I have a high speed application wherein I use handshaking to read data from a device. The REQ pulses sent by the device to the DAQ board (an AT-DIO-32F) are TTL high .5 microsecond duration square pulses. These signals are currently capable of triggering the computer, so I can get the data I need. However, the device does not want to accept the ACK pulses for some reason. Whenever I try to use them, the device just sits and won't send data. My question is, can the board read the data fast enough to make the ACK pulses irrelevant? The device waits another .5 microseconds after the END of the REQ pulse before it starts looking for more data and latch to the buffer. If the DAQ board can read within the first .5 microseconds while the REQ signal is still high, the device will keep the data on the buffer, guaranteed....or as guaranteed as it gets. 🙂 In the manual for the board it says "REQ to DRDY in leading edge mode" is a maximum of 225 ns. Then it says "start of read or write to DRDY inactive" maximum 240 ns. They never say how long it is from the beginning of DRDY to the read or write, though. The only other piece of information that seems to address this is "input data valid after REQ" must be at least 120 ns. From how I interpret it, it seems like it could take a maximum of about 620 ns. Does anyone out there have experience with exactly how long it takes to read the data? I am not exactly sure how to read the timing diagram. If it reads within that microsecond, I don't even really need the ACK pulse for the device, because it waits on it's own for that microsecond. Thank you.