NI-9265 maximum load for 1mA output

[Cryofree]

I am using NI-9265. On the web, it is mentioning that; it has a 600 ohm maximum load capacity. I will use this card to supply 1 mA excitation current for our serial connected RTDs. they will have totally 1100 ohm resistance. So my question is can I use this NI-9265 card to supply 1mA current with 12V input voltage from a DC power supply? And what is this maximum load 600 ohm capacity? Is it for the whole card or just for 1 channel? And what is your suggestion for my RTDs' connection? Do I need to use an additional channel to divide loads?

[santo_13]

Wait, why are you using this just as a power source for your RTD? what instrument measures the RTD?

[Cryofree]

yes just to apply 1 mA current to the PT-103 temperature sensors

[Cryofree]

I am also using NI-9238 for voltage measurement. With a code with a calibration curve, we can read the temperature accordingly.

[santo_13]

You're making up for the right instrument using two separate cards, which I would not recommend.

In any case, to answer your original question, can 9265 drive 1mA into 1100 ohm load, yes. Given the compliance voltage is 12V max, the maximum load at any current is given by V=I*R , 12V / 1mA = 1200 ohm.

[Cryofree]

So, can I use the same load with a supplied 24V for an additional channel to get another 1 mA current output?

[Cryofree]

I mean, I have 1 mA for 1100 ohm on a channel. And if I want to use another channel for another 1100 ohm with 1 mA, is it enough to supply 24 volt from the external power supply? In general, individual 2 loads with 1100 ohm resistance and 1 mA for each load does this work with supplied 24V?

[santo_13 · Accepted solution]

You can use an 1100-ohm load on each of the channels at 1mA each with just a single 24V supply.

[Cryofree · Accepted solution]

thank you for your reply.