Troubleshoot When NI CompactRIO Does Not Appear in Measurement & Automation Explorer (MAX)

There can be several reasons why an NI CompactRIO system does not appear under Remote Systems in Measurement & Automation Explorer (MAX), and most of them are network-related.

1. Try each of the following most common troubleshooting steps to recognize your system in MAX. If needed, see the bottom of this page for additional steps and details.
   1. Verify that the network cable is secure. On the CompactRIO controller, next to the network port, you should see one solid light and one blinking light indicating network activity
   2. Ensure that the DIP switches are in the OFF position and reboot the CompactRIO system if you make changes
   3. If you have multiple network adapters, such as a wireless Ethernet card, disable them
   4. Ensure that the CompactRIO system is connected to the same subnet as your computer
   5. Add MAX to the list of exceptions in your firewall software
2. After trying each of the suggestions above, select View»Refresh in MAX.
3. Once you see your CompactRIO system in MAX, select the appropriate option:
   1. I see my controller with an automatically assigned IP address (not 0.0.0.0)

1. I see an IP address of 0.0.0.0 and my CompactRIO system is connected to a network that automatically assigns IP addresses (has a DHCP server)

1. I see an IP address of 0.0.0.0 and my CompactRIO system is connected directly to my computer with a crossover cable or to a switch without a DHCP server

Additional Details and Troubleshooting Steps

After each attempt of the following steps, select View»Refresh in MAX to see if your controller appears under Remote Systems.

Check the status LED on the controller
1. If the light is repeatedly blinking once, it has an unconfigured IP address, and will either be 0.0.0.0 or link local, depending on the NI-RIO version you have. This is the desired state of your system for this point in the setup process. Try the other troubleshooting steps below.
2. If the light is not blinking, then your CompactRIO system has an IP address set up already. You should set the Reset IP DIP switch to ON and reboot the controller if you still do not see the target.
3. Refer to your CompactRIO controller operating instructions to determine what might be wrong with the system, or for a brief description of the blink codes, consult KnowlegeBase 3K5CTHQX: Why Is the Status Light on a CompactRIO Controller Flashing Continuously? 
Check that the network cable is secure on the target and host computer
1. If you are connecting directly from the host computer to the CompactRIO controller, make sure that you are using a crossover cable.
2. If connecting through the local network, verify that you are using a standard network cable (not a crossover cable). 
3. You should see two lights on the network cable connection, one solid and one rapidly blinking. This indicates that there is communication. If you see no blinking lights on the cable connection, make sure you are properly connected with the correct cable. 
If you have network firewalls enabled, try turning them off temporarily
1. Security software such as BlackICE can possibly block network communication to and from your CompactRIO controller.
2. On Windows computers, it is also possible that disabling the Windows firewall will not necessarily enable the blocked programs. In that case, you must explicitly enable MAX with the following steps:
   1. Windows XP
      1. Open the Network Connections Control Panel, located in Start»Settings»Network Connections; this will result in listing the local networks
      2. Right-click any connection and select Properties
      3. Select the Advanced tab
      4. Click Settings
      5. Select the Exceptions tab
      6. Click Add Program...
      7. Select Measurement & Automation in the list and click OK
      8. Click OK on both remaining windows
      9. Now MAX can communicate with your real-time controller
   2. Windows 7
      1. From the Control Panel, open Windows Firewall
      2. In the left-hand menu, select Allow a program or feature through Windows Firewall
      3. Click Change Settings
      4. Click Add another program…
      5. Click Browse… and browse to and select NIMax.exe located in the National Instruments directory (for example, C:\Program Files\National Instruments\MAX\NIMax.exe)
      6. Click OK
      7. Verify that Measurement & Automation Explore appears in the list and is selected to allow access
      8. Click OK and close remaining windows
      9. Now MAX can communicate with your real-time controller
3. National Instruments software uses Port 44525 for Ethernet target discovery. Make sure that this port is open to discover your CompactRIO system.
Make sure that the host and target controller are on the same subnet
If you have multiple network adapters (for example, wireless), be sure that all other network cards are disabled
1. When computers have multiple network cards, MAX may choose to look for remote devices through the card that your CompactRIO system is not connected to. This is very common on laptops, as the wireless device is often the primary network card.
2. If one card is wireless, be sure to disable it from the control panel, not just turn off the wireless antenna.
If you are using a CompactRIO system with multiple Ethernet ports, ensure that you are connecting the Ethernet cable to Port 1 and not Port 2
If you are using an intelligent switch on the network, make sure that it is not disabling a port that is routed to the target
1. Some intelligent switches that are used on a network will automatically disable some ports that could be blocking communication to the target from the host. 
Make sure that you have the correct version of NI-RIO installed on the host PC
1. If the software was recently upgraded, reinstall the NI-RIO driver.
2. New controllers require updated versions of NI-RIO; always make sure you have the newest version installed.

If after trying each of the suggestions above, you still do not see your CompactRIO system in MAX, refer to the operating instructions manual for your CompactRIO controller or contact NI.