Can I use a NI-USB 6343 as a grounded input to trigger an injector?

[Brown@KTR]

Hello forum members,

I would like to be able to fire a high speed solenoid valve (low impedance approx 1.6ohm) using a peak and hold injector driver (from AEM).  The output from the P&H driver is activated when the input trigger is grounded.  Can I use the 6343 to provide this grounded trigger?  I read somewhere in the manual that I might be able to use a PFI or DIO line as an output driving a 0.  Is this what i'm looking for?

Thanks in advance,

-Mike    

[Leah-L]

brown_ktr,

I think the 6343 should work for you. You can use a digital output from the DAQ as your trigger.

Leah

[Brown@KTR]

Leah,

Thank you for your reply. I was just going through DAQmx Help in LabVIEW and I read that I can't set the DO driver type to open collector on the 6343.  Therefore, I would have to be driving from a logic HI state to a logic LOW state (ground).  Ideally, I think that I want to be driving from a tri-state to a logic LOW state (ground).  This way the inputs on the Peak & Hold Injector Driver won't see the HI state, only the ground.  I'm trying to get in touch with a technician at the company right now.

If you stil think that this should work with the 6343 could you please try to explain how to configure the trigger in LabVIEW? Would it be enough to set the "invert lines" channel property to true so that when I enable the trigger it drives the output to 0V?  

Regards,

Mike 

[Leah-L]

brown_ktr,

Let me make sure I understand your application. Instead of toggling between a logic High and a logic Low on your digital outputs, you want to switch between a ground and a high impedance state?

Leah

[Brown@KTR]

Leah,

Yes, essentially.  Switch between a ground and a high impedance state (driver off).  The Peak & Hold Injector Driver fires an injector when the input is sent to ground (from an off state). Please see attachment...when INJ1 (on the input side) is grounded, 12V is sent to the output side to fire INJ1 (on the output side).

Sorry for the confusion.

-Mike 

[Leah-L]

Thanks for the clarification! Do you happen to have the model number for the injector driver so that I can take a look at the spec sheet?

Leah

[Brown@KTR]

These were the instructions that came with the unit.

http://www.aemelectronics.com/Images/Products/Installation%20Instructions%2030-2710.pdf

Thanks,

Mike

[johnsold · Accepted solution]

Mike,

On the second page of the document it says: Trigger Impedance: 220 ohm input impedance, pulled to 12 V (60 mA draw).

IF YOU CONNECT THIS TO A DIO LINE, YOU WILL DAMAGE THE USB-6343!

What you want is a driver like the ULN200x series of ICs.  They can handle the 12 V and the 60 mA. Inverting versons are available so that a logic high from the DIO line will ground the input to the injector driver.

Lynn

[Leah-L]

I have to agree with Lynn on this one. Our DAQ cards aren't designed to handle that much current and you will damage the card. Thanks, Lynn, for the recommendation for the ULN200x. 

Leah

[Brown@KTR]

Thank you both for your help and quick replies.

Cheers,

Mike