Excessive Max Master

Overview:

The "Excessive Max Master" diagnostic fails when the max master setting exceeds the last master on the OT network by more than 2. Reducing the max master setting not to exceed the last master by more than 2 will improve performance while allowing for future growth on the network. The actual performance improvement will vary according to the manufacturer's poll-for-master algorithm.

Causes

• Misconfigured Max Master: The max master default setting (127) has not been changed, or the max master setting has been configured to be >2 of the last master on the network.

Implications:

• Slow Communication: Every 50 token passing cycles, the master device must “poll-for-master” (PFM). A suboptimal max master setting will cause unnecessary PFM, slowing down communications on the network.
  
  

How to fix it:

Configure the max master setting to be no more than 2 above the last master device on the network.