AMUX-64T and SC-2042-RTD connections

[rkikdnec]

I am looking into purchasing an AMUX-64T board for use with thermocouples and a 6033E-Series DAQ board, which I already have.  It seems that the recommended way to connect this board to my DAQ board is with a R1005050 cable, which I own.  I can't seem to find, however, if it matters which 50 pin connector (pins 1-50 or 51-100) must be connected to the AMUX-64T.  Currently, I have the pin 1-50 connector going from my 6033E to a SC-2042-RTD board.  (This RTD board must use the pin 1-50 connector, according to its manual.)  Can I simply attach the AMUX-64T board to the pin 51-100 connector and use both the AMUX-64T and the SC-2042-RTD simultaneously?  If not, what additional cables or hardware will I need in order to connect and use both the AMUX-64T and the SC-2042-RTD to my 6033E at the same time?

[S_Kanchap]

Amux-64 is a multiplexer card as you know and it is used for analog inputs so if you are using 100 pin cable with 2 connector e.g. 1-50, 51-100 then you must connect that connector that has analog inputs not dio etc. ckeck the manual of daq card and amux again!

[rkikdnec]

Thanks for the response.  It seems that the AMUX-64T requires 16 analog input channels as well as the AISense and AIGND connections.  However, there is no mention in its manual of a pin-out configuration.  It only references a "50-pin MIO cable".  With my 6033E Daq board, pins 1-50 include the first 16 analog input channels, 0-15, as well as AIGND, AISense, and the digital I/O channels.  Pins 51-100 are the remaining analog input channels (>16), along with AIGND and AISense2.  Does this mean that either connector (1-50 or 51-100) would work with the AMUX-64T?  They both seem to have the necessary channels, though the AISense and AIGND correspond to different pins on each 50-pin connector.  I guess what I'm really asking for is a pin-out map for the AMUX-64T.  Thanks again.

[Hal_L]

Hi,

You will be able to use the R1005050 with the PCI-6033E and the AMUX 64T. I think that the pinout you are looking for is located in the E Series Help Manual. Open it and go to I/O Connector >> I/O Connector Pinouts >> 100-50-50 Extended AI/AO.  I want to point out that since J1 and J2 are tied together on the AMUX 64T, you will only be able to use one of the 50 pin slots with your board.

Regards,
Hal L.

[rkikdnec]

After looking at the document Hal suggested, I'm still left with a few questions.  For the 6033E Daq board, when split into two 50-pin connectors, on the pin 1-50 cable, AIGND is on pins 1 and 2.  Pins 3-18 are the 16 analog input channels, and pin 19 is the AISense channel.  These are all the channels that are required by the AMUX-64T.  On the pin 51-100 cable, pins 1 and 2 would not be AIGND pins, but rather two analog input channels.  Pins 3-18 would be analog input channels, the same as the pin 1-50 connector.  However, pin 19 is another analog input channel instead of an AISense channel.  The AISense2 and AIGND channels are located on pins 25 and 26 of the pin 51-100 connector, respectively.  On the pin 1-50 connector, pins 25 and 26 are P0.0 and P0.4, respectively.  I suppose it's possible that the AMUX-64T has pins 1,2, and 26 wired as AIGND and pins 19 and 25 wired as AISense, but I just don't know.

That's why I need the pin assignments for the AMUX-64T side of the connection.  What are the pins 1-50 (on both jumpers J1 and J2... which are the same) connected to on the AMUX-64T board?

[Logan_K]

Basically, you cannot use the AMUX 64T with the second 50-pin connector. The in addition to the 16 AI channels and the AISENSE and AIGND, the AMUX 64T also requires the digital I/O lines from port 0 of the DAQ board to switch the multiplexers, and the second connector does not provide access to any of the DIO lines.

Regards,
Logan K
National Instruments R&D

[rkikdnec]

Thank you very much.  That's what I needed to know.  So my next question would be, is it possible to hook up both the AMUX-64T and the SC-2042-RTD to my single 6033E DAQ board at the same time by some other method of cables or switching hardware?  Or, if there is a better solution than the AMUX-64T, I'd like to hear about it.  Basically I already have the RTD board and the DAQ card, and I just want to add thermocouple functionality at the same time.  I don't really need the multiplexing, as I only need to use up to 10 thermocouples at a time.  (Even 8 would probably work for me.)  Thanks again!

[Logan_K]

If you are looking at the AMUX-64T for thermocouple measurements, then I am assuming you don't care very much about the overall accuracy of your readings. A comparable solution would be to use the SCB-68 because it has a CJC temperature sensor that you can route to channel 0 (which maps to AI 17 on the second connector of the 6033E). Then you can use the rest of the channels to connect thermocouples to. The CJC temperature readings will not be very accurate because the SCB-68 is not isothermoal (neither was the AMUX-64T) - but at least the accuracy of the thermocouple readings will be slightly better than with the AMUX-64T because you won't have additional noise injected from the multiplexer. But, since you are only using a 16 bit DAQ board, your overall accuracy is going to be severely limited (>5 degC accuracy at least). If this sort of accuracy is acceptable to you, then this will be the cheapest and easiest way to leverage your existing DAQ board.

-Logan K