Disable NI-IMAQdx GigE Vision Discovery Broadcast Traffic

Issue Details

I am observing periodic UDP broadcast packets being sent from my system to address 255.255.255.255. These packets appear even when no vision application is actively running.

When using TestStand or other applications on systems with multiple network interfaces, I see a high volume of discovery messages being sent across all interfaces. If the device under test includes a switch or multiple network paths, it becomes flooded with these broadcasts and may begin missing valid commands during test execution.

Network captures (for example, Wireshark) show repeated DISCOVERY_CMD messages consistent with GigE Vision discovery traffic.

Solution

The NI-IMAQdx driver regularly sends a request via broadcast to address 255.255.255.255 for the automatic detection of new cameras within the framework of the GigE Vision Control Protocol (GVCP).

This broadcast is sent to all network adapters periodically every second without running any code, as long as the NI-IMAQdx driver (Vision Acquisition Software configuration support) is installed.

The only time the packets are not continuously transmitted is when only the NI-IMAQdx Runtime is installed (without configuration support). In that case, the discovery packet is sent only when calling IMAQdx Enumerate Cameras.vi.

To reduce or eliminate this behavior, use one of the following methods:

Disable automatic discovery using the Windows Registry

1. Open the Windows Registry Editor.
2. Navigate to the following path:
   
   

   Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\niimaqdxk\Parameters
   

3. Add a new DWORD (32-bit) value named DiscoveryTimeout and give it a value of 0.
   
   
   
   

4. Restart the Computer
5. Verify that broadcast traffic is no longer present.

Disable discovery on NI Real-Time systems

1. Add the following lines to the system configuration file:
   
   

   [IMAQDX]
   DiscoveryTimeout=0
   
   

2. Reboot the target

Block discovery traffic using Windows Firewall

Configure firewall rules to block UDP broadcast traffic associated with GigE Vision discovery.

Note: Use this approach when NI-IMAQdx must remain installed but discovery traffic should not reach external devices.

Remove NI-IMAQdx if vision functionality is not required

1. Using NI Package Manager, uninstall Vision Acquisition Software or NI-IMAQdx.
2. Restart the computer.
3. Verify that broadcast traffic is no longer present.

Additional Information

GigE Vision discovery uses UDP broadcast communication to detect devices on the network.

On systems with multiple network interfaces or switched network architectures, broadcast traffic can propagate across multiple paths, increasing network utilization and potentially interfering with time-sensitive communication.

Disabling the automatic discovery mechanism prevents cameras from appearing automatically in NI MAX. Manual discovery remains possible using IMAQdx Discover Ethernet Cameras.vi.