VISA Serial Communication Problem

[T Taulbee]

Serial Communication Problem

Hopefully someone can help.  I am trying to use Labview to send commands and receive information from a Ludl Electronics MAC-2000 microscope stage.  I am trying to use the example Basic Serial Read and Write VI.  I know that my serial port is working because I have conducted a loop test by shorting pins 2 and 3 on the 9 pin connector.  What I type in the “string to write” window matches the “read string” window.  I know the microscope stage works because when I type commands into Windows HyperTerminal, the stage responds appropriately.  However when I type the same commands into Labview (string to write), and run the VI, nothing happens (the microscope stage doesn’t respond).  The program simply times out.  I checked the return count of the VISA Write, and I get the correct count of bytes “written”, but the microscope stage doesn’t respond.  I think there is a handshake problem with Labview since HyperTerminal works, but I don’t know what the problem is.  Any help would be greatly appreciated. 

Thanks,

Tim Taulbee

[T Taulbee]

Dennis Knutson solved this problem in another post on Serial Communication.  My problem was that when I typed a commaned, the end of the string had a \n (linefeed) where the instrument was looking for a \r (Carrage return). 

Thanks again Dennis!

Tim