SA Bus Integration Attributes - Metasys - LIT-1201793 - Software Application - Site Management Portal - 12.0.50

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Brand
Metasys
Product name
Site Management Portal
Document type
User Guide
Document number
LIT-1201793
Version
12.0.50
Revision date
2023-06-02
Language
English

The SA Bus Integration object contains attributes common to many Metasys system objects. You can find a description of these common attributes in the Common Object Attributes section. This section includes attributes of the Focus/Configuration, Provisioning, and Diagnostics tabs.

Note: In the Notes column, attributes that are marked with a letter C are configurable, attributes marked with the letter W are writable, and attributes marked with the letter N indicate values not required.
Table 1. SA Bus Integration Attributes - Focus/Configuration Tab

Attribute Name

Notes

Description

Alarm State

 

Indicates the current status of the object. The expected state is Normal.

Object Name

C, W

Identifies a name for the SA Bus object.

Object Identifier

 

Specifies an internal identifier assigned to the SA Bus.

Username is BACnet Object Name

C, W

Controls whether the object’s User Name attribute is also the Object Name attribute. The Object Name attribute is not writable, so the only way to change the Object Name attribute is to edit the User Name attribute and set the User Name Is BACnet Obj Name attribute to True.

Version

 

Specifies the version number for the SA Bus.

Table 2. SA Bus Integration Attributes - Provisioning Tab

Attribute Name

Description

Provisioning Status

Lists the current status of equipment controllers defined on the SA Bus of an SNC. Information presented includes Model, Address, System Status, State, and Progress. When the SNC application is started, the System Status changes from Instances Deleted to Operational. The System Status attribute is polled once every 60 seconds, so a refresh in status may not be immediate.

Provisioning Files

Lists the current status of provisioned files for the equipment controllers defined on the SA Bus of an SNC. Information presented includes Model, Address, File Name, Current Version, Staged Version, and Available Version.

Table 3. SA Bus Integration Attributes - Diagnostic Tab

Attribute Name

Description

Active Baud Rate

Displays the actual data rate on the wire for transmitting and receiving. When set to Auto, the port is waiting to synchronize with the network.

Broadcast Receive Rate

Indicates the number of BACnet broadcast messages received on the MS/TP field bus network of the device in the last minute. If this number is high, the performance of the specific MS/TP field bus network is affected by broadcast receive traffic.

Broadcast Receives

Indicates the number of broadcast messages received.

Broadcast Transmit Rate

Indicates the number of BACnet broadcast messages transmitted on the MS/TP field bus network for the device in the last minute. If this number is high, the performance for the specific MS/TP field bus network is affected by broadcast transmit traffic.

Broadcast Transmits

Indicates the number of broadcast message transmissions.

Buffer Overflows

Indicates the number of data frames lost at this MS/TP device because there was no buffer available to which to save it. This number includes outgoing and incoming messages.

Bus Analysis Date

Displays the date when the last full MS/TP field bus scan finished. The Analyze Field Bus command initiates the network scan.

Bus Analysis Time

Displays the time when the last full MS/TP field bus scan finished. The Analyze Field Bus command initiates the network scan.

Bus Analysis Progress

Indicates the progress of the full MS/TP field bus scan initiated by the Analyze Field Bus command.

Bus Device Configuration List

Lists MS/TP devices that either have been detected on the SA Bus or have been configured on field devices existing under the MS/TP Field Bus Integration Object.

The Bus Device Configuration List provides configuration information for each device, including which devices are responding, which devices may have been configured incorrectly, and the addresses of all devices. Only bus supervisor devices provide all this information. This object creates the list when you issue an Analyze Field Bus command.

Bus Health Index

Indicates the overall health of the MS/TP field bus based on the number of errors occurring at the network engine. The most desirable value is 0. The higher the number, the worse the bus health/higher the number of errors. The Bus Health Index is re-evaluated every 30 seconds and gradually returns to zero if no new errors occur.

