On some busy building networks, equipment controllers on the BACnet/IP and MS/TP field bus may cycle online and offline to the NAE , even though the device is actually online. This behavior is most often seen with small-capacity network engines. If the building network is experiencing this issue, you can lower the sensitivity of the BACnet/IP and MS/TP field bus networks by increasing the number of seconds the network engine waits before flagging an equipment controller as offline. Three different sensitivity options, each with a different set of values, are available:
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High Sensitivity: for a system that is not showing any signs of the offline cycling issue
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Medium Sensitivity (default): for a system that is showing the offline cycling issue occasionally
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Low Sensitivity: for a system that is showing chronic occurrences of the offline cycling issue
Table 1 lists the items in the network engine that you can adjust to decrease network sensitivity. After changing any of these values, you need to restart the engine for the new sensitivity settings to take effect. For a description of the steps required, see Adjusting NAE network sensitivity.
|
Navigational Tree Item |
Attributes to Adjust |
|---|---|
|
Network Engine: Focus window (See Table 1) |
APDU Segment Timeout APDU Timeout APDU Retries Internode Comm Timer |
|
BACnet Protocol Eng (See Table 2) |
Poll Delay |
|
BACnet IP (See Table 3) |
Internode Comm Timer APDU Segment Timeout APDU Timeout APDU Retries |
|
Field Bus MSTP (See Table 4) |
Internode Comm Timer APDU Segment Timeout APDU Timeout APDU Retries |