LOVE Series 16C Temperature Controller

[rv_labView]

I am trying to get and set temperature using this device using LabVIEW. I am able to communicate with the controller and it is responding to my write message. But when I try to say set a temperature of 28C, it sets it as 2.8C instead. Write command used is ":02064701001C94" to set 28C. Can anyone please tell me what am doing wrong? (code & manual (pg 17 attached)

http://www.dwyer-inst.com/PDF_files/E_90_CPC_rev4.pdf

[aeastet]

Try to send the command:

02064701011894

If this works then it would be because the controller is set to use one decimal. You need to send it a value that you can add a decimal to. It should be that easy. If you change the decimal setting in the controller it would change what you need to send the controller. This is what I have seen in the past.

I don't have that controller to prove what I believe is going on. To make your program flexible you will need to read out the decimal position and send the commands using that info.

Tim

[rv_labView]

Hello Tim,

Thanks a lot! It saved my day.

Since you are familiar with this controller, could you also see if am doing anything wrong in the get vi? I am always getting a value of 51.2C when it is reading a temperature around 24C. Read string: "02032F020001C9", where "0200" is the value in hexadecimal which when converted to decimal and divided by 10 gives me 51.2C. Any ideas?

[aeastet]

OK first I think you are reading the wrong part of the response.

"02032F020001C9"

If I am reading the info you attached correctly you should be looking at "0001" section of the response:

"02032F020001C9"

Now the problem here is that I see the value of 1 when I do that. I am not sure what you are doing here. I have not used this exact controller before. I have used a controller from a different company that seems to act a lot like this one.

[rv_labView]

In the get vi, am writing a command to the controller ":020347000002B2" to read the temperature displayed on the temperature controller. Then am reading back from the temperature controller which gives back a command string "02032F0020001C9". If you refer pg 16 of the instruction manual attached, you will see "0200" is the "Content of start address 4700H". This is why I came to the conclusion that this is the part which contains the data. Let me know if you have any more ideas. (see you tomorrow)

[aeastet]

It looks like to me that you need to send this value:

020347000002B3

If you send this what do you see as a response? Also what is the temp when you ask for this?

[aeastet]

Also try to send this and give me the values you are seeing and the temp:

020347000003B3

[EamonnFPMcKernan · Accepted solution]

You commanded 2.8 C and got 2.8 C. The units (p.16) say .1C Multiply your hex number by 10. . . .

[aeastet]

OK here is a vi that will calculate the command to the device. I would try to read 2 words and three words. This might be what the problem is. You are only reading two words at the moment. I would try to read three and see what we see.

I realize there is an easier way to do this I just wanted you to see what I did to get to this value. It matches the document that you attached as reference.

[aeastet]

OK I made a command generator using a ring. You can set the values and it will generate a command for each parameter. I also added an interpret vi. I don't have enough data to know if what I am doing is correct.

I would try to read the PV with one word.then 2 then three. This way we can try to see what the system is really sending since what you set me does not match to what they tell us to expect.