VI_ERROR_IO while viMOVE operation on VXI-MXI-2

Question

Hello. We have troubles with our old PCI-MXI-2 & VXI-MXI-2 cards. OS WinXP SP3,  NI-VXI 3.6,  VISA 4.6.2
Any viMOVEOUT command, issued in A24 adress space, returns VI_ERROR_IO status. I read old posts on this forum and tried to turn off DMA mode for MXI-2. It helps to remove error status but all operations became very slow, inadmissible slow. I'd also tried to switch off SYNC MXI (in regedit set UseSyncMXI=0), but it doesnt solve problem with error status.
Could you ask me how to solve this problem, while not slowing down perfomance?
Thank you for attention.

Answer 1

ABV-
I found one other documented issue related to yours, and the solution was posted as a potential solution, but is not guaranteed to work.  It involves adjusting registry keys (which it looks like you are familiar with).  Caution should be taken when adjusting registry keys.  Again, this is just a step to try that helped one other customer out, so I thought I would offer it to you as a potential solution.
Some MITE-based systems have experienced problems with the MITE chip reaching the maximum number of retries on the PCI bus. To help prevent this problem from occuring, a delay was added before the MITE chip would perform a retry on the PCI bus. The amount of time that the MITE waits is determined by the DmaCpuRequestDelay value that is entered in the Registry. The default value for this setting is 2.
In this instance, it was this value that was causing the slowdown in the transfer rate. By changing the DmaCpuRequestDelay to 0, the transfer was increased to an acceptable level. However, caution should be taken when changing this value. If this value is changed, there is a slight possibility that bus errors might be received during large data transfers, due to the maximum retry limit being reached on the MITE chip.
If this happens, there are two options:
You can raise the DmaCpuRequestDelay up to 1 or back to 2
You can disable DMA on the MITE chip by changing the DisableMiteDma value to 1.
To change the DmaCpuRequestDelay, use the Registry Editor via Start » Run and type regedit. Navigate to the following section of the registry for WIN32: HKEY_LOCAL_MACHINE/Software/National Instruments/NI-VXI
     I hope this helps.  Have great day!
Gary P.
Applications Engineer
National Instruments
Visit ni.com/gettingstarted for step-by-step help in setting up your system.