Destination Host Unreachable Error When Pinging Real-Time PXl Controller

Updated Apr 5, 2023

Reported In

Hardware

  • PXI Controller

Software

  • LabVIEW Real-Time Module
  • Measurement & Automation Explorer (MAX)

Issue Details

I am having trouble to access the NI PXle-8840 Real-Time controller from my computer. No device is listed in the Remote Systems menu of NI MAX app. I have tried to ping the IP address of the controller but the result showed, "Destination host unreachable". 

Solution

If any network limitation prevents NI MAX accessing to the PXI, then you should connect a computer directly to the PXI using a normal Ethernet cable. 

Note: You just need a normal patch cable, there is no need to use a crossover cable because the NICs on your computer and on the controller should perform the Automatic Crossover detection. 

  1. First, change the IP address of your computer, in order to be on the same subnet of the RT Controller. So, for example, at the moment your RT controller has the IP 169.254.219.159, set the IP of your computer to 169.254.219.1. Make sure to define the subnet mask as 255.255.0.0.

  2. Then, connect the two devices using an Ethernet cable. At this point, you should be able to ping the RT Controller from your PC.

  3.  Finally, open NI-MAX > Remote Systems. The software should not show anything yet, so right-click on that and choose "Create New". Then choose “Remote Device (not on the local subnet)”. Indicate the IP of your RT controller. 

 If it works, you should see the controller under Remote Systems. You can then click on the Network Settings and change the IP address of your controller to Static and possibly assigning an IP address in the same subnet of your  server.

Once done, the controller restarts. You can disconnect the cable, connected the LAN cable, and check if the IP is the right one.  
 

Additional Information

By default, the PXI is configured as “DHCP or Link-Local”. Consequently, it tries to get an IP address from the DHCP server. If for any reason the DHCP server cannot allocate an IP, the RT Controller will have a Link-Local IP address, in the standard form of 169.254.xxx.xxx. 
This is a temporary address that you need to change. Possibly with a Static IP address. 
The easiest way to do this is to manually add the device in NI MAX, selecting "Create New" from "Remote Systems".
Please follow the steps in Real-Time PXI System Initial Configuration and Software Installation  for more guidance.