SMC Networks FieldServer FS-8700-16 BACnet PTP Driver Manual

Driver Revision: 2.01

Document Revision: 1.B

FieldServer

FS-8700-16 BACnet PTP – Serial

Driver Manual

(Supplement to the FieldServer Instruction Manual)

APPLICABILITY & EFFECTIVITY

Effective for all systems manufactured after May 2019.

BACnet PTP Serial Driver Manual

Contact Information

Technical Support

Please call us for any technical support needs related to the FieldServer product.

Sierra Monitor Corporation
1991 Tarob Court
Milpitas, CA 95035

Website: www.sierramonitor.com

U.S. Support Information:

[phone]
[phone]

Email: [e-mail]

EMEA Support Information:

[phone]

Email: [e-mail]

BACnet PTP Serial Driver Manual

Table of Contents

TABLE OF CONTENTS

1 BACnet PTP Description ..................................................................................................................... 5

2 Driver Scope of Supply ....................................................................................................................... 5

2.1 Supplied by Sierra Monitor Corporation ......................................................................................... 5

2.2 Provided by supplier of 3rd party equipment ................................................................................... 5

3 Hardware Connections ........................................................................................................................ 6

4 Data Array Parameters ........................................................................................................................ 7

5 Configuring the FieldServer as a BACnet Client .............................................................................. 8

5.1 Setting the FieldServer Node_ID .................................................................................................... 8

5.2 Client Side Connection Parameters ............................................................................................... 8

5.3 Client Side Node Parameters ......................................................................................................... 9

5.4 Map Descriptor Parameters ............................................................................................................ 9

5.4.1 Client Side Connection Parameters ...................................................................................... 10

5.4.2 Timing Parameters ................................................................................................................ 10

5.4.3 Map Descriptor Example ....................................................................................................... 11

6 Configuring the FieldServer as a BACnet Server ........................................................................... 12

6.1 Driver Specific FieldServer Parameters ....................................................................................... 12

6.2 Server Side Connection Parameters ............................................................................................ 12

6.3 Server Side Node Parameters ...................................................................................................... 13

6.4 Server Side Map Descriptor Parameters ...................................................................................... 13

6.4.1 FieldServer Specific Map Descriptor Parameters ................................................................. 13

6.4.2 Driver Specific Map Descriptor Parameters .......................................................................... 14

6.4.3 Map Descriptor Example ....................................................................................................... 15

Appendix A. Useful Features ................................................................................................................... 16

Appendix A.1. BACnet Object Names ..................................................................................................... 16

Appendix A.2. Network Number .............................................................................................................. 16

Appendix A.3. Accessing Data from BACnet Properties Comprising Arrays of Values .......................... 17

Appendix A.4. FieldServer Implementation of BACnet Priority Arrays .................................................... 17

Appendix A.4.1. Accessing Priority Array Information ......................................................................... 17

Appendix A.5. BACnet State Text Preload .............................................................................................. 18

Appendix A.5.1. Method 1 – Using an Offset/User Table .................................................................... 18

Appendix A.5.2. Method 2 – Using a Single Data Array ...................................................................... 18

Appendix A.5.3. Using Intrinsic Reporting for a Multistate Value ........................................................ 19

Appendix A.6. COV and Intrinsic Reporting ............................................................................................ 20

Appendix A.6.1. Notes on COV Configuration ..................................................................................... 20

Appendix A.6.2. Notes on Intrinsic Reporting Configuration: .............................................................. 20

Appendix A.7. Map Descriptor Examples ................................................................................................ 21

Appendix A.7.1. COV ........................................................................................................................... 21

Appendix A.7.2. Intrinsic Reporting ..................................................................................................... 21

Appendix A.7.3. Enable or Disable COV ............................................................................................. 21

Appendix A.8. Reliability_Option ............................................................................................................. 22

Appendix A.9. Specifying ReadPropertyMultiple and WritePropertyMultiple Transactions Using Linked

Map Descriptors ...................................................................................................................................... 23

Appendix B. Troubleshooting .................................................................................................................. 25

Appendix B.1. Debugging a BACnet Connection .................................................................................... 25

Appendix B.2. BACnet Error Response Decoding .................................................................................. 25

Appendix B.2.1. BACnet Error CLASS ................................................................................................ 25

Appendix B.2.2. BACnet Error CODES for Error Class OBJECT ....................................................... 26

BACnet PTP Serial Driver Manual

Table of Contents

Appendix C. Vendor Information ............................................................................................................. 27

Appendix C.1. McQuay............................................................................................................................ 27

Appendix C.2. Trane ................................................................................................................................ 27

Appendix C.3. Liebert .............................................................................................................................. 27

Appendix C.4. Automated Logic Corporation .......................................................................................... 27

Appendix C.5. Honeywell EBI ................................................................................................................. 27

Appendix D. Reference ............................................................................................................................. 28

Appendix D.1. Object_Type Legal Values – Abbreviation Descriptions ................................................. 28

Appendix D.2. Property Legal Values ..................................................................................................... 28

Appendix D.3. BACnet Vendor ID ........................................................................................................... 30

Appendix D.4. Units ................................................................................................................................. 30

Appendix D.5. BACnet Specific Statistics ............................................................................................... 34

BACnet PTP Serial Driver Manual

Page 5 of 34

1 BACNET PTP DESCRIPTION

The BACnet PTP driver allows the FieldServer to transfer data to and from devices using the BACnet
protocol over a serial RS-232 physical layer. The FieldServer can emulate either a Server or Client.

