Post by crdvis16 on Sept 19, 2024 14:08:43 GMT -5
Hello- I've inherited a temperature control system that has LS218, 340, and 336s all controlled by a rather comprehensive LabVIEW program. In testing this system I am running into an issue I don't quite understand.
Upon startup this system configures these lakeshore units in many ways, including attempting to set the heater range for the LS340s to 5 (100W) and then immediately reads that setting back again to verify the change took. However, the reading that comes back is always 0 (Off). I believe this could occur if the heater range limit is set to 0 (Off) but I have checked and the limit is set to 5 (100W).
I have since tried to get the heater range to properly show 5 (100W) by using the LS340 front panel manually (rather than through the LabVIEW application) but still with no luck. My steps were roughly:
1) select heater loop 1
2) in the 'Control Setup' menu:
i) Enable -> ON
ii) Ctrl Mode -> Open Loop
iii) Max Range -> 100W
3) back on the main heater loop 1 menu, Manual Output -> 10% (or any other value other than 0%)
4) Heater Range -> 5
At step 4 it just immediately shows 'Heat 0% of OFF' rather than what I would expect as 'Heat 10% of 100W' or something along those lines.
One thing I don't quite understand is that when I set the Manual Output to, say, 10% the 10% value shows up over to the right of the PID settings as MOut + 10% (as if it's being added to the PID values in manual PID mode even though I selected Open Loop mode?).
Another possible issue I should mention is that I don't actually have any heaters or sensors connected to any of my lakeshore units yet. In other words, all of my feedback sensors are reading 'T. Over' and there is no resistor connected to the heater loop. Would that stop the LS340 from being able to change the heater range and correctly read it back as 5 rather than 0?
Any advice is welcome and thank you in advance!
~Clinton Davis
Upon startup this system configures these lakeshore units in many ways, including attempting to set the heater range for the LS340s to 5 (100W) and then immediately reads that setting back again to verify the change took. However, the reading that comes back is always 0 (Off). I believe this could occur if the heater range limit is set to 0 (Off) but I have checked and the limit is set to 5 (100W).
I have since tried to get the heater range to properly show 5 (100W) by using the LS340 front panel manually (rather than through the LabVIEW application) but still with no luck. My steps were roughly:
1) select heater loop 1
2) in the 'Control Setup' menu:
i) Enable -> ON
ii) Ctrl Mode -> Open Loop
iii) Max Range -> 100W
3) back on the main heater loop 1 menu, Manual Output -> 10% (or any other value other than 0%)
4) Heater Range -> 5
At step 4 it just immediately shows 'Heat 0% of OFF' rather than what I would expect as 'Heat 10% of 100W' or something along those lines.
One thing I don't quite understand is that when I set the Manual Output to, say, 10% the 10% value shows up over to the right of the PID settings as MOut + 10% (as if it's being added to the PID values in manual PID mode even though I selected Open Loop mode?).
Another possible issue I should mention is that I don't actually have any heaters or sensors connected to any of my lakeshore units yet. In other words, all of my feedback sensors are reading 'T. Over' and there is no resistor connected to the heater loop. Would that stop the LS340 from being able to change the heater range and correctly read it back as 5 rather than 0?
Any advice is welcome and thank you in advance!
~Clinton Davis
