Honeywell UDC2500 ユーザーズマニュアル

The UDC2500 performs ongoing background tests to verify data and memory integrity.  
If there is a malfunction, a diagnostic message will be displayed (blinking) in the lower 
display. 

In the case of simultaneous malfunctions, the messages will appear in sequence in the 
lower display.  Table 7-3 lists these background tests, the reason for their failure, and 
how to correct the problem. 

Diagnostic messages may be suppressed (stop the blinking) by pressing the RUN/HOLD 
key. The messages will still be available for viewing by pressing the LOWER 
DISPLAY key. 

Unable to write to non-volatile 
memory. Anytime you change a 
parameter and it is not accepted, you 
will see E FAIL. 

1.  Check the accuracy of the parameter and re-

enter. 

2.  Try to change something in configuration. 

3.  Run through Read STATUS tests to re-write 

to EEPROM. 

This error message shows whenever 
the controller goes into a failsafe 
mode of operation. This will happen if: 
 

•  RAM test failed 

 

•  Configuration test failed 

 

•  Calibration test failed 

 

•  Burnout configured for none 

and the input failed. 

1.  Run through STATUS check to determine the 

reason for the failure. 

2. Press the SET UP key until STATUS appears 

in the lower display. 

3. Press the FUNCTION key to see whether the 

tests pass or fail, then run through the 
STATUS codes a second time to see if the 
error cleared. 

Input 1 out of range. The process 
input is outside the range limits. 

 

1.  Make sure the range and actuation are 

configured properly. 

2.  Check the input source. 

3.  Restore the factory calibration. (See 

 

4.  Field calibrate. See Section 5 - Input 

 

Two consecutive failures of input 1 
integration; i.e., cannot make analog 
to digital conversion. This will happen 
if: 
 

•  Upscale or Downscale 

burnout is selected and the 
input is open 

 

•  Input not configured correctly 

for the sensor being used 

1.  Make sure the actuation is configured 

correctly. See Section 3 - Configuration. 

2.  Make sure the input is correct and that it has 

not burned-out (opened). 

3.  Check for gross over-ranging with a 

multimeter.  

4.  Restore factory calibration. See Subsection