Instrument Control (GPIB, Serial, VISA, IVI)
RTS in 232
I've already posted, but....
Hi people,
I already posted something like this, but not specific, so here I am again!
I have 2 PC (1 ps and 1 Fieldpoint, no matter this...), and I make them communicate via 2 modems, base band.
When I want to send (VISA write) some characters to the other PC, I have to set RTS signal ON (to make a request to send to the modem). Modem answer with a CTS signal, and then I write characters. This works, and the other PC correctly receive data.
The problem is when I reset RTS (RTS = 0), to deactivate the carrier signal. Because carrier can't stand on communication line. If carrier is always present, the other PC can't initiate a communication!
When I put RTS = 0, the second PC receives "framing errors", and print faulty characters. Why so? Is there another way to do what I'm aiming to do?
I expected the driver to automatically sitch on RTS when I want to send data, and automatially switch off RTS when data are transmitted, (flow control:RTS/CTS), but it doesn't work! Carrier signal stay on!!!! So I'm forced to set and reset RTS programmatically......
Help will be really appreciated!
graziano
Hi people,
I already posted something like this, but not specific, so here I am again!
I have 2 PC (1 ps and 1 Fieldpoint, no matter this...), and I make them communicate via 2 modems, base band.
When I want to send (VISA write) some characters to the other PC, I have to set RTS signal ON (to make a request to send to the modem). Modem answer with a CTS signal, and then I write characters. This works, and the other PC correctly receive data.
The problem is when I reset RTS (RTS = 0), to deactivate the carrier signal. Because carrier can't stand on communication line. If carrier is always present, the other PC can't initiate a communication!
When I put RTS = 0, the second PC receives "framing errors", and print faulty characters. Why so? Is there another way to do what I'm aiming to do?
I expected the driver to automatically sitch on RTS when I want to send data, and automatially switch off RTS when data are transmitted, (flow control:RTS/CTS), but it doesn't work! Carrier signal stay on!!!! So I'm forced to set and reset RTS programmatically......
Help will be really appreciated!
graziano
