Thermotron 8800

[plasmaphase]

So this sort of works in that the chamber now turns on and the setpoint moves to the correct temperature, however, the air temperature never changes.  I'm not sure if that's because I'm missing a throttle setting or setting the wrong channel (channel 1 is air temp for our thermotron).  I can see the Air Temp SetPoint (pink line) move to temperature according to the VI setting, but the Air Temp never changes.

Just to double check, I ran a manual (from our touch screen panel) setpoint and the chamber heated up quite nicely.

[montevan]

Change the Active Channel Code in the Set Initial Interval Values vi to a 1 instead of a 5 and try it again.  I am trying to simplify and just use one channel instead of both channels 1 and 3.

Also, when you run the vi, watch the throttle in the 7800 Status screen to make sure it is going positive.

[plasmaphase]

Yeah, removing all other channel values was the first thing I did, so I set the channel code to 1 (enabling only channel 1), and then whenever I set final values or deviation values, I only set channel 1.  This had the same result.  The Thermotron has the correct SetPoint, but no throttle and no temperature change.  It's almost like I'm missing a setting the Thermotron needs, but I didn't find a throttle setting anywhere, and I figured that was calculated through the time I provide (initial value to final value over time gives throttle).

If it's any consolation, I'd be willing to use the 7800 drivers if this is to difficult to get working.  The only reason I chose 8800 is because my thermotron states that it accepts 8800 messages and it seemed like it supported a more recent LabView version.

I really appreciate your assistance through this.

[plasmaphase]

I ran another couple tests with various configuration changes with no luck.  I also had several instances where, after changing a parameter such as channels enabled, the MFC application on the thermotron computer crashed and I had to unplug the computer.  Attached is the current vi.  I've also posted a screenshot of what the Thermotron is doing (ignore previous testing prior to reboot).  You'll see the setpoint at 61 but the temperature not changing at all.

Any suggestions?

[montevan]

Hmmm.

The last time we talked, you were using 8800 drivers for a 7800 but you included a screenshot from an 8800 so I am not sure what kind of chamber controller you are currently talking to...

In any case, if it is indeed an 8800, 

to go to Setup >> Backup/Restore >> Backup Wizard. Follow the wizard prompts, select ALL checkboxes when prompted, save one week’s worth of data when prompted. Create a backup file and attach it to a post. Get the backup to me and I will restore it on my 8800. I can learn a lot from it.

[montevan]

I tried your attached vi on my 7800 and it did not work until I changed the id query to false on the th8800-8200 Initialize.vi

Then it worked fine.

[plasmaphase]

Here's a 7 day backup.

[montevan · Accepted solution]

We have reviewed the backup data and have the following recommendations:

Please see attached vi that has been slightly modified.  A parameter group of 1 has been added to both Set Interval Programming vi.  The 8800 does not like a value of zero.

Also, the options code has been changed to 32 (cascade cooling).

[plasmaphase]

Fantastic, I see a change in temperature.  Thanks for all your help!

[plasmaphase]

As an aside (maybe I start a new topic?), is there a reasonably simple way to setup an interval such that it doesn't continue on until its temperature stabilizes?  In most of my intervals I have a specific time (10 min, 30 min, etc...) to run at a given temperature, but occassionally we need to basically set a temperature and then wait as long as it takes for that temperature to be reached before moving on (like monitoring our channel 3 which is the load temperature).