MS/TP Field Bus Integration Attributes - Metasys - LIT-1201793 - Software Application - Site Management Portal - 12.0.50

Metasys Site Management Portal Help

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 MS/TP Field 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 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. MS/TP Field Bus Integration Attributes - Focus/Configuration Tab

Attribute Name

Notes

Description

Alarm State

 

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

APDU Length

W

Indicates the maximum number of octets that may be contained in a single indivisible application on this port. Supports up to 65535. This value must be greater than 50. This attribute appears only in the Snapshot Focus view of the object. The valid range for APDU length of controllers are 128-480.
Note: JCI field controllers do not support extended MS/TP frames.

APDU Retries

C,W

Indicates the maximum number of times the device can retransmit a data frame. If the device does not perform retries, it has a value of 0. If this value is greater than 0, a non-zero value appears in the APDU Segment Timeout attribute. Recommended settings: high or medium sensitivity: 3 (default); low sensitivity: 5.

Note: If you change the value of this attribute, you must reset the network engine for the new settings to take effect.

APDU Timeout

C,W

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 applies to smaller data messages where the entire message fits within a single frame on the MS/TP bus. Recommended settings: high sensitivity: 6000 ms; medium sensitivity: 12000 ms (default); low sensitivity: 30000 ms. The default number is 12000ms.

Note: If you change the value of this attribute, you must reset the network engine for the new settings to take effect.

APDU Segment Timeout

C,W

Indicates the amount of time in milliseconds between retransmissions of a data frame segment requiring acknowledgment for which no acknowledgment has been received. This value is not 0 if the device supports segmentation of transmitted data frames. Recommended settings: high sensitivity: 8000 ms; medium sensitivity: 11000 ms (default); low sensitivity: 29000 ms. The default number is 11000ms.

Note: If you change the value of this attribute, you must reset the network engine for the new settings to take effect.

Changes Pending

 

Indicates whether an object configuration change has not yet been activated. If this attribute is True, reset the engine or issue an Activate Changes command to the network engine.

Command

W

Describes an attribute that initiates specific functionality dependent upon the enumerated value written to it. In addition to basic defined commands described by BACnet PR18, there may also be vendor specific commands. Currently, only discarding of pending changes is supported. The default value for this attribute is Idle.

Count

 

Contains the number of FEC series and non-FEC series BACnet objects mapped on the field bus.

Device Discovery Range

C,W

Specifies the destinations for the messages sent during the device auto discovery process. This list is empty by default. When the list is empty, a global broadcast message is sent. Adding entries to the list limits the scope of the broadcast message to only the specified networks and device instance ranges. If multiple entries appear in the list, the messages are sent sequentially. This attribute appears only in the Snapshot Focus tab.

Discover All As General BACnet Device

C,W

Toggles the integration between pure BACnet mode and BACnet with proprietary messaging. When set to True, proprietary messaging is disabled. This may be useful for special cases where customers do not want Private Transfer messages on the BACnet trunk. Note that when this attribute is True, proprietary Objects, Attributes, and Services on Johnson Controls devices (such as Field Equipment Controllers (FECs), Advanced Application Field Equipment Controllers (FACs), and VAV Modular Assemblies (VMAs)) are not available. This attribute must be set before devices are added to the Integration. If you change the value, restart the supervisory device to make the change effective. You can restart immediately or after you have completed the mapping process. The default value is False.

Execution Priority

C,W

Indicates the order in which any given object within a group of objects is allowed to run or change data within a system. This attribute should not be changed for this object. This attribute appears only in the Snapshot Focus tab.

Internode Comm Timer

C,W

Controls the frequency of communication with MS/TP devices. Among other communications, this attribute defines the frequency of the heartbeat to monitored devices (monitored at a rate of two times the Internode Comm Timer). Recommended settings: high sensitivity: 30 seconds; medium sensitivity: 120 seconds (default); low sensitivity: 240 seconds.

Note: If you change the value of this attribute, you must reset the network engine for the new settings to take effect.

JCI Network Port APDU Retries

C,W

Indicates the maximum number of times the device can retransmit a data frame. If the device does not perform retries, it has a value of 0. If this value is greater than 0, a non-zero value appears in the JCI Network Port APDU Segment Timeout attribute. Recommended settings: high or medium sensitivity: 3 (default); low sensitivity: 5.

Note: If you change the value of this attribute, you must reset the network engine for the new settings to take effect.

JCI Network Port APDU Timeout

C,W

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 applies to smaller data messages where the entire message fits within a single frame on the MS/TP bus. Recommended settings: high sensitivity: 6000 ms; medium sensitivity: 12000 ms (default); low sensitivity: 30000 ms. The default number is 12000ms.

Note: If you change the value of this attribute, you must reset the network engine for the new settings to take effect.

JCI Network Port APDU Segment Timeout

C,W

Indicates the amount of time in milliseconds between retransmissions of a data frame segment requiring acknowledgment for which no acknowledgment has been received. This value is not 0 if the device supports segmentation of transmitted data frames. Recommended settings: high sensitivity: 8000 ms; medium sensitivity: 11000 ms (default); low sensitivity: 29000 ms. The default number is 11000ms.

Note: If you change the value of this attribute, you must reset the network engine for the new settings to take effect.

Max APDU Length

C,W

Indicates the maximum number of bytes that may be contained in a single, indivisible application layer protocol data unit. This value should not be changed during normal installation or operation. The default value is 1476 bytes.

If you write the value of this attribute, you must issue a Reset Device command to the network engine or the new settings to take effect.

