rainer writes:
> I want to start two devices via serial port (RS232) synchroniously
> within a few microseconds(or even with an constant time delay).
> Therefore I send a carriage return to com1 and com2 using two
> serialwrite.vi within one case loop.
> But it seems that the time delay between the both carriage returns ar
> sent is sometimes longer, sometimes shorter.
> (The reason might also be that Windows NT is no realtime-system.)
> I there any possibility to trigger both serial ports, so that the
> carriage returns are sent with an constant time delay?
Rainer,
have you thought about using just one serial port? If your devices
have some form of address and you don't use handshaking, you can wire
a few devices in parallel.
Other ideas are c
onverters to from pc to RS485 (which is multidrop)
and 2 converters (with their own adress) back to RS232.
I always recommend using VISA for serial I/O. I assume that you have
some form of data dependency and delay between the serial writes.
Johannes Nieß
