Telnet read problem -- Telnet read back

[plai]

I am trying to use telnet to send TL1 command to my UUT and expect to read back measurement data.  I was able to read proper data once in a while but most of the time I read back the TL1 command that I sent.  I tried different read mode and timeout period but nothing seem to matter.  My vi was written in Labview 8.2.1 with Internet toolkit.  I read in the forum about some limitation of the telnet read problem of the vi from the internet toolkit,  Is there any better read driver around?

Thanks,

Patrick 

[Daniel_E]

Hey!  I have a few questions for you that should help us solve this problem.  First, have you tried out the telnet shipping example "Telnet Line Client.vi".  This will help us minimize programming errors, etc.  Also, what type of device are you trying to communicate with?  Are there other forms of communication available?  For example, does the device also have a serial port, GPIB Port, etc.?  Also, is it possible to write to the device using TCP/IP (This is what telnet is based on)?  Let me know the answers to these questions and I will be better equipped to help you out!!

Thanks!

Dan

[plai]

I have tried the Telnet Line Client.vi.  It is working fine but I want to be able to control with my device automatically rather than using a user interface.  The device unit test is one of our product that support TL1 commands through telnet intercace and it is my only option.  In fact, I was able to send commands and read back what's return most of the time, but the read back is so unstable that nothing will get return once in a while.  I have to restart the .vi for it to work.  I have done this write and read operation with RS232 before and I never encounter this type of problem

Thanks,

Patrick

[Daniel_E]

So, if the example works, is it possible to build your program from that?  What is different from your VI to the example?

[plai]

I was able to build a RW module from the example that is somewhat working, but it seems like once in a while it will not return anything (especially if I let it runs overnight).  I have to re-boot my Labview and it will recover again...