Can DAQ USB 6001 digital output at 5V?

[feelsomoon]

Hi everyone,

I'm trying to use DAQ(USB 6001)'s digital output to drive a relay(RLY104) whose thresholds is from 2.7V to 5V. This relay is used to be driven by TTL 5V and works well. From the datasheet, 3.3V should also work but I failed.

I guess the problem may be the current. The maximum leakage current for DAQ is 0.8mA at 3.3V. And the input control signal current requirement for the relay at 2.7V is 0.78mA.

Our lab prefers not to add an additional amplifier or transistor because we need to connect DAQ to instruments and we want it to be more stable and not easy to be damaged. I'm asked to find a new DAQ which can turn on the relay. The problem is that I can't find any problems according to the manual. So I don't know what features our new DAQ should have.

I'm quite new with all the DAQ stuff. Could you guys give me some suggestions?

[crossrulz]

Do you have the digital lines configured to be active drive or open-collector?  If configured for Active Drive, it looks like everything should work just fine.  If setup as an Open-Collector, you will need to supply a pull-up resistor in order to get a voltage on your line.

[feelsomoon]

Thanks for your reply! I use it as an active drive since we want the circuit as simple as possible. I tried to measure the current through it by using a multimeter between the DIO pin and ground. And the current is super small. I'm not sure if this is normal for digital output.

[AnalogKid2DigitalMan]

Are you supplying power to the jack on the RLY104 board?

https://www.winford.com/download/rly104_datasheet.pdf

-AK2DM

[feelsomoon]

Yes, I did. I tried to use a power supply with 2.7V to turn on the relay connected to a valve and it succeeded. So I guess there is no problem with my relay.

Besides, I think to use a DAQ's digital output to turn on a relay then drive a valve should be a common and easy way in labs. Our lab is used to use a PCI card instead of DAQ to do so and always worked well. I wonder what other people deal with this problem.

[JÞB]

the 6001 just won't supply enough current to directly drive the relay. a 6509 device would be the correct replacement

[feelsomoon]

Thanks so much for your reply! The problem is that we need a multifunction I/O device not only one with DIO. I checked the specifications of the relay we use, which is RLY 104. I'm confused by Nominal relay coil current per activated relay and Input control signal current requirement. Which one is the requirement for the output from the DAQ?

I'm sure USB 6509's DO output at 24 mA and the PCI I/O device NI 6703 with 16 mA can turn on this relay. But most multifunction I/O USB models can't supply such a high DO current.

[nestorl]

The 6210 might be a viable option, as a voltage level of 2.7V corresponds to a -16mA current output for the DO. 

[JÞB]

Dup.post

[JÞB]

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@feelsomoon wrote:

Thanks so much for your reply! The problem is that we need a multifunction I/O device not only one with DIO. I checked the specifications of the relay we use, which is RLY 104. I'm confused by Nominal relay coil current per activated relay and Input control signal current requirement. Which one is the requirement for the output from the DAQ?

I'm sure USB 6509's DO output at 24 mA and the PCI I/O device NI 6703 with 16 mA can turn on this relay. But most multifunction I/O USB models can't supply such a high DO current.

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That is often the case!

Sometimes you need two devices that can do two special things