GPIB changed all default

[009242]

Our gpib when we insert some number for velocity or moving it does  twice of numbers!!!in other word when I commanded MRCn=10mm it moves 20mm,when I commanded Un=2mm/s ,initial of velocity that it moves ,is 4mm/s!!how can I changeit that when I will command it dosent twice of numbers!!!

[NathanT]

Hello Najima,
       Please elaborate on what hardware and software you are using.  You can also use NI-Spy to see what is actually being passed over the GPIB Bus.  If the correct values are being passed, then the issue is most likely in your hardware configuration, which might be changed by a firmware upgrade or just sending different configuration commands.

       Don't forget that you can always have a software workaround in which your application just divides all values by two before sending them to the instrument.

Cheers,

NathanT

[009242]

hi,
when I communicated manually,or I inter numbers from every programs like (visual basic,lab view) nanostepper that connect to GPIB moves twice of the numbers that I inter,and when I command MCAL it  doesnt go at 0 default

[Can_W]

Hey Najima,
Looking at the situation, it seems that either your program is sending the commands twice, which is why you see the double movement, or your device is doubling the input. One way to verify which one is the case is to use NI-SPY as Nathan had stated. This program, found under Start->Programs->National Instrument, will display everything that is being sent on the GPIB line. If you see that there are two of every move command, something in your code is causing it to be sent out twice. If it looks like the correct manner that you expect it to, then your device may be doubling the input, something you may have to discuss with the manufacturer of the device. You still have options if the device is the cause, just divide your target distance and send that through your code.

Hope this helps.

[009242]

  Hi,
2 month ago when my friend tried it ,it didnt work lik now,but now it changed(I dont know why!!) ,can I reset it?and when I command MCAL it goes to around the right place!in other word  when I command MCAL it should go to point 0 as adefault but it goes to 2mm front of 0!!and I wantcorrect this one,another problems : when I command manually ,or I command with labview or visual it works like that, I dont know whats wrong in my cods,could you explain more about"your code is causing it"?and how can currect codes?
and it is not just about distance when I inter 3mm/s for velcity it goes by 6mm/s!!
thanks for helping

[Dennis_Knutson]

You HAVE to run NI-Spy. Can and Nathan have both told you that. That is the only way to tell if you are sending the incorrect command or if the instrument is not working the way you think it is supposed to. Ni-spy will tell you exactly what is being sent. If the commands are correct, then you should contact the vendor.

Ni-Spy can be started from MAX (Measurement & Automation Explorer). It's on the Tools menu under NI-488.2.