
(b) Hardware external to the microprocessor circuits is
employed to constantly sense proper microprocessor operation.
(c) The Monitor reverts to a FAILED state if a fault is
detected with the microprocessor or during integrity tests.
(9) Front Panel Indicators. Ensure that the Monitor has
red/yellow/green indicators for channel inputs and indicators to provide status and
failure detection information. Furnish a GREEN AC POWER indicator. Ensure
that all indicators are clearly readable in direct sunlight. Arrange and label the
indicators as shown below:
(a) AC POWER. Illuminates when the incoming AC
Line Voltage exceeds 103 ± 2V ac, and FLASHES during FAULT RELAY
OPERATION.
(b) VDC FAIL. Illuminates when the Monitor has
detected a 24VDC failure.
condition is detected.
(c) CONFLICT. Illuminates when a conflicting signal
(d) WDT ERROR. Illuminates when a Watchdog error
is detected. Do not provide a switch or similar device to disable WDT monitoring.
(e) PC AJAR. Illuminates when the Conflict Program
Card is removed or is not properly seated in its connector.
Monitor failure.
(f) MON FAIL. Illuminates to indicate an internal
(g) RED FAIL. Illuminates when the Monitor detects
that there is no active output on any of the field outputs that comprise a monitored
channel. Ensure that the failed channels are displayed on the corresponding
channel indicators. If for any reason red fail is not enabled, ensure that the red fail
indicator light flashes at approximately 2hertz.
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