Running two different VI codes simultaneously

[Deep_End]

@crossrulz 

Thanks for the suggestions, I would require absoulte sychronization as the DAQ from both EMG, and the force plate would have to be simultaneous, but having said that, I will try the method that you have just suggested. 

Thanks

[johnsold]

Synchronizing the code does not do much. I think what you need to do is to synchronize the data from the two instruments.

Possibilities:

1. Generate a trigger pulse which causes both instruments to start acquiring data simultaneously. If the instruments have this capability, this method likely will synchronize the start of acquisition within microseconds.

2. Start one instrument from software timing. Use a hardware signal (such as Analog Start) generated by that instrument to trigger the other instrument. Again, if the instruments have the required capability, the synchronization will be very good.

3. Start both instruments with software timing (resulting in unknown delays between them). After both are running, generate a signal which will be measured by both instruments. Then align the data in software so the synchronizing signal marks a reference time in each dataset.

 Finding such a signal might be a challenge. The EMG appears to communicate via a wireless TCP/IP connection while the force plate uses RS-232. So you do not have ready access to the raw signals. A physical force signal which is applied simultaneously to the force plate and the muscle could work. Two small solenoids triggerend by a digital output pulse could apply a short force impulse to both the force plate and the muscle. How you control and power the solenoid at the muscle could be limited by your safety protocol and by the experimental protocol.

If the instruments are not too well shielded, you might be able to generate an electrical pulse close to both instruments which would appear in the data as a transient. This would not need to be connected directly to the subject or the force plate. But it might be difficult to get consistent results.

I have used this method on many experiments, although never on two instruments that really did not want to talk to each other.

Lynn