Operator gets the following warnings while operating a temperature controller (Figure 1):
TempController 2-3-Output—Temperature Controller returned an error.
TempController 2-3-Output—Please verify Setpoint range limits on Temperature Controller.
Figure 1 – Application log warning messages
“Here is another thought: The controller that I was demonstrating to you last week began giving me the same issue. In fact, after I switched channel 1 (Upper Zone) over to Fahrenheit, and then back again to Celsius, it became chronic. Would only indicate “Temperature Controller Setpoint Range Error”. So, what I did was to go into the ‘PV’ menu, and changed lower range value to -1 ( C ), and upper range value to 1251 ( C ). Also changed setpoint upper/lower range limits to -1 and 1251. I left 793 Station Manager limits at 0 and 1250. That was an hour and 15 minutes ago, and it hasn’t given me an error yet.
I think that the real issue is that 793 range settings need to fit inside the controller limits, and not exceed by any amount. My guess is that even if I set the Eurotherm up for -1 and 1380, it would still work OK with 793 set at 0 and 1250. Station Manager limits should be a sub-set of the controller’s range. When we try to set them exactly the same, it appears that we are having some kind of error due to math, precision, or resolution. ”
You need to set the rnGL (input range low) and rnGH (input range high) to outside the Station Manager station setup min/max range (Figure 1).
Figure 1 – Station Manager’s Min/Max temperature range
They are under the Eurotherm’s menu settings Config > PU (Figure 2).
Figure 2 – rnGL and rnGH Eurotherm 2404/2408 menu settings
For example, if the Station Manager calibrated Min/Max range is 0℃ to 1250℃ the Eurotherm’s rnGL value should be -1℃ and rnGH should be 1251℃.
Likewise, the SP L and SP H are found under the menu settings below (Figure 3).
Figure 3- SP L and SP H Eurotherm 2404/2408 menu settings