All information in a BACnet system is represented in terms of objects. The Object_Identifier is a 32-bit
code that identifies the type of Object (also identified by the Object_Type Property) and its "Instance"
number, which together uniquely identify the Object within its BACnet device. Theoretically, a BACnet
device could have over four million Objects of a particular type. The Object_Name is a text string, which
has a unique capability. BACnet devices may broadcast queries for devices that contain Objects with a
specific Object_Name. This can greatly simplify project setup.

BACnet requires one Device Object to be present in every BACnet device. The Device Object makes
information about the device and its capabilities available to other devices on the networks. Before one
BACnet device starts control-related communications with another, it needs to obtain some of the
information presented by the other device's Device Object. Unlike other Objects, the Device Object's
Instance number must be unique across the entire BACnet internetwork because it is used to uniquely
identify the BACnet devices. It may be used to conveniently identify the BACnet device from other
devices during installation.

Standard object types are used to hold real time data and other information. Each Object Type is
referenced by a number, for example 0 represents an Analog Input.

Each Object consists of a number of prescribed properties, the main property being the Present_Value.
Objects are monitored and controlled through their properties. The Analog Input Object is representative
of the Objects involved directly with control elements and many of its Properties reflect this.

The information that follows describes how to expand upon the factory defaults provided in the
configuration files included with the FieldServer.

2 DRIVER SCOPE OF SUPPLY

2.1 Supplied by Sierra Monitor Corporation

Part #

Description

FS-8917-03

Connector adapter – DB9M to DCE, RTS/CTS, DSR/DTR

2.2 Provided by supplier of 3rd party equipment

Part #

Description

BACnet Controller

BACnet PTP Serial Driver Manual

Page 6 of 34

3 HARDWARE CONNECTIONS

It is possible to connect a BACnet device to any of the eight RS-2321 ports. These ports just need to be
configured for BACnet in the configuration file.

Configure the device according to manufacturer’s instructions:

FUNCTION FROM TO COLOUR

RX RJ45-01 DB9M-02 GREY
CTS RJ45-02 DB9M08 BROWN
DSR RJ45-03 DB9M-06 YELLOW
GND RJ45-04 DB9M-05 GREEN
GND RJ45-05 RED

TX RJ45-08 DB9M-03 BLUE

RTS RJ45-07 DB9M-07 ORANGE

DTR RJ45-06 DB9M-04 BLACK

8917-03 WIRE LIST

8917-03

8917-03

FieldServer

FieldServer Part #

8917-16

Brown

Orange/White

8
TX

1

RX

4

COM

GND Tx Rx

Blue/White

1

Not all ports shown are necessarily supported by the hardware. Consult the appropriate Instruction manual for details of the ports

available on specific hardware.

BACnet PTP Serial Driver Manual

Page 7 of 34

4 DATA ARRAY PARAMETERS

Data Arrays are “protocol neutral” data buffers for storage of data to be passed between protocols. It is
necessary to declare the data format of each of the Data Arrays to facilitate correct storage of the relevant
data.

Section Title

Data_Arrays

Column Title

Function

Legal Values

Data_Array_Name

Provide name for Data Array.

Up to 15 alphanumeric
characters

Data_Array_Format

Provide data format. Each Data Array can only
take on one format.

Float, Bit, Byte, Uint16, Uint32,
Sint16, Sint32

Data_Array_Length

Number of Data Objects. Must be larger than
the data storage area required by the Map
Descriptors for the data being placed in this
array.

1-10000

Example

// Data Arrays

Data_Arrays

Data_Array_Name

, Data_Array_Format

, Data_Array_Length

DA_AI_01

, Float

, 200

DA_AO_01

, Float

, 200

DA_DI_01

, Bit

, 200

DA_DO_01

, Bit

, 200

BACnet PTP Serial Driver Manual

Page 8 of 34

5 CONFIGURING THE FIELDSERVER AS A BACNET CLIENT

For detailed information on FieldServer configuration, refer to the FieldServer Instruction Manual. The
information that follows describes how to expand upon the factory defaults provided in the configuration
files included with the FieldServer (see “.csv” sample files provided with the FieldServer).

This section documents and describes the parameters necessary for configuring the FieldServer to
communicate with a BACnet PTP Server.

The configuration file tells the FieldServer about its interfaces, and the routing of data required. In order to
enable the FieldServer for BACnet communications, the driver independent FieldServer buffers need to

be declared in the “Data Arrays” section, the destination device addresses need to be declared in the

“Client Side Nodes” section, and the data required from the Servers needs to be mapped in the “Client

Side Map Descriptors” section. Details on how to do this can be found below.

NOTE: In the following tables, * indicates an