Sys Info: Windows98\Labview6.1\PCI-6025E connected thru SCB-100.
Problem: Trying to control a hydraulic press using Labview. Tested the card connections using MAX & everything appears to work as it should except for the fact that when the signal to close the press is turned off, the press continues to close. The same thing happens with signal to open the press. The close press signal is wired through DGND & DIO4 of the card connected to a solid state relay (SSR). I have bypassed the card completely by connecting a stand alone power supply giving out a 5V signal to the SSR and the system functions as it should,i.e. closes with the power on & stops with the power off, so I know that the press itself is wired correctly. The potential acr
oss the output side of the relay is 0V when the press is closing & 24V when the press is stopped. I then checked the card with a voltmeter and it too gives a clean 0-5V signal through the PC, but when I connect it to the SSR in the press it will work once or twice, i.e. start & stop as the signal is turned on & off but then instead of the potential on the output side of the relay returning to 24V to stop the press, it only goes to 9V and the press continues to close. I have grounded the card to the press system because I thought it might be a ground reference problem, but that didn't fix the problem. I have also connected the card as both sinking & sourcing digital I/O, and the sinking configuration works the best, but still not all of the time. I don't know what else to try, hence the posting. Is there something about using digital I/O I'm missing? I don't understand why the PC generated 0-5V signal should be any different from the power supply generated one, but one works & the other
doesn't. Any suggestions? Thanks.
