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Model 2018E Operations Manual Rev Apr 2020 Page
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Event Mode
: The Signal Sequence Log records the 60 most recent events preceding the failure. An
event is defined as an instance when any AC or DC signal, except for the Watchdog input, changes
state. The monitor checks all inputs for changes in state every 33 milliseconds for the purpose of
accumulating data for this log. Data recorded: Time Prior to Fault; Status and voltage of all Greens,
Yellows, and Reds; status and voltage of all DC inputs; status and voltage of Red Enable; status and
voltage of AC Line; and status and voltage of Special Function 1 & 2.
Time Mode
: The Signal Sequence Log records the 2 seconds preceding the failure. The monitor
records all inputs every 33 milliseconds for the purpose of accumulating data for this log. Data
recorded: Time Prior to Fault; Status and voltage of all Greens, Yellows, and Reds; status and voltage
of all DC inputs; status and voltage of Red Enable; status and voltage of AC Line; and status and
voltage of Special Function 1 & 2.
2.8
DIAGNOSTICS
The Model 2018E unit incorporates a 16-bit microprocessor as the main processing unit, a 16-bit digital signal
processor (DSP), and two 8-bit microcontrollers. The main microprocessor can be upgraded via the front panel
communications port. The DSP and the two microcontrollers are flash based and can be reprogrammed in circuit.
One of the microcontrollers is dedicated to monitoring diagnostic signals from the other microcontroller, the DSP,
and the main microprocessor. This microcontroller holds the main microprocessor in the reset state until the AC
Line voltage and all supply voltages have been verified as being within operational ranges.
The monitor has an internal buzzer that stays on to indicate when the main microprocessor is not running. This
will only occur very briefly during power up, 1.5 seconds after loss of AC power, and during major diagnostic
failures.
The monitor is provided with a series of resident self-check diagnostics capabilities. When a fault is detected, the
monitor transfers the Output relay contacts to the fault condition and illuminates the front panel
DIAG FAIL
LED.
Diagnostic failures are latched in the fault condition until the unit is reset by the activation of the front panel reset
switch or activation of the Reset input. A diagnostic failure is not reset by a monitor Power Failure.
2.8.1
MEMORY
The monitor verifies all memory elements on power up or upon reset of a Diagnostics failure. A failure of any of
the memory tests will generate a diagnostics failure.
RAM Diagnostics
: Test patterns are written to every byte of RAM in the monitor. After each write a
read is performed to verify that the pattern is correct.
Program Flash Memory Diagnostics
: A checksum is calculated for the entire program in the monitor.
The calculated value is compared to a preprogrammed value stored in the Flash memory.
Configuration & Logging Flash Memory Diagnostics
: A checksum is calculated for all of the
configuration data and logging data stored in Flash memory in the monitor. The calculated value is
compared to the value that was written to Flash memory during the last power down.
The monitor continues to verify the checksums of the Program memory and the Configuration & Logging memory
during normal operation. Checksums are calculated for each type of memory at a rate of at least 1024 bytes per
second.
2.8.2
MICROPROCESSOR MONITOR
The monitor continuously checks the operation of its microprocessor. The monitoring circuit receives a signal or
logic state transition at least once every 33 milliseconds from the main microprocessor. When the signal or logic
state transition is not received for more than 50 milliseconds a diagnostics fault is generated.
2.8.3
INTERNAL VOLTAGE MONITORS
The monitor checks the voltage levels of the internal DC power supplies. The +12 volt, +5 volt, +3.3 volt, and -3.3
volt power supplies are all monitored for proper voltage levels. When any of these voltage levels is invalid for
more than programmed time a diagnostics fault is generated. These faults will not be logged by the monitor, as any
one of these voltages being invalid will immediately place the monitor in a diagnostic failure mode with the
microprocessor held in reset. This prevents any false faults or missed faults due to an internal power supply
malfunction.
2.8.4
LED DISPLAY TEST
All of the LEDs on the front panel can be illuminated by pressing the front panel reset switch or activating the
Reset input. When the reset switch is pressed or the Reset input activated, all of the LEDs will illuminate for 300
milliseconds. This allows the user to ensure that all displays are functioning correctly.
A more comprehensive test of the front panel LEDs is available through the RaeComM software. This testing will
sequence through a preprogrammed sequence of test patterns.