How do I monitor 17 thermocouples, 4 pressure transducers which have a 0-5 VDC output, and 2 current sources using the agilent 34970a with two 20 ch multiplexer cards and labview
I am using an rs-232 serial connection. I am also trying to contrl a watlow f4 with labview at the same time through another rs-232 port. I want to be able to log this information as well straight to my computer.
You start with downloading the driver for it here. I think the most appropriate example in the driver is the one called HP34970A Scanner Demo. I haven't used that specific one very much but you should be able to easily modify it to save measurement results to a file.
I think using a current shunt to measure your currents is necessary and will help here. I know the cards you are using have current channels but they are limited and can be a bit of a pain sometimes. If you use the shunts, all you have to do is hook up all the voltage channels sequentially and then the thermocouple channels. You can use a series of serial writes to set up the channels and then a simple serial write to trigger the unit to read them. Follow that with a read to get the data back off it in a long ASCII string. You could then use the String to Array function to separate your data as necessary and do what you like with it. I would recommend choosing the ranges for the voltage channels instead of using the AUTO setting. It will greatly speed up the read time. Thermocouples are the slowest type of channel to read using the 34970A so putting them all in line speeds the read up also and will tend to give you more accurate results. I use these things (Agilent 34970A) quite a bit and can give you more specific help if you need it.