This object derives the value for the Bus Health Index from periodically reading the Header CRC Errors, Data CRC Errors, Framing Errors, and Lost Token attribute values to create a moving average of total errors. The Weighted Bus Health Constant attribute determines the responsiveness of the Bus Health Index.

Bus Performance Index

Indicates the responsiveness of the bus supervisor device on the MS/TP field bus. The most desirable value is 1. Values from 2.5 to 6 are marginal and updates to devices on the bus may be slow. If the value is greater than 6, the performance is poor and may indicate offline conditions.

The device derives the value for the Bus Performance Index by comparing the measured token loop time at the network engine and the predicted token loop time calculated when the MS/TP Field Bus Integration object is first created or when the network engine device count changes. This object uses the difference as input for determining the weighted moving average of the token loop time. The Weighted Bus Performance Constant attribute determines the responsiveness of the Bus Performance Index.

Bytes In

Indicates the number of data bytes received by this device. This number includes all messages from all devices.

Bytes Out

Indicates the number of data bytes sent by this device. This number includes all messages to all devices.

Data CRC Errors

Counts errors detected in the data portion of data frames sent to the device. Many data frames are used only for protocol control and do not contain a data portion, and thus cannot have Data CRC Errors. The Header CRC Errors check must be successful before the device attempts a Data CRC check. This attribute supplies an error count for the Bus Health Index attribute.

Data Expecting Reply Frames Rxed

Displays the number of data frames received by the device that require an immediate reply. This value includes proprietary frames that have been received and are expecting a reply.

Data Expecting Reply Frames Txed

Displays the number of data frames sent by the device that requires an immediate reply from the destination device.

This value includes proprietary frames that have been sent and are expecting a reply.

Data Not Expecting Reply Frames Rxed

Displays the number of data frames received by this item that do not require an immediate reply. This value includes proprietary frames that have been received and are not expecting a reply.

Data Not Expecting Reply Frames Txed

Displays the number of data frames sent by the device that do not require an immediate reply. This value includes proprietary frames that have been sent and received a reply.

Duplicate Device Identifiers

Lists any duplicate object identifiers found after an auto-discovery of MS/TP BACnet devices finishes. If any devices are listed, then the list of automatically discovered devices may be incomplete. The list contains the instance number of the Object Identifier and the network address (represented in hex notation) of each device with the same identifier instance number as another device on the same bus. MS/TP devices with duplicate device identifiers may be integrated without problem, but should be physically located and their object identifiers changed to make them unique network-wide.

Execution Time

Records the amount of time taken for the last periodic update of all referenced mapped BACnet objects. The value for this attribute can be used to tune the Periodic Update attribute. If the Execution Time is greater than the Periodic Update, attribute values of referenced BACnet objects are constantly being updated over the network. This attribute applies only to non-FEC series devices. See the Poll Delay attribute description for information on how these attributes interact.

Framing Errors

Counts the number of errors detected in the individual data bytes received by the device. A framing error occurs when the device receives a stop bit in the wrong state. This attribute supplies an error count for the Bus Health Index attribute. Framing errors are usually caused by electrical noise on the bus, message collisions, incorrect baud rate settings, bus wiring or termination errors, or devices that are not operating within the BACnet specified timing. Framing errors generally cause CRC errors since the frame has been corrupted.

Header CRC Errors

Counts the number of errors detected in the header portion of frames received by the device. Many frames are only used for protocol control and only contain a header portion. This attribute supplies an error count for the Bus Health Index attribute.

Internal Errors

Indicates the number of internal MS/TP driver operation errors resulting from an incorrect state, insufficient memory, errors from the serial port driver, incorrect internal state transitions, and other error states.

Logging Object Reference

Indicates the object (by way of the BACnet Object Identifier) that acquires, presents, and stores the Logging Record data (that is, snapshot) from the underlying system. When the object specified in the Logging Object Reference field issues the Get Monitor Data command, the Logging Record is acquired and updated.

