DAQ Assistant Connection Diagram has different pinnouts than on the SCC-68

[NI_LV_82_User]

When looking at the Connection Diagram on LabVIEW 8.2.1 (from DAQ Assistant) The diagram shows pins 34, 66, 31, and 63 ABOVE pins 68, 33, 65 & 30.  However, when looking at the physical layout on the SCC-68, these pins are transposed.  That is to say that pins 68, 33, 65 & 30 are ABOVE 34, 66, 31, and 63 respectively.

Is this an error?  If not, what is the logic behind this?

[LabViewGuruWannabe]

I'll have to check my SCC-68 board when I get back to the shop, to see if its the same or different than the connection diagram. However, I wouldn't be concerned if the physical layout looks different. What would concern me is if the pin diagram says some data channel is on pin 48, when it is actually on pin 20. I know the terminal boards are designed for a variety of DAQ cards, and that there are several versions (and manufacturers for that matter) of the breakout boards.

B-)

[RVallieu]

I am noting this as well.

The connections diagram in MAX says that ai4 is mapped to pins 28 and 61 (64 being AI GND), whereas the connections on the SCC-68 reference label that ship with the SCC-68 say that ai4 is on pins 28 and 64 (64 being AI GND).

If I check for ai5 the reference label says pin 60 for ai+ and pin 59 is AI GND.  MAX connection diagram says pin 60 ai+ and 26 for AI GND.  I suspect the rest of the analog input channels will also have this discrepancy.

Which one is correct?!@ 

I can't get a good reading on ai4 using either of these connection pinouts.  I have a 5VDC source as my input to test my daq board and I am not seeing 5V.

This SCC-68 is connected to a PXI-6221 via cable SHC-68-68EPM.

This is with LV 8.5 and the latest DAQmx drivers installed.

Message Edited by RVallieu on 12-07-2007 04:25 PM

[Ben]

I Knee-dragger,

Quick Q

Are you sure MAX has the terminal block configured as a SCC-68 and not a SCB-68?

Ben

[Vanessa L]

Hi RVallieu,

I think the disprepancies in the connection diagram that you are seeing are related to the type of connection you want to do.  For instance, if you are doing differential measurements (good for rejecting Common Mode Noise Voltage), you would connect the positive lead to ai4 (pin 28) and the negative to ai12 (pin 61).  On the other hand, if you are doing Single-Ended Ground Referenced (RSE) using channel 4, you would connect the positive lead to ai4 (pin 28) and the negative to ai gnd (pin 64).  Whichever of these measurements that you choose, make sure that you configure the measurement type in MAX when you set up your task or in the VIs in LabVIEW under terminal configuration.  Here is a link to a document that describes the differences in these measurement types. Table 1 breaks the information down into Signal Type and Input Configuration.

I opened up both the Device Pinouts in MAX for the 6221 and the manual for the SCC-68 (page 39) and compared the pins and they seem to correlate.  Since the SCC-68 works with multiple M and E series DAQ devices, they should be the same. 

As far as your measurement value is concerned, Ben has a good point that you may not have configured the accessory correctly in MAX.  To do this, right click on your 6221 device and go to properties.  Then in the accessory tab, you can select the SCC-68.  This knowlegdebase describes the differences between SCB-68 and SCC-68 in case you were wondering. Hopefully this information will help!

[RVallieu]

Yes, configured correctly in MAX with SCC-68.

Everything is working, thanks for the help.

Message Edited by RVallieu on 01-04-2008 08:24 AM