What are the most common causes of Modal Error with the PCI-7344 board?

[kl773]

I continue to get more and more modal errors from the board. The VIs send motion commands to the board and also monitor the position of the axis. The strangest part of all this is that I rarely saw modal errors and now they are becomming common and the VIs have not changed...actually the program has been compiled to an *.exe. The PC I am using is a DELL w/ a 2GHz processor and 512M RAM.

[Kyle_V]

Hello.

Modal errors occur inside the motion control hardware and can sometimes be hard to pinpoint since they only show themselves after a program is finished running. The exact nature of a modal error can be diagnosed under the 1D Interactive window in the Measurement & Automation Explorer (MAX).

Often times, modal errors result from programs that frequently update their target positions or velocities. With increasingly faster computers, it is possible for a PC to overflow the motion control card's input buffer with new positions and velocities. This will result in a modal error. The way to work around this is to make sure your loop times aren't faster the 10ms. This will guarantee that the motion controller will be able to keep up with your fast computer
.

However, if your motion control board returns "a modal error 0 occured at < >", then you may have a hardware watchdog error and will need to call NI tech support to clear it up.

Please keep us updated on the status.

Kyle V