solenoid triggering using M series multifxn DAQ, BNC block, and external power source

[bacchussr]

I need to trigger 3 separate solenoids: should I use the digital or analog outputs.  In this case, timing down to 5 or 10 msecs is crucial.  I am also wondering how I should handle the voltage spike that occurs when the magnetic field of the solenoid collapses.  Would a diode across the solenoid terminals solve this problem? 

Thanks

Steve

[Stuart_G]

Can't help you with the voltage spike issue, but I would say the easiest way to fire the three solenoids is going to be using digital outputs.  If you need to time these then you have a couple of options. 

#1.  Use the timed loop to setup up your timing.  It is accurate to the rates you specified.

#2.  By an M series board with correlated digital and use a counter or some external clock to take care of the timing for you.  This would be a HW timed method so your accuracy and jitter would be improved with the tradeoff that the programming would be slightly more difficult and you need to provide the HW clock in some fashion.

StuartG

[JordanRandall]

Hi Steve,

Stuart mentioned some interesting points to consider. I would also add that if you are to choose digital outputs you may need additional relays to trigger the solenoids because digital lines have minimal current. Do you have the datasheets on your solenoids? What is the minimum current requirement to trigger the solenoid?

Furthermore, to mitigate the voltage spikes you could try using an RC snubber circuit that suppresses any rapid rise in voltage. This circuit consists of a capacitor in series with a resistor across the solenoid terminals.

We also have numerous signal conditioning modules that specifically handle this type of application. If you would like to post your email I could send you some additional information on system configurations.  

Post a message I you need any additional information,