Lost Token

Indicates the number of times the device detects a lost token. A lost token indicates that the bus encountered a serious network disruption. Serious disruption may occur when the bus first starts up or when wiring changes are made. This attribute supplies an error count for the Bus Health Index attribute.

Max Output Queue Used

Displays the largest number of outgoing frames the device has held in a queue for transmission. The largest possible value for this attribute depends on the capabilities of the engine. Generally, the maximum value is reached during device startup, but is not reached during normal operation.

Maximum Token Loop Time

Indicates the maximum time in milliseconds last seen at the device for the token to complete one circuit of the MS/TP field bus (go from the originating bus supervisor device through several other devices and return to the original bus supervisor device). The value is reset when the statistics are cleared. Maximum loop time is closely associated with the worst-case performance encountered since the last time the value was reset.

Overrun Errors

Displays the number of times the MS/TP port hardware loses received data because the device is too slow in reading the data. An overrun error occurs when the hardware receives a byte before it moves the prior byte to a buffer.

Packets Timed Out

Counts the number of data frames expected by the device that did not arrive within the time allowed.

Packets Too Long

Counts any attempts to transmit or receive a data frame that is longer than allowed by the device or by MS/TP.

PFM Frames Rxed

Displays the number of Poll For Master (PFM) frames received by the device. On a clean network, this should only count the first PFM frame received when the device (or another with a MAC address below that of the device) comes online. These frames are used to discover other devices on the network and should be seldom received.

PFM Frames Txed

Displays the number of PFM frames sent by the device. In normal operation on a clean network, only the bus supervisor (MAC address 0) and the highest numbered manager device on the network should be sending PFM frames. These frames are used to discover other devices on the network.

Polled Object Count

Indicates the number of mapped BACnet objects that are currently polled on a periodic basis. This attribute applies only to non-FEC series devices.

Port Status

Indicates the state of the port (Active or Inactive).

Predicted Token Loop

Indicates the theoretical time in milliseconds needed for the token to complete one circuit of the MS/TP field bus.

The object derives this value from the defined bus baud rate, number of devices on the bus, and an estimate of the type and amount of messages transmitted on the bus during this time. This object compares the value of this attribute with that of the Token Loop Time attribute to help calculate the value of the Bus Performance Index attribute.

Reply Postponed Frames Rxed

Counts the number of data frames sent to the device that require an immediate reply of which the destination device requests additional time to prepare the reply (hence, a postponement). This delay may occur if the reply involves a large amount of data or the device is overloaded.

Reply Postponed Frames Txed

Counts the number of data frames received at the device that requires an immediate reply of which the device requests additional time to prepare the reply (hence, a postponement). This delay may occur if the reply involves a large amount of data or the device is overloaded.

Reply to PFM Frames Rxed

Counts the number of Reply to PFM frames the device receives. On a clean network in normal operation, the device receives only one Reply to PFM frame when either the device comes online or the next higher numbered device comes online during normal operation. These frames announce the presence of this device on the network.

Reply to PFM Frames Txed

Counts the number of Reply to PFM frames the device transmits. On a clean network during normal operation, only one Reply to PFM frame needs to be sent when the device first comes online. These frames are used to announce the presence of other devices on the network.

Reply Too Slow Application Errors

Counts the number of data frames received at this device that requires an immediate reply where the device cannot assemble reply data within the time allowed and cannot internally detect the need for additional time. If these errors occur frequently, the device could be overloaded.

Reply Too Slow Datalink Errors

Counts the number of data packets sent by the device that requires an immediate reply from the destination device, but do not receive any reply within the time allowed. This number does not include Reply Postponed responses. The affected frames likely require a retry. Bus performance is reduced when this happens.

Reset Date

Specifies the date of the last Clear Statistics command (when the statistics for the device were last reset).

Reset Time

Specifies the time of the last Clear Statistics command (when the statistics for the device were last reset).

Retries

Displays the number of times the device tried to pass a token as the next node did not start using it within the time allowed by BACnet protocol.

