Never eventually did it. Was just a thought. I think it would depend on what you've got for a controller (defines the signal width) and what is the max step pulse frequency. Modern PLCs can have scan times in the range of 0.1mS. My feeling is it could be not enough if you have high frequency step signal. But you could do simple math calculation to determine.
Another option could be an Arduino type microcontroller, which has much faster processors. The fastest I have seen from Arduino is 84Mhz. I think it should easily accomplish the task if you program it correctly.
Dan