DAQCard 1200 / SC-2043-SG - Other Analogue Sensor Inputs?

[Bife]

Hello!

I am relatively new to these things, so sorry for any ignorance

I have a self designed servo-hydraulic structural test rig with a load cell and displacement sensor on the hydraulic cylinder.

Signals from both these sensors are inputted via a CB 50LP connector board and then a DAQCard 1200 to a PC using a Labview 6i program, through pins 1 and 2.

I also have an in-house made strain gauge signal box that inputs to pins 3, 4, 5 & 6.

The DAQ card is using NRSE.

Now, this all worked fine for years, but now the in-house strain gauge board is kaput, so I am trying to connect up a SC-2043-SG that we have instead of the kaput inhouse board and the CB 50LP.

I have read the DAQ Card and SC-2043-SG manuals, and pretty much understand what I have to do, but....

 Page 3.6 in the manual says, "Pins 1-8: Analog Input Channels 0 through 7—These pins carry the conditioned strain gauge bridge signals (referenced to AISENSE) to the DAQ board. They are not routed to screw terminals."

So my problem is, how can I connect the first two analogue channels (pins 1 & 2) to my load cell and displacement transducer, whilst using pins 3 to 8 for the strain gauges, with the SC-2043-SG?

I though I could just cut the 1 & 2 wires of the ribbon connector from the DAQ card to the SC-2043-SG and connect them directly to the sensors (and then not use strain gauge channels 1 & 2 on the SC-2043-SG), but am not sure if this would work / have any unwanted implications.

Would this be OK, or is there an easier, neater way?

Thanks

Bife

[thomas.baudouin · Accepted solution]

Hi Bife,

The SC-2043 is designed for strain gauge only, so you can't connect basic voltage signals.
It is true that you can cut the cable in order to provide your own signals to the DAQ card.
(not recommended, but it should work)
You can also contact us so that we can suggest a better hardware (maybe the SC-2345 that can do multiple types of signal conditionning in a single enclosure).

Best regards,

[Bife]

Thanks Thomas,

I found two extra PR50-50F cables and cut the pin 1 & 2 wires and linked them directly to the +-5V load cell and displacement transducers and all works fine.

The only problem is that I am stuck with the 10x amplification of the SC-2043-SG for the strain gauges (100x would be better), and I cannot increase the software gain of the DAQCard without going out of range for the loadcell and displacement transducer channels.

Bife

[Bife]

Couldn't find a way of editting my previous post, I guess I have a limited time to edit?

I meant to say,

I found two spare PR50-50F cables and so I cut the pin 1 & 2 wires on one of these and linked the DAQCard ends of them directly to the +-5V load cell and displacement transducers and all works fine.

The only problem is that I am stuck with the 10x amplification of the SC-2043-SG for the strain gauges (100x would be better), and I cannot increase the software gain of the DAQCard without going out of range for the loadcell and displacement transducer channels.

Bife

[Bife]

In case anyone has a similar problem...

I soldered a jumper between pins 1 and 8 of the little AD621 amplifiers.

Now, for each channel, with the jumper connecting pins 1 & 8 I get an amp of x100, instead of the x10 without these pins connected

Actually, since it was really small, fiddly work I got someone who does this sort of thing all day to solder for me!