Adjusting SNE network sensitivity - Metasys - LIT-12013352 - M4-SNE10500-0 - M4-SNE10501-0 - M4-SNE11000-0 - M4-SNE11001-0 - M4-SNE110L0-0 - M4-SNE110L1-0 - M4-SNE22000-0 - M4-SNE22001-0 - Supervisory Device - SNE10 Network Engine - SNE11 Network Engine - SNE22 Network Engine - SNE Supervisory Network Engine - 12.0

SNE Commissioning Guide

Brand
Metasys
Product name
SNE10 Network Engine
SNE11 Network Engine
SNE22 Network Engine
SNE Supervisory Network Engine
Document type
Commissioning Guide
Document number
LIT-12013352
Version
12.0
Revision date
2022-12-12
Product status
Active
Language
English

About this task

Follow the steps in this section to adjust the network sensitivity of the BACnet/IP and MS/TP field bus networks for a network engine. By increasing the number of seconds the network engine waits before flagging a field device as offline, you can minimize the number of false offline reports. Three different sensitivity options, each with a different set of values, are available: high, medium, and low. The default setting for all network engines upgraded to Release 11.0 or later is medium.

The following are the three sensitivity range options and why you might choose them:
  • High Sensitivity: Use for critical applications or customer requirements for faster status updates
  • Medium Sensitivity (default): Use for a system that does not show any signs of offline cycling
  • Low Sensitivity: Use for a system that shows chronic occurrences of offline cycling
Note: If you adjust the communication parameters to low sensitivity, the following possible effects may occur:
  • Causes any outgoing confirmed messages to queue up for retries during the time when a remote device stops responding, but has not yet been detected as offline. For supervisory devices that are low on free memory, memory may become exhausted over time, which may cause the supervisory device to restart.
  • For an integrated general BACnet device, increases the possibility of missing a device restart. This scenario increases the chances of losing change of value (COV) subscriptions at remote devices for significant periods of time. In addition, commanded values might also be in unwanted states longer than normal.
  • For an integrated Johnson Controls-family device, increases the possibility that a slight delay may occur before a device restart is detected, requiring extra time to recover COV subscriptions and commanded values. Detection of the restart event is guaranteed, but old data is present longer than normal.

Do not specify an APDU Timeout or APDU Segment Timeout value that is higher than 30,000 ms, even though the system allows higher values.

Before you begin, verify that the engine is set to run in Expert Mode so that all attributes you need to adjust are available. For details, see Enabling Expert mode. Also, select the Advanced view for all attribute windows.

Note: Be consistent with the sensitivity adjustments. For example, if you select low sensitivity, make sure you use the low sensitivity values for all items.

Follow these steps to adjust the sensitivity values:

Procedure

  1. Open the Focus window for the network engine that you want to adjust. Enter new values for the sensitivity range that you selected using the values listed in Table 1. Figure 1 shows an example.
    Table 1. Supervisory Device Network Settings

    Attribute

    High Sensitivity

    Medium Sensitivity

    Low Sensitivity

    APDU Segment Timeout

    4000 ms

    10000 ms

    20000 ms

    APDU Timeout

    6000 ms

    10000 ms

    20000 ms

    APDU Retries

    4

    4

    5

    Internode Comm Timer
    Note: Older FxC controllers have a supervisory status module that times out unless the Internode Comm Timer is set to high sensitivity.

    20 seconds

    120 seconds

    240 seconds

    Figure 1. Example: Supervisory Device Network Settings
  2. Click Save.
  3. Open the Snapshot Focus window for the BACnet Protocol Eng integration of the network engine that you want to adjust. Enter the Poll Delay for the sensitivity range that you selected using the value listed in Table 2. Figure 2 shows an example.
    Table 2. BACnet Protocol Eng Network Settings

    Attribute

    High Sensitivity

    Medium Sensitivity

    Low Sensitivity

    Poll Delay

    20 seconds

    60 seconds

    120 seconds

    Figure 2. Example: BACnet Protocol Eng Network Settings
  4. Click Save.
  5. Open the Snapshot Focus window for the BACnet IP integration of the network engine that you want to adjust. Enter new values for the sensitivity range that you selected using the values listed in Table 3. Figure 3 shows an example.
    Table 3. BACnet IP Network Settings

    Attribute

    High Sensitivity

    Medium Sensitivity

    Low Sensitivity

    APDU Segment Timeout

    8000 ms

    11000 ms

    20000 ms

    APDU Timeout

    6000 ms

    12000 ms

    20000 ms

    APDU Retries

    3

    4

    5

    Internode Comm Timer

    30 seconds

    120 seconds

    240 seconds

    Figure 3. Example: BACnet IP Network Settings
  6. Click Save.
  7. Open the Snapshot Focus window for the integration of the network engine that you want to adjust. Enter new values for the sensitivity range that you selected using the values listed in Table 4. Figure 4 shows an example.
    Table 4. Field Bus MS/TP Network Settings

    Attribute

    High Sensitivity

    Medium Sensitivity

    Low Sensitivity

    APDU Segment Timeout

    6000 ms

    12000 ms

    30000 ms

    APDU Timeout

    8000 ms

    11000 ms

    29000 ms

    APDU Retries

    3

    3

    5

    Internode Comm Timer

    30 seconds

    120 seconds

    240 seconds

    Figure 4. Example: Field Bus MSTP Network Settings
  8. Click Save.
  9. Restart the network engine to put these new settings into effect.