Test Request Frames Rxed

Displays the number of Test Request Frames the device receives. Test Request Frames are a normal part of bus analysis, but should not be received during normal operation. A Test Response Frame should be sent in reply to each Test Request Frame received.

Test Request Frames Txed

Displays the number of Test Request Frames the device transmits. Test Request Frames are a normal part of bus analysis, but should not be sent during normal operation. A Test Response Frame should be received in response to each test Request Frame sent to an online device. Test Request Frames may also be sent to offline devices where no response is received.

Test Response Frames Rxed

Displays the number of Test Response Frames the device receives. Test Response Frames are a normal part of bus analysis, but should not be received during normal operation. A Test Response Frame should be received in response to each test Request Frame sent to an online device.

Test Response Frames Txed

Displays the number of Test Response Frames transmitted by this MS/TP port. Test Response Frames are a normal part of bus analysis, but should not be sent during normal operation. A Test Response Frame should be sent in response to each test Request Frame received.

Token Frames Rxed

Displays the number of Token Frames the device receives. In MS/TP, each manager device passes a logical token to the next device during normal operation. Only the manager device currently holding the token is allowed to initiate a message; thus, the number of Token Frames sent or received should be large. Normally the number of Token Frames received should be almost the same as the number of Token Frames transmitted.

Token Frames Txed

Displays the number of Token Frames the device transmits. In MS/TP, each manager device passes a logical token to the next device during normal operation. Only the manager device currently holding the token is allowed to initiate a message, thus the number of Token Frames sent or received should be large. Normally the number of Token Frames received should be almost the same as the number of Token Frames transmitted.

Token Loop Time

Indicates how much time passes between the periods when the device allows initiation of messages on the network. This time is a strong indicator of network performance and is associated strongly with the amount of traffic or errors on the network. Shorter time period indicate a more responsive network. Longer time period indicate an increasingly busy and slow network.

The object compares the value of this attribute with that of the Predicted Token Loop Time attribute to help calculate the value of the Bus Performance Index attribute.

Unexpect Frames Rxed

Displays the number of data frames of an illegal type that the device receives. During normal operation, only certain kinds of MS/TP data frames are allowed to be sent during each phase of operation. If the device receives some other kind of data frame (other than the allowed types for the current phase of operation), the device counts the data frame as an Unexpected Frame. The device may often detect Unexpected Frames when connecting running devices to a live MS/TP bus.

Weighted Bus Health Constant

Determines the responsiveness of the Bus Health Index. The default value is 0.50.

Weighted Bus Performance Constant

Determines the responsiveness of the Bus Performance Index. The default value is 0.50.

Table 4. SA Bus Integration Attributes - Hardware Tab

Attribute Name

Initial Value

Values/Options/Range

APDU Retries

3

Indicates the maximum number of times the device can retransmit a data frame. This attribute is fixed at 3.

APDU Segment Timeout

4000

Indicates the amount of time in milliseconds between retransmissions of a data frame segment requiring acknowledgment for which no acknowledgment has been received. This attribute is fixed at 4000 ms.

APDU Timeout

6000

Indicates the amount of time in milliseconds between retransmissions of a complete data frame requiring acknowledgment for which no acknowledgment has been received. This attribute is fixed at 6000 ms.

Baud Rate Selection

38400

Indicates the baud rate of the network engine SA Bus. This attribute is fixed at 38400 baud.

Configured Network Number

65000

Contains the network number of the SA bus used for BACnet message addressing. A value of 0 indicates a local network (the device is not intended as a router).

JCI MAC Address

0

Contains the unique hardware number that identifies the SA Bus within a network.

Max APDU Length

1476

Indicates the maximum number of bytes that may be contained in a single, indivisible application layer protocol data unit.

Max Manager

127

Specifies the highest possible address for devices on this network and is less than or equal to 127 (default). This attribute is present if the device is a bus supervisor device on an MS/TP network. Typically this address is kept at 127 to allow other devices on the bus to use any of the lower valid addresses.