Honeywell UDC2500 manual Controller Failure Symptoms, Other symptoms

Troubleshooting/Service

7.6 Controller Failure Symptoms

Introduction

In addition to the error message prompts, there are failure symptoms that can be identified by noting how the controller displays and indicators are reacting.

Symptoms

Compare your symptoms with those shown in Table 7-4.

Table 7-4 Controller Failure Symptoms

Upper	Lower	Indicators	Controller	Probable	Trouble-
Display	Display		Output	Cause	shooting
					Procedure
Upper	Lower	Indicators	Controller	Probable	Trouble-
Display	Display		Output	Cause	shooting
					Procedure
Blank	Blank	Off	None	Power Failure	1
OK		OK		Current	2
				Proportional Output
	Displayed		Controller
OK		OK		Three Position	3
	Output		Output	Step Control
	disagrees		disagrees	Output
	with Controller		with Displayed
OK	Output	OK	Output	Time Proportional	4
				Output
OK		OK		Current/Time	5
				Proportional Output
OK	OK	OK	External Alarm	Malfunction in	6
			function does	alarm output
			not operate
			properly
Display does not change when a key is pressed				Keyboard	7
				Malfunction
Controller fails to go into “Slave” operation during communications				Communications	8
				Failure
OK	Displayed	OK	Controller	Auxiliary Output	9
	Output		Auxiliary Output
	disagrees with		disagrees
	Auxiliary Output		with Displayed
			Auxiliary Output

Other symptoms

If a set of symptoms or prompts other than the one you started with appears while troubleshooting, re-evaluate the symptoms. This may lead to a different troubleshooting procedure.

164 UDC2500 Universal Digital Controller Product Manual 4/07