Encoder Simulation with cDAQ

[engineer1115]

Good day!

We want to simulate (generate) two A/B endocers by using cDAQ hardware. We have a cDAQ-9185 chassis and two NI-9474 modules to accomplish the task (or other modules if needed).

What would be the right apporach to achieve:

• Synchronized A/B signals which are 90° phase shifted
• Two A/B signal pairs are completely independent (frequency, activation)
• No side effects when changing parameters of one signal pair to the other signal pair.
• Voltage level: 24V | Max. output frequency: 100kHz 

Many thanks for your help!

[SteveD123]

For each of your encoders, can you not simply use a  CMOS 4019 inverter, a CMOS 4013 dual d-type flip flop and a level shifter to generate the A/B signals from an input clock running at twice the required output rate? The A signal changes state on the rising edge of the input clock, and the B signal changes state on the falling edge of the input clock.

You'd need to invert the clock signals if you want to simulate the encoder running backwards; this could be done with some extra gates.

This can then be driven from one of the 4 counter/timers on the cDAQ-9185.

Repeat for your second encoder channel.

[engineer1115]

Hi Steve

Thanks a lot for your suggestion!

I am sure that this would be a solution which works.

For our application, we would prefer an approach which does not require additional, external hardware, as the described encoder use case is just one example for the target application. There will be others with different requirements.

As we have selected a cDAQ module which is able to deal with 24V signals, we were hoping to accomplish the task with it.

Best Regards