Encoder simulation

[Nandopr]

Hello,

I have to simulate an encoder signal TTL 0-5V using LabView 7.1 and a DAQ NI USB 6008.

The encoder signal must have A and B signals with 90° of phase.

How can I do?

Thanks,

Nando

[Chuck_81]

Hello Nando,

you could do it using two counters, one generating the first output pulse train and another one generating a second pulse train with 90 degree phase delay. I verified that the 6008 has only one counter, and the digital I/O are static and not suitable for generating a continuous pulse train. You may use another 6008 board or select another device with better performances. A possible choice may be the NI USB-6210 

Hope this helps,

Fabio

[Buechsenschuetz]

We had a similar problem. The signal flow is just in the opposite direction but the basics are identical. We used a motor driver amplifier which was supposed to be fed with a two-phase signal (usually this feature is used to synchronize two or more motors by using the encoder of one motor to generate the drive signals for the second one). We found a device by a german manufacturer which generates a two-phase signal from a single phase input. The phase shift is fixed, i.e. will not be exactly 90 deg over the entire frequency range but usually the exact amount of phase shift does not matter. If this is the case with your application probably this hardware solution will help.

Of course you can try to build your own hardware solution by using a time-delay circuit which delays the original signal for a certain time. As long as the delay is not longer than the original pulse you will get something at least similar to a two-phase signal.