Omron CRT1 - 10-2008 Operation Manual page 523

Troubleshooting
Model
Analog I/O Slave The disconnection display
Units (Inputs) does not clear.
No disconnection display.
The conversion cycle is too
long.
Analog I/O Slave The expected value is not held
Units (Outputs) when communications errors
occur.
Temperature Input The 1/100 Display Mode has
Units been set, but the display reads
0.
The temperature difference
detected between inputs is not
rising properly.
The temperature range
counter is not counting even
though the temperature value
is set as the count condition.
The Top/Valley Count Over
Flag will not go ON.
The comparator does not oper-
ate as expected even though
the function and hysteresis
value have been set.
500
Problem
• The Sensor is disconnected.
• Disconnection is not dis-
played for ranges other than 1
to 5 V and 4 to 20 mA.
• The setting of the number of
AD conversion points is on
the maximum (4 points).
• The processing time gets
longer each time a function is
added.
• The output value that is set
for communications errors is
incorrect.
The allocated word is the one
word in the normal display
area.
• Data other than the tempera-
ture input value is allocated
for Analog Data 2.
• The temperature difference
display is always a 1/100 dis-
play.
The comparator is not enabled. Enable the comparator. (The
• The top/valley hold function is
not enabled.
• The hysteresis setting is too
high.
• The hysteresis setting is 0.
• The temperature display set-
ting has been switched (°C to
°F or vice versa).
• The decimal point position-
was read incorrectly.
Cause Possible correction
• Restore the Sensor connec-
tion.
• Check the connected Sensor
and input type again.
---
• Reduce the number of points
if some inputs are unneces-
sary, and execute conversion
again.
• Delete any unused functions,
and execute conversion
again.
• Check the output setting for
communications errors.
Either change the default con-
nection path to the 1/100 dis-
play area or select a
connection path in the Master
Unit for the 1/100 display area.
Allocate the temperature input
value for analog data 2.
power must be turned OFF
and then ON again.)
• Enable the top/valley hold
function. (The power must be
turned OFF and then ON
again.)
• Adjust the hysteresis setting.
Check the decimal point posi-
tion and °C/°F display for the
input type and display mode.
If these settings have been
changed during operation,
check the comparator and hys-
teresis settings and correct if
necessary.
Section 12-2