Transmit single pulse

[jwsin]

Hi. I'd like to transmit a single pulse (for example, a single byte 0xFF) via RS-232 to serve as a "request to send" signal for a PIC microcontroller. Then, the PIC will send its data to LabView. I'm using VISA read and write from the example Basic_Serial_Read_Write VI. I have the "read" part working, but don't know how to configure the VISA Write to transmit the single pulse, then immediately read the incoming data.

Please advise. Thanks!

Jennifer

[Shawn B.]

Jennifer,

You can send a single byte by sending a single character with a VISA Write. For example writing "A" would send 0x41. You can also right click on the string control and select HEX display to manually type 0xFF.

You mentioned that you want to send a "single pulse". You can send a byte like I described above, but serial communication sends one bit at a time (serial) so you will actually be sending 8 pulses (actually there are start and stop bits as well so 8+) for every byte. Just wanted to make sure this was understood.

Shawn B.
National Instruments