Serial communication problems

[Johan, Sweden]

Hi
I use the System Exec.VI to open an external program "not written by me" that communicates thru the serial port to a device. My LabView program reads a log file that the external program creates and looks for the word end in it. This works fine mostly but once in a while i get the "Windows GetCommError" See attached file. The error message most come from the System Exec.VI or from Windows. What do you think ?
Software info:
Windows 2000 professional ver 5.00.2195 Service pack 4.
PC: Intel Pentium 4, Processor 1.6GHz, Primary memory 256MGb, 10GB Hd.
LabView ver 6.1
TestStand ver 2.0
VISA ver 2.5

Thank you!
//Johan

[vicky]

Hi,
This is a serial communication error and when there is a communication problem it pops up such errors,so i think the external program is creating the problem and notLV system exec.vi