Mantaining Temperature with Lakeshore Temperature Controller 331

[Dennis_Knutson]

The invalid reference is of concern. You need to select the correct resource from the drop down menu.  The connected property is used only for NI serial devices so ignore that.

You say you sent a command but do not exactly say what the command was.

[Sufun]

I forgot to select the reference today. When I switched to COM1, I got timeout errors again.

I'm sending commands through VISa test panel using strings provided in the LakeShore value. Some examples:

*IDN? - identification query

SETP 1,200 - change setpoint to 200

[Sufun]

I am now using a Serial Write and Read VI to try sending command strings to the temperature controller but still can't get a response. There does seem to be a problem in the Initiliaze sub-VI of the driver VI. It returns the error message in the picture but only for the ID query option.

[Dennis_Knutson]

You do not show any termination character(s) with the write string. If you do not terminate the command correctly, you will not get the read to work. The initialize fails with the ID Query option since that is the only option that the instrument is read. See the manual to determine what the correct termination character(s) should be. The VI I looked at appends a CR/LF. In the VISA interactive control, you would use a \r\n.

You need to double check the com settings match at both ends and you need to verify you are using the correct type of serial cable. There are two types.

[Lakeshore3]

Dear all

I want to interface LakeShore 331 Temperature Controller using Labview 8.6.

I am connecting it using RS232

I am not able to identify the temperature controller. It is give unusual output

for example *IDN?\r\n

I should get: LSCI,MODEL331S,123456,020300

but I am getting 

LÓCI,ÍOÄEL³³1E,³³¶°27,12°4°7
Š

I have checked the loop back test with the cable and it is working well.

I did not understand where is the problem.

Kindly suggest me the possible solution.

I am attaching the pdf file of front panel and block diagram.

Thanks in advance

[Lakeshore3]

I have solved this issue.