Instrument Control (GPIB, Serial, VISA, IVI)

cancel
Showing results for 
Search instead for 
Did you mean: 

Changing processor speed causes system to reboot when GPIB driver accessed

We are using v2.5 of the NI-488.2 driver and communicating with the instruments using a GPIB-ENET interface.  The software is running in a virtual machine (VM) on a server.  The installed operating system is Windows XP.  Everything works fine until we change the CPU resource allocation to try to balance the load on the server.  When we reduce the available CPU, the VM reboots on a GPIB call. 
 
Is there a minimum system requirement (minimum CPU) for the NI-488.2 driver?
 
Is there some speed dependence which might cause problems as effective or available processor speed changes, as in when the CPU resources are scaled by a VM or when the CPU speed changes in response to power management control?
 
Anyone have any ideas?
0 Kudos
Message 1 of 4
(4,256 Views)
Hi mnecaise,

I'm looking into this right now. Using NI-488.2 in Virtual Machines is not something that has been fully tested right now and I would like to replicate this over here on our side. Could you please give us more specs of your system? E.g. Which software are you using for virtual machine, what the specs are of your server, etc.

Please give me as much information as is possible so that I can work on this. Thanks!


Rasheel
0 Kudos
Message 2 of 4
(4,233 Views)


I'm looking into this right now. Using NI-488.2 in Virtual Machines is not something that has been fully tested right now


OK, So, I know I'm on the bleeding edge... 
 
Server is an HP Proliant DL380 with 1 Xeon E5345 2.33 GHz 4 core processor.  Hyperthreading disabled.  14GB RAM.  949.25GB RAID 5 Disk array.
 
Running VMWare ESX on bare metal.   VM image has Windows XP installed in 15GB virtual disk.  Allocated 512MB RAM with unlimited CPU.  Has three virtual network interfaces enabled in this image.  1 for intranet server access, 1 for subnet containing product under test, 1 for subnet containing instrumentation (gpib-enet, serial server, etc.). 
 
There are currently only two (yes 2) users on this machine.  We are in an early state of implementation; and, expect to have 20-40 users on the server eventually. 
 
We have a GPIB-ENET connected to same switch as Bosonova thin client and serial server.  Connection to server is via D-Link wireless bridge which has a good 54Mbit connection to building wi-fi infrastructure.  Infrastructure backhaul from Xirrus wi-fi array to server is 1 Gbit. 
 
Everything works fine as long as we don't try to throttle the CPU allocation for the session.  We're running some legacy code that, shall we say, isn't very thrifty in it's utilization of CPU.  As a result, we need to throttle the session so it doesn't eat up all the CPU cycles on the core it's running on, limiting available resources to other sessions.   The problem occurs when we try to do this, limiting the allocated CPU resources.  Prior to running the test, we set the resource allocation and restarted the VM with the new settings.  The session (Windows) appeared to be functioning correctly in that we could run programs that did not use the GPIB interface.    When starting our test application, the VM crashes and reboots on a GPIB function call.  The problem is repeatable.  It goes away when the VM is restored to unlimited CPU.  The last CPU setting we tried was 600MHz equivalent (limit to maximum of 25% of one core)   
0 Kudos
Message 3 of 4
(4,225 Views)
Wow okay. Thanks for the detail. I'll run the NI-488.2 drivers on a VM on my end and run some tests to see how it behaves.
Rasheel
0 Kudos
Message 4 of 4
(4,209 Views)