module is not communicating with the operating system. Replace the VI-
Gen Module.
6.3.1.4 Binary Inputs and Battery Simulator
If all the items external of the Timer assembly are in proper order, then the problem exists
within the Binary Input assembly itself.
Some basic troubleshooting can pinpoint problems to the approximate cause.
Basic troubleshooting is as follows:
1.
Timer does not stop:
Jumper the appropriate Binary Input terminals manually. If LED above the
selected input lights, check Timer Setup screen to verify that the selected binary
input is properly setup as a Timer Stop post. Check Timer Stop settings as N.O.
(Normally Open) and Latch On. If LED does not light up, the TCM backplane will
need to be repaired or replaced.
2.
Counting errors:
AC applied or removed Start/Stop signals can create, what appears to be poor
repeatability, an inaccuracy or a malfunction in the Timer. The lower the voltage
level, the more serious the "error" will be. What appears to be an error, however,
is actually a variation in the point on the sine wave at which the voltage is great
enough to cause the gate circuit to operate. If the circuit used for the timing test
has a low AC voltage and the point at which the contact in the test circuit opens
or closes, is at or close to zero on the sine wave, the period of time before the
voltage level will be high enough to trigger the gate circuit can be as much as 4
milliseconds. The total timing variation can be as much as 8 milliseconds. The
shorter the duration of the timing test, the more significant the variation becomes.
Therefore, if small timing variations would present a problem, it is recommended
that an AC voltage of 115 volts or above or a DC voltage be used for voltage
applied/removed test selections.
When the MPRT Timer calibration is being tested, the AC voltage variable is
often overlooked. This is particularly true when the Timer is compared to a
counter and the two are triggered simultaneously with an electronic switch. For
best results, a DC voltage should be used to eliminate the variable. If testing the
AC voltage Start/Stop characteristics is desired, then the Start/Stop signal must
be triggered at the same point on the sine wave to assure that the gate signal will
be repeatable. Ideally, the signal should be at a point near peak in the positive
direction. In addition, the specified rms AC voltage values for the various
Start/Stop control selections must be adhered to.
Another source of apparent "error" can be the programmable de-bounce feature.
If using electro-mechanical contacts for starting and stopping the Timer, and if
those contacts have a tendency to bounce, there could be a difference between
an external standard timer and the MPRT Timer, depending on the programmed
de-bounce period. To determine the programmed value, look at the Timer Setup
Screen and see what the De-bounce setting value is.
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