Xantrex XKW driver... does it work?

[MrStu]

Hello,

I'm new to LabView, GPIB etc. I'm struggling to control the above power supply using the drivers available. I've wired it up for the 'getting started' VI and this now runs without any errors. However, it doesn't really work in that it doesn't seem to attempt to reach the voltage / current I ask it to. If I enter 150 V it shows that the actual output is about 0.3 V! Has anyone else used these drivers successfully? Does anyone have an idea where I've gone wrong? Any help would be very much appreciated.

Thank you.

Stu.

[_xs_]

Hi Stu:

I work for Xantrex and noticed your message.  Could you supply a little more information?  What version of LabVIEW are you using?  What version of the instrument drivers are you using?  What model XKW are you using?  What are all the settings that you are sending to the power supply?  To set a voltage, you need to supply a current greater than 0 and an OVP (over-voltage protection) setting greater than the voltage setting.  Can you tell me what lights are on on the front panel after running the getting started vi?

I have forwarded this message to the engineers responsible for maintaining the instrument drivers.  If you provide answers to these questions, I'm sure we can help you.

Rob

[MrStu]

Hi Rob,

Thank you very much for the offer of help. To answer your questions, I'm running LabView 7.1 and the Xantrex XKW driver version 2.0 (downloaded from http://sine.ni.com/apps/we/niid_web_display.drv_results?p_app_area=&p_man=xantrex&p_keywords=&p_inst...=).

The power supply is an XKW 300-10.

The settings I've put into the getting started vi are: OVP 250 V, Voltage setpoint 150 V, Current setpoint 5 A. (This gives an output voltage and current in the vi of about 0.2 V and 0.003 A respectively.)

After running the vi the REM and ADR lights on the front panel are lit. (Though pressing the REM/LOC switch seems to have absolutely no effect on the running of the vi - I don't know if this shows I've done something very stupid!) The light above the voltage knob is also on. The voltage and current readouts on the front panel both read zero.

I hope that this will make it possible for you to see what I'm doing wrong. Any suggestions you may have would be gratefully received.

Thank you again for taking the time to reply to my message.

Stu.

[XtxFirmEng]

Hi Stu:

I'm one of the Xantrex Engineers responsible for programmable power supplies group.  I have read you description of the problem and I have a few more questions for you.  Can you look at the jumper settings for the switch SW1 on the back of the power supply and tell me what the value is, where the switching being down is 0 and the switch being up is 1? 

Could you send to the power supply the following query "OUT?" and tell me what response you get.  You can send the  command using the method of your choosing but I would recommend using the NI GPIB Explorer program that comes with NI cards.  If you start the GPIB Explorer program select the Devices and Interface -> GPIB0 -> Instrument0  (assuming that the XKW is instrument 0). If no instrument show up under the GPIB0 interface select the GPIB0 interface and click the Scan for Instruments button with the XKW attached and powered up.   Clicking the Communicate with Instrument button.  Once you have done this an interface window will appear.  In the Send String box type the OUT? command and click the Query button.  The response will appear in the window below.  Note that if you hit enter after typing the command string this causes the program to exit without warning (window just disappears, its a little annoying at first).

Please post back your results and we can go from there.     

Chris

[MrStu]

Hi Chris,

Thank you for your help, it really is extremely good of you. To answer your questions:

I understand the value of switch SW1 to be 01110111. (Just in case I've misunderstood / read it incorrectly: The jumpers are numbered 1 to 8 from left to right and this is how I have written them down. So, jumpers 1 and 5 are down and the rest are up.)

Thank you for your clear instructions for sending the OUT? query to the power supply. They made it very easy, even for me! The response that appeared in the 'string received' window was: OUT 1

I hope this means more to you than me and I look forward to hearing back from you.

Thanks again,

Stu.

[XtxFirmEng]

Hi MrStu,

Great, we have established that communication to the unit is not the problem and the output is enabled.  Can I get you to send the following queries and post the responses for each: STS?, ASTS? and FOLD?.  This should tell me how the unit is configured and hopefully why you aren't seeing the output change will jump out. 

Regards,

Chris

[MrStu]

Hi Chris,

Sounds like good news. Here's the information you asked for:

STS? response was STS 1

ASTS? response was ASTS 3

FOLD? response was FOLD 0

Thank you for your continued help.

Stu.

[XtxFirmEng]

Hi Stu,

So far so good, there is no foldback or external shutdown pins causing problems. 

Now we will want to get a little more involved.  We need to know if you can set the supplies output using the command interface.  Can you send the following series of commands and watch the output of the power supply and report back the response you get? You should send the commands with no load on the output of the power supply.  The commands are:

ISET 1

VSET 150

VSET?  (send as query and verify the response if 150)

Now check to see if the display on the XKW shows the output of 150. 

Chris

[MrStu]

Hi Chris,

I've sent the commands you listed above. I guess that ISET 1 and VSET 150 are sent by clicking on the 'write' button so that's what I did. I hope this is ok and that I shouldn't have done it by some other method.

On sending ISET 1 and VSET 150 nothing appeared in the response window and there were no changes on the front panel display of the power supply.

When the query VSET? was sent the response was VSET 150.000. At no point did the display on the XKW show anything other than zeros.

I hope this provides you with some clue as to what is going wrong.

Many thanks for your expert help.

Stu.

[XtxFirmEng]

Hi Stu,

Yes, your response were correct, you should not have gotten any response from the ISET and VSET commands and were in fact supposed to use the Write button. 

Okay, so we can eliminate the problem from being in your driver.  It looks like there is a configuration problem with how the unit is setup. Again, I have more commands for you to send and a few questions.  We'll start with the questions, is there any other LEDs or lights illuminated on the front panel aside from the REM and ADR?   Can you send the following queries and tell me the response you get: IMAX? and HOLD? The last question is can you also post the serial number of your unit, this will allow me to find the actual hardware in the unit. 

Speak to you soon. 

Chris