Serial read problem in LV 7.1

[anacche]

I am reading a device with a rs232 interface 4800 baud 8/1/n/1 no handshake control

By a probe on bytes at serial port it says 600 - 700 bytes, but the instruction VISA read serial port, with the output of Bytes At Serial Port connected, returns 6-10 bytes and sometimes hangs.

Hyperterminal works correctly, bytes not read are in the serial buffer

anyone who can help me with some hints?

thanks

anacche

[crelf]

By a probe on bytes at serial port it says 600 - 700 bytes, but the instruction VISA read serial port, with the output of Bytes At Serial Port connected, returns 6-10 bytes and sometimes hangs.

Can you post your code or at least a screen shot so we can diagnose your issue?

[AnalogKid2DigitalMan]

Are you using the correct termination character upon read to correctly parse the data? The instrument manual should define what character(s) are required. Usually \r\n

[Donald]

VISA serial read terminates when one of following conditions is true

- there is a time-out

- the end-of-message character is found (default this is a linefeed)

- the requested number of bytes is available

I guess you should turn off the end-of-message character detection or redefine the character.

You shoud do this when you initialise the serial port (VISA config serial port.vi) or before the read action with a property node of class Serial Comm.

Good luck.

[anacche]

GOT IT!!!

It was the termination character!!!

Thanks... I used serial & visa before but this never happened.

Just setting it to "false" in VISA config serial port.vi solved the problem

Thanks a lot again

Massimo

VISA serial read terminates when one of following conditions is true

- there is a time-out

- the end-of-message character is found (default this is a linefeed)

- the requested number of bytes is available

I guess you should turn off the end-of-message character detection or redefine the character.

You shoud do this when you initialise the serial port (VISA config serial port.vi) or before the read action with a property node of class Serial Comm.

Good luck.