BACnet Explorer set the max master

Chipkin BACnet Explorer set the max master

This article explains how to change the Max Master value for BACnet MS/TP networks when using CAS BACnet Explorer (version 1.x). The Max Master setting controls the highest MAC address that the token-passing process will consider as a valid master device on the MS/TP network.

Adjusting this value can help optimize MS/TP network performance, particularly in installations where the number of master devices is known and fixed. Setting an appropriate Max Master value reduces unnecessary token passing to unused addresses.

To change the CAS BACnet Explorer (v1) MS/TP Max Master:

1) Open the settings file using a text editor (such as Notepad).
The settings file may be stored in one of the following locations:

C:\Users\<username>\Documents\CAS BACnet Explorer\Settings.xml
C:\Users\<username>\Documents\CAS BACnet Explorer (beta)\Settings.xml

2) Locate the iMSTPNmaxMaster parameter.

iMSTPNmaxMaster value="127"/>

3) Change the value to a number between 1 and 254.
Note: 255 (0xFF) is reserved for broadcast addresses and should not be used.

From the BACnet Specification:

This parameter represents the value of the Max_Master property of the node's Device object. The value of Max_Master specifies the highest allowable address for master nodes. The value of Max_Master shall be less than or equal to 127. If Max_Master is not writable in a node, its value shall be 127.

Note: This article applies only to version 1.xx of the CAS BACnet Explorer. Later versions may store configuration parameters differently or enforce limits automatically.