03-29-2018 02:23 PM
I'm communicating with an Espec P-300 controller, using Labview to start profiles, create profiles, etc. remotely. One issue though, when in "constant" mode you can live-update the temp and humidity to create unusual profiles and such, but I can't figure out to turn off humidity control once it's on. If I want to control the humidity in one step and then turn off the control in the next step, I can't find a way to do it. It just maintains its last value. Anybody who has worked with an Espec controller (Labview driver works with several models) know how to do this?
Thanks,
MattManML
Solved! Go to Solution.
03-30-2018 01:51 PM
Is there a manual you have for the controller? Looking at the driver for LabVIEW, it looks like it just sends a state command via VISA to the instrument to update the control mode. It'd be good to make sure that the instrument can operate with just temperature or humidity control, instead of both or neither.
03-31-2018 06:49 AM
Thanks for the reply Claire. The temperature must always be specified but you can turn off humidity control from one step to the next. I've manually input profiles that do it so I know it's capable. I just can't find the option in the VI's.
03-31-2018 10:16 AM
They make a big secret of their programmers manual by only letting you download one if you have a serial number of a recent device. So hard to help more beyond general recommendations.
04-02-2018 03:18 PM
Ah, gotcha! Yeah, as rolfk said, my recommendations are going to be pretty general. I might suggest digging into the driver VIs to see how profiles are input there and compare them to how you were inputting profiles manually. This eventually might entail creating another VI (probably based on one of the currently existing ones) whose purpose is to turn off and on humidity control, or it could just mean adding onto the current humidity control VI.
04-02-2018 03:29 PM
@MattManML wrote:
Thanks for the reply Claire. The temperature must always be specified but you can turn off humidity control from one step to the next. I've manually input profiles that do it so I know it's capable. I just can't find the option in the VI's.
Again, I can't see the driver or the documentation but, I would seriously reconsider how you are using that radio button. When you need a boolean use a boolean.
04-02-2018 04:46 PM
Thanks. I started going through the input vi's but the real low-level code goes a little over my head. From the code in the vi you can see there's a code to identify the input: S for set point, H for upper limit, L for lower limit. But whether this is some kind of common code or is this a key unique to espec machines I have no idea; or where I could find a list or something of possible inputs.
In the "output" image you can see it specifies "HUMI" and then the variables but I don't know what kind of input the controller would understand. If anyone has any idea how I could proceed I would be extremely grateful.
Thanks again,
MattManML
04-02-2018 04:56 PM
Lets see a snip showing the other case in background. It appears that entering a NaN value does interersting things
04-02-2018 05:02 PM
Here is the other case. It looks like it defaults to no input. I've tried entering NaN as the set point before but it ignores it.
04-03-2018 12:44 PM
Hey everyone. I figured it out. The vi converts the humidity set point to a string and puts S it front of it as an identifier (e.g. S65.0). By sending the string (SOFF) it shuts off the humidity control.
Thanks again for everyone's help and suggestions.