How to control instrument switch through PCI-6503 & 50-pin I/O connector

[labviewer]

Hi, everyone:

I have a problem in controlling an instrument switch which switch position between zero point and measuring point every five minutes during experiment. The hardware used is PCI-6503 card & corresponding 50-pin I/O connector, cable and the software is labview.

The instrument manufacturer provide a cable(25-pol.SubD-plug male)for connection to computer(or DAQ board).The instrument manual showed the following pin assignment for this cable:

25-pol subD-male pin assignment(TTL-level):

meaning zero point measuring point
Pin 9 MP L H
Pin 7 ZP H L
Pin 23 Gnd
Pin 18 Gnd
Pin 4
Remote H H
Pin 3 Weight1 H L
Pin 2 Weight2 L H
Pin 5 Gnd

(weight1&weight2 is for calibration purpose)
I want to connect these cable pins to Port A(pin 33-47) of I/O connector and then using labview easy digital I/O "write to a single port.vi" to programming it. But I don't know how to connect these pins. For example, pin-5,pin-23,pin-18 is Ground, how can I realize it ? Do I need to connect other pins in 25-pol sub-D plug(besides above 8-pins) male to 50-pinvI/O connector or just leave it alone? Hope everyone give me idea. Of course, the detail is preferred since I have a good background in electronic.

Also I will be very happy if everyone have a labview programming sample in similiar application.

Thank you very much for help!

Sincerely
Jingjun

[Filipe A.]

Hello;

My understanding is that you need to connect each one of the GND pins to each one of the GND pins of the DAQ board. By doing that you will be creating the reference to the TTL signals being read on the DAQ board. The MP and ZP would go to any digital line of the preferrable Port and you should be good to go. As far as I'm concerned, you don't need to make any extra connection.
I don't know exactly what you are willing to do with the data but, once the data changes each five minutes, you don't need any speed digital application. If you take a look at the Labview shipping examples for 6503 doing read from 1 Digital Port.vi, you should be ok.
Hope this helps.
Filipe