DIO on NI622X

[huygens]

Hi,

I'm dealing with a NI6221 PCI board within a brushless control application.

So far I've not been able to get plenty of informations about the input/output stages of the board.

Outputs look to be equipped with a weak pull-down resistor, is it installed on a pnp-open-collector out?

I have to connect these outputs to motor drive's inputs and they require at least 100mA each one, therefore I'll have to adopt a interfacing board with relays or other, more current sinking/sourcing, stages with respect to the ones provided on the NI6221. Does NI provide any sort of interfacing boards (with external power supply) for these higher-current demanding applications? Otherwise I'd need to mae it myself.

Thanks in advance

[Hudson]

Hi huygens,

As stated at page 6 of the NI 622x Specifications manual [http://www.ni.com/pdf/manuals/371290g.pdf], Digital I/O stages resistors are pull-down type but unfortunately there are not specific informations on hardware components.

The best I can do is address you to the DAQ M Series User Manual you can find here: [http://www.ni.com/pdf/manuals/371022h.pdf].

May be from here you can find some informations that drive you to the conclusion on which kind of hardware is present.

I will suggest you to observe figure 6-1; page 6-7 Programmable Power-Up States bulleted list; and figure 6-4.

In my opinion it isn't a simple pnp-open-collector out...

As regarding your second question, NI doesn't provide any sort of interfacing boards for the high-current demanding application you require. 

I hope to have provide you some help

I wish you a good day 

[JB]

Here is how I usually do this.



This wiring offers an optical isolation between the expensive DAQ interface and the power driver. A DO can sink/source at least 16mA (see page 7 on this document) and would be able to drive the photocoupler. Therefore, you could simplify the circuit by removing R6, R7, C6 and T1.

Message Edité par JB le 09-07-2007 02:37 PM