​Problem:

A dealer has an installation where the NetLinx master will fall off-line in regards to the network. The master will lose Studio connection via Ethernet, then pages are not accessible; and other network functions are locked out.

While trying to trouble shoot this problem, they noticed a new command that was added to build 85 of the NetLinx firmware. The command is:

"set udp bc rate"

This command allows the udp broadcast rate to be changed. They set the UDP broadcast rate to 0, and all of the connection problems went away.

• Other than the obvious description of what this command does, what is this for?
• Do we need UDP in the average system?
• Does it hurt to turn it off?
• What do we lose when it is off?
• Should the default rate be 0, rather than 5, which is the current default?

Response:

The UDP broadcast has been part of the NetLinx from the beginning. We recently added a feature to the G4panels that uses this function. The NetLinx master uses the broadcast to find touch panels set to the 'Auto Connect' mode. This is expected to be a rarely used feature, as most systems will use either static or DHCP IP addresses, when connecting via Ethernet.

Setting the 'udp BC rate' to zero should not have had an effect on connectivity to the master. However, there may be some network settings on this customer's network that makes the UDP broadcast a problem.

The average system does not need UDP. It is used only if 'Auto Connect' is used. Setting this to zero does not affect any other networking process. The only thing that you lose is the Auto Connect on G4 panels.

The Default should not be zero because of the potential need for it on G4. However, it should be noted that this could be a problem on some networks, and setting the rate to zero maybe be required. On those networks, the Auto Connect feature will likely not work in any case.