Unable to read value at RS232 port.

[GerdW]

Hi govindsankar,

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@govindsankar wrote:

Can you tell me what you mean by communication protocol. Can you give me an example. Because I know my the microcontroller communicated using RS232 serial ports and RS485 ports plus the switching matrix with NI chasis PXIe1078. So what else does it mean by communication protocol or what data is available in communication protocol.

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"Communication protocol" not only covers the hardware (which devices, which ports/connections) in your setup. A "protocol" also describes the/certain "software layers": which messages are sent, how are the messages formatted, which kind of responses for which kind of commands, any special port settings (baudrate, etc.), and a lot more…

[govindsankar]

Okay thank you. So isnt it same as VISA Configure Serial Port, i.e configure baud rate, data bits, parity, stop bits and flow control. Other than that I know that it is connected to the Com Port 4 of the PXI 8430 RS232 of the PXIe Chassis 1078. Baud Rate is 115200, 8 bits, parity is none and flow control is none. The devices are the microntroller - RS232 - NI PXIe Chassis 1078. Is this all? 

[billko]

Setting up the hardware is only half of the job.  The other job is to know what the instrument on the other side needs to communicate with you.  The closest analogy I can come up with is you've established that you want to communicate by telephone with someone, and now you have to agree to what language you are going to use to talk to each other.  It's not a perfect analogy, but hopefully you can understand what the next step is.