Max Info Frames

C,W

Specifies the maximum number of information frames the node may send before it passes the token. This attribute is present if the device is a node on an MS/TP network. If Max Info Frames is not writable or otherwise user configurable, its value is one. If you change this value, you must activate it with the Activate Changes > Update Changes Pending Attributes Except Network Number command to the Engine. The pending value is updated immediately but it is not applied until you activate the change.

Note: If the device is an MS/TP manager node, both the Max Info Frames and Max Manager attributes are required.

Max Manager

C,W

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.
Note: We recommend that you use a value higher than your highest controller MS/TP MAC address to avoid the out of range error.

Out of Service

 

Indicates whether the field bus is out of service. This value is always false.

Page Size

C,W

Determines how many points are discovered per page. The default value is 1,000.

Periodic Update

C,W

Specifies how frequently integrated BACnet objects that do not support COV subscription update their attribute values. Every period, the MS/TP Field Bus Integration object prompts each integrated BACnet object that needs to update its attribute values. This attribute applies only to non-FEC series devices. See the Poll Delay attribute description for information on how these attributes interact. The default value is 20 seconds.

Poll Delay

C,W

Specifies the time in milliseconds between BACnet object polls for attribute values. The polls start at the time specified in the Periodic Update attribute. As the poll delay increases, the overall time in the Execution Time attribute increases.

It is useful to specify a Poll Delay on sites where the rate of reading the remote objects causes too high of a burden on the Metasys network or third-party device. The initial value of the Poll Delay attribute is blank (zero).

Preserve Discovered Devices

C,W

Controls the behavior when field device discovery is started. This attribute exists for historical reasons and is ignored by the MS/TP Field Bus Integration object for FEC series or non-FEC series devices. The value of the attribute is shown in the snapshot view. If an auto discovery has been completed since the last device restart, a complete new auto discovery is performed for all FEC Series or non-FEC Series devices for each subsequent auto discovery in which Restart is selected. The default is True.

Reliability

 

Indicates the current reliability of the integration. The normal state is Reliable.

Requested Vendor ID

C,N

Used as a filter when discovering new devices to limit the device list to whatever is specified as the Vendor ID value. The default value of this attribute is Null (stored as zero), which allows all vendors to be discovered and displayed. Note that this filter applies only to non-Johnson Controls devices. Johnson Controls devices are always included in the discovered device list.

The current list of Vendor IDs can be viewed at http://www.bacnet.org/VendorID/BACnet%20Vendor%20IDs.htm.
Note: If you do not want to display devices already discovered or mapped, then set Preserve Discovered Devices to False.

Status Flags

 

Indicates the general status of the object in BACnet terms and contains four independent states.

The four selections are:

In Alarm—False if the Event State attribute value is Normal; otherwise, the In Alarm flag is True. (Set only by BACnet Intrinsic Alarming.)

Fault—True (1) if the Reliability attribute is not reliable; otherwise, the Fault flag is False.

Overridden—Overridden flag is True if the Present Value is overridden from the hardware source level.

Out of Service—Out of Service flag is True if the Out of Service attribute value is True; otherwise, the Out of Service flag is False.

Synchronize Time

C,W

Broadcasts time synchronization to all devices on the field bus when the field device comes online or when the time changes by a significant amount. When changed from false to true, a time synchronization is sent immediately to all devices on the field bus. The default is True.

Synchronize Time Zone

C,W

Enables and disables time zone synchronization messages to devices (such as FACs) on a trunk that support real-time clock capabilities. When this attribute is set to True (default), time zone synchronization messages are broadcast to devices on the field bus. The broadcast occurs either when individual devices come online or to all devices when any of the time zone related attributes change (Default Time Zone, UTC Offset, Standard Time Offset, Daylight Savings Time Offset, Standard Time Start, and Daylight Savings Time Start). When changed from false to true, time zone synchronization is automatically sent to all devices on the field bus.

Table 2. MS/TP Field 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, it indicates that 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, it indicates that 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 FC 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.

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.

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.

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.

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 at the device that requires an immediate reply where the destination device requests additional time to prepare the reply. This may happen normally if the reply involves a large amount of data. It may also indicate that a device on the network is overloaded.

Reply Postponed Frames Txed

Counts the number of data frames received at the device that requires an immediate reply where this device requests additional time to prepare the reply. This may happen normally if the reply involves a large amount of data. It may also indicate that this 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. These errors generally indicate an overloaded device if they occur frequently.

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 and bus performance is reduced when this happens.

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

Reset Time

Contains 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.

Unexpected 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 3. MS/TP Field Bus Integration Attributes - Hardware Tab

Attribute Name

Flags

Initial Value

Values/Options/Range

Baud Rate Selection

C,W

38400

Indicates the baud rate of the network engine FC bus.
Baud Rate Description
Auto

Use baud rate of running network. This value is the recommended setting for everything on the FC bus except the bus supervisor port. See Active Baud Rate.

1200

Use 1200 baud only. This value is not recommended and may not be allowed on some devices.
9600 Use 9600 baud only. This value is the lowest standard MS/TP baud rate.
19200 Use 19200 baud only. This value is not recommended.
38400 Use 38400 baud only. This value is the recommended baud rate for bus supervisor ports.
76800 Use 76800 baud only.

Configured Network Number

C,W

2000

Contains the network number of the MS/TP bus used for BACnet message addressing. A value of 0 indicates a local network (the device is not intended as a router). Do not change this number after you start device mapping or discovery because it may invalidate the devices that have been found.

Trunk Number

 

1

Displays the trunk number where the field bus is located.