Connection of NI PXI 4110 tO TBX-68T

[yongster]

Hi

how do i connect the power supply to TBX-68T

pictures will help a lot

i need more than 20 Volts...........

[Abhinav T]

Hi yongster,

The output of the 4110 can be used in various ways to achieve different voltages. There are a few things that need clarification:

- What voltage are you trying to output?
- What do you want to do with the power supply on the TBX-68T?
- Most DAQ card connected to the TBX-68T can only take a maximum of 10V - where are you routing the signals to?

Thanks,

Abhinav T.
Applications Engineer
National Instruments

[yongster]

Hi

great to hear from you

i have attached some slides to better explain the scenario, hope everything is clear if not let me know........

please give advice on connections

thks

[Abhinav T]

Yongster,

Your powerpoint presentation is not very clear. Here's what I think you're trying to do:

- there are 8 connections
- 4 go to RTDs to measure temperature
- 4 control heaters

The RTDs can be connected to the TBX-68T by connecting IEX+ and IEX- channels (pins 12 and 45) to the excitation inputs of the RTD. The output of the RTD should be connected to the input channels on the TBX-68T.

In order to control your heaters, you can connect the power output on the 4110 to your heaters. In order to get more than 20V on the 4110, you will need to cascade the outputs in series.

Can you confirm this is the setup you are looking for?

Thanks,

Abhinav T.
Applications Engineer
National Instruments

[yongster]

hmmm, that sounds like the setting i need

in any case i have attached another attachment

please help to see if this is correct and if this is what you mean

thks

regards

[Abhinav T]

Everything looks to be in order on this. I had one concern, what is the model number of your RTD? Is it a 2-wire, 3-wire or 4-wire RTD?

Abhinav

[yongster]

Thks

but to follow up i also have 2 concerns one related to the RTD

(1)RTD
for the RTD, we are actually using the properties of the fabricated metal using this equation (R = R0 (1 + TCR (T-T0)) which is integrated to  our chip as  a RTD, so for our case, can we use it as a 2 wire RTD?if so for the labview, we be reading data as temperature using RTD correct?

(2) For the heater, for the connections as shown previously, it seems that we are not able to control the individual heaters (i.e. the change in voltage supplied to the heater will be the same), i say if we want each heater individually to react to its respective temperature sensor (i.e. more fexibility, ), is it possible?

thks for the great support

[Abhinav T]

1) Your RTD should be fine as it is connected - you can confirm this using this Developer Zone document.
2) In order to control the heaters individually you will have to use the three outputs of the power supply individually (or use more power supplies). If you try to control each heater using only one output of the power supply, all you heaters will be tied to that one voltage.

Abhinav

[acanivell]

Nice post here, thanks for the info.

I am also planning to use for my thermal controller:

- PXI 4110 for heater drive.

- PXI 4351 for RTD interface (4-wires meas.!!), using the block terminal TBX-68T.

As I can read from your posts, one issue is unclear to my eyes:

- Do I need to supply excitation for my 4-wires measurement using PXI 4110?

[acanivell]

I just forgot to add this, in case my question is not clear enough:

I see that there are current excitation channels in 4351, but: 

I interpret from your drawings that you are wiring the heater drivers from 4110 through the 4351 terminal block TBX-68T. I thought this terminal block was intended to be used only for the 4351 module, for thermal readings, not for power output. 

That is why I am asking.