LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Serial communication with Instek PSP-603 power supply?

Solved!
Go to solution

Hi,

 

I am trying to control an Instek PSP-603 programmable power supply via the built in RS-232 communication. I found a thread in the forum covering this:

 

http://forums.ni.com/ni/board/message?board.id=170&message.id=384686&query.id=49195#M384686

 

However, my problem is not solved by the solution there. I have tried all the things suggested there, but I am still not able to read from the PSP. After adjusting the settings for the termination characters I was able to write to the instrument (I was able to adjust the settings from the computer). I think it is very strange that the read still does not work.

 

Does anyone have any suggestions as to what might be the problem?

 

Thanks for any help!

 

Clara

0 Kudos
Message 1 of 16
(7,180 Views)

I looked this thread and it seems that they never mentionned that you have to connect the pin #4 with a 12 VDC.  I have a PSP-2010 and the only way to read from this instrument is to connect the pin #4 with an external 12 VDC power supply.  Maybe the PSP-603 is different but at the page 14 of the "PSP-OM programming manual" you have this:

 

Drawing1.jpg

 

Jean-Marc

Jean-Marc
LV2009 and LV2013
Free PDF Report with iTextSharp
0 Kudos
Message 2 of 16
(7,170 Views)

Thanks J-M, this could very well be the problem. I saw this in the manual too, but isn't serial communiction by 12 V signals? But then again, I don't know how to achieve this "constant high signal" on a specific pin.

 

Is this a common system to connect an external power supply? How did you do it physically? Did you cut off the cable to solder on an additional power supply? I am not very familiar with this. There must be some kind of special cable for this?

 

 

I was also told that I should use an I/O card to read from the instrument. However, the manual does not mention anything about this?

 

 

Thanks again!

  

0 Kudos
Message 3 of 16
(7,142 Views)
Solution
Accepted by topic author Clara G

I am not a specialist in serial communication but in the Serial Quick Reference Guide (http://www.ni.com/pdf/manuals/371253a.pdf)you could see that the rs232 is not a constant 12VDC.

 

RS232 final.jpg

 

You have to build your own null modem cable.  The pin #4 is connected to the +12VDC of a power supply.  The power supply I used is the cheapest available at the electronic store (20$ - 12 VDC and 40 watts). I am ashamed to show you my own cable, but this should give you an idea.

 

Photo.jpg

 

 

Jean-Marc

 

 

 

 

Jean-Marc
LV2009 and LV2013
Free PDF Report with iTextSharp
0 Kudos
Message 4 of 16
(7,132 Views)

Thanks!

 

That was the way to do it. Not really a standard solution if you ask me...

 

I am too ashamed to show you my cable. 😉

 

Clara

0 Kudos
Message 5 of 16
(7,083 Views)

Hi again J-M,

 

I got the communication with my power supply to work with the solution you suggested, but with some limitations (see this thread). I was just wondering if I did some mistake in the cabling? To what did you connect the - side of your 12 VDC power supply?

 

Clara

0 Kudos
Message 6 of 16
(6,978 Views)

@Clara G wrote:

Thanks J-M, this could very well be the problem. I saw this in the manual too, but isn't serial communiction by 12 V signals? But then again, I don't know how to achieve this "constant high signal" on a specific pin.

 

Hi Clara

 

You can use "Property nod" for activate DTR Line and ather liles of RS-232 port and also for state control all lines. see attachment.

0 Kudos
Message 7 of 16
(6,415 Views)

Dear All

 

looking for Help

 

I have programmable power supply Chroma Model 62012P-40-120. I write RS232 communication based on the protocol from the manufacturer to set volatge ,current to the supply and measure the volatge and current output from the power supply. I have no problem with the communication . i can set the volatge and the current to the power supply and i can remotelly control (ON/OFF) the DC ouput of the supply. But when i try request volatge and current output of the power supply and connect them in series i can read the measure output either the volatge or the current but not both.

if the measure volatge request is 1st i can read it but no the current request and vise versa. But i can see the volatge and current ouput in the screen of the Power supply. Here i have attached the screent shoots of my labview programs. The status message is OK in both cases.

0 Kudos
Message 8 of 16
(6,371 Views)

 

bstar,

 

You have hijacked 3 threads with a similar question.  Please start your own thread by doing a search and if you do not find what you wish to accomplish (and there are thousands of posts on serial port), then you can post your own question.

 

The other threads are:

 

http://forums.ni.com/t5/LabVIEW/remote-controlling-a-DC-power-supply/m-p/1322753#M540603

http://forums.ni.com/t5/LabVIEW/How-to-make-program-for-RS-232/m-p/1322721#M540596

 

______________________________________________________________________
0 Kudos
Message 9 of 16
(6,363 Views)

Keep in mind that the PSP series does not use an UART (it seems) so you have to allow 150mS or so between msgs. I have also found sometimes you have to write twice to it to be more sure it "gets it". But the price and performance of this unit is a great deal.

barry


0 Kudos
Message 10 of 16
(6,321 Views)