Watlow Series 94 - Manual (Page 24)

5 . 2 ■ A l a r m s a n d E r r o r s W a t l o w S e r i e s 9 4
Alarms and Errors
Error Code Messages
Three dashes [`---] in the upper display indicate a Series 94 error. The
error code is visible in the lower display.
[`Er2] - Sensor underrange error (applies only to RTD units)
The sensor input generated a value lower than the allowable signal range, or
the A/D circuitry malfunctioned. Enter a valid input. Make sure the
[``In]
Input parameter (Setup Menu) and the DIP switch settings both match your
sensor. Refer to Table 4.5b on page 4.5 for the appropriate input type and
range.
[`Er4] - Configuration error
The controller’s microprocessor is faulty; call the factory.
[`Er5] - Non volatile checksum error
The nonvolatile memory checksum discovered a checksum error. Unless a
momentary power interruption occurred while the controller was storing
data, the nonvolatile memory is bad. Call the factory.
[`Er6] - A/D underflow error
The A/D circuit is underrange. An open or reversed polarity sensor is the
most likely cause. Check the sensor; if the connection is good and functions
properly, call the factory. The A/D underrange voltage is too low to convert an
A/D signal. Make sure the
[``In] Input parameter matches your sensor and
DIP switches are set accordingly.
[`Er7] - A/D overflow error
The A/D circuit is overrange. An open or reversed polarity sensor is the most
likely cause. Check the sensor; if the connection is good, and the sensor func-
tions properly, call the factory. The A/D overrange voltage is too high to con-
vert an A/D signal. Make sure the
[``In] Input parameter (Setup Menu)
matches your sensor and DIP switches are set accordingly.
Error Code Actions
[`Er2], [`Er6], [`Er7]
To clear a corrected error, press the ‰Advance key to clear the input error
code. Wait for the upper display to change from showing
[`---] to showing
the process temperature. The Limit message [`Err] will appear. Then
press the RESET key to clear/reset the error latched outputs. There may be
a 30 second delay from when the ‰Advance key is pressed.
[`Er4] and [`Er5] result in these conditions:
• Both outputs will turn off.
• The alarm output, if present, will be in an alarm state (de-energized
with the indicator light on).
• The upper display indicates the process value.
• The lower display indicates the error code.
• All keys are inactive.
• All Setup Menu parameters return to default values.
• The above conditions occur regardless of the value of
[`LOC], or the
presence of the Setup or Calibration Menus.
To clear a corrected error cycle power to the controller or press the RESET
key.
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CAUTION:
Electrical noise or a
noise event, vibration
or excess environ-
mental moisture or
temperature may
cause Series 94
errors to occur. If the
cause of an error is
not otherwise appar-
ent, check for these.
Figure 5.2 -
Error Code Message. RESET
LIMIT 94