LabVIEW
serial connection still timing out
david wrote:
> hi, i have been trying to communicate with Labview through the serial
> port to a tektronix 3014 oscilloscope. using the serial communication
> example VIs provided by Labview 7.0 i keep getting a timeout error at
> the VISA read function. i did the loopback tests in both hyperterminal
> and labview and they both worked, but still i cant communicate with
> any device. does anyone have a VI that is already configured to
> communicate with this scope? or any advice as to where i might be
> going wrong?
Most probably message terminating. Serial port devices expect usually a
termination character to tell them that the command is finished before
they attempt to decode it and react accordingly. Hyper Terminal sends
the carriage return and/or line feed
which is generated by hitting the
return key to finish an entry without really showing this in a visible
way. So you may think that the return key just sends of the characters
previously typed in but it in fact also sends the according carriage
return character.
So in your LabVIEW example change the string display over its right
click context menu to show "'\' Codes Display". Then enter the string
you want to send and add a "\r", "\n", or "\r\n". One of the first two
should be enough, and then the instrument will probably start answering
with something.
Rolf Kalbermatter
> hi, i have been trying to communicate with Labview through the serial
> port to a tektronix 3014 oscilloscope. using the serial communication
> example VIs provided by Labview 7.0 i keep getting a timeout error at
> the VISA read function. i did the loopback tests in both hyperterminal
> and labview and they both worked, but still i cant communicate with
> any device. does anyone have a VI that is already configured to
> communicate with this scope? or any advice as to where i might be
> going wrong?
Most probably message terminating. Serial port devices expect usually a
termination character to tell them that the command is finished before
they attempt to decode it and react accordingly. Hyper Terminal sends
the carriage return and/or line feed
which is generated by hitting the
return key to finish an entry without really showing this in a visible
way. So you may think that the return key just sends of the characters
previously typed in but it in fact also sends the according carriage
return character.
So in your LabVIEW example change the string display over its right
click context menu to show "'\' Codes Display". Then enter the string
you want to send and add a "\r", "\n", or "\r\n". One of the first two
should be enough, and then the instrument will probably start answering
with something.
Rolf Kalbermatter
