How to read drive fault in Labview

[RobDekker]

I have a 4 axis machine and I am controlling it using 4 servo drives and a NI 7350 motion control card with the UMI-7774 on Labview RT target.

Does anyone know how to read in the "drive fault" input or "drive enable" output status in Labview?  The fault signal is working (drive is disabled when it there is a fault and the LED on the UMI turns) but I can't figure out how the check the status.  I want to stop the other axes if a fault occurs, and right now they keep on going if one axis is disabled.

Any suggestions would be appreciated.

[GiGe]

Hi Rob,

One thing that you can do is take what you have wired to the fault line and wire it to one of the digital lines on the 7350 card.  You can read the digital line in labview using the Read I/O Port vi.  I hope this helps. 

Regards,

gg

[RobDekker]

I was hoping that was not the only way to do it.  Why does everything in Labview have to be so hard???  I have already used up the 8 inputs and 4 triggers on the 7774 board so I can't use that option.  I may have to hook them up to the analog inputs or something.  This leads me to another question:

I have the NI7354 4-axis motion controller.  It is supposed to have 64 digital I/O (32 associated with axis 1-4).  When I hook it up to the NI7774 board, only 16 of the I/O seems to be available.  Is there any way to use the remaining 16 I/O or does the board waste them?

thanks,

rob

[GiGe]

Hi Rob,
Sorry that there isn't a easier way to do that.  But if you would like to use all 32 digital lines on the 7354 then you can use a SSR cable adaptor and then connect that cable adaptor to an SSR Series backplane.  This is discribed better on page 3-3 of user manual for the UMI 7774.


Regards,
GG

[Jochen]

Rob,

in addition to the digital lines there are eight analog inputs on the 7354. Four of them are accessible through tha Analog Input Connector on the UMI-7774. I know that using an analog input for reading a digital signal is kind of a makeshift solution, but on the other hand it's better than adding more connector boxes to your setup.

Best regards,

Jochen Klier
National Instruments