>1. Program Capture unit for event on rising edge >2. Capture rising edge >3. Program unit for event on falling edge >4. Capture falling edge >5. Program unit for event on raising edge >6. Capture rising edge >7. Do some calculations Yes, I've used it to measure both frame rate and positive or negative pulse widths all at the same time. Andy ================================================================== Andy Kunz - Statistical Research, Inc. - Westfield, New Jersey USA ==================================================================