Slow READ response from ENET-232/4

[Garth]

I have a 1 GHz Pentium 3 PC runing Win 2000. I believe it's up to date on service packs. My LabWindows CVI 6.0 app talks to an ENET-485/4, a GPIB-ENET/100 and an ENET-232/4. Reads & writes from/to the GPIB-ENET and the 485/4 are fast, but reads from the 232/4 are slow - sometimes as long as 5 seconds. The only GPIB device it's talking to is an HP EPM-442A two-channel power meter, and I KNOW that meter can produce a couple of readings per second over GPIB.

Here's the odd thing - this same problem used to afflict the ENET-485/4 until I added the ENET-232/4 virtual ports to the PC. Now the 485 reads are fast and the 232/4 is the dog.

Has anyone else has this problem? G. Arthur

[Randy Solomonson]

Hello-

Does this application use VISA? If not try using the non-VISA serial API. Otherwise, try VISA. Is it possible to get an NI-Spy capture of the VISA calls? sysinternals.com has portmon and tdimon that monitor the serial port and ethernet port respectively. Would it be possible to attach output from these utilities?

Randy Solomonson
Application Engineer
National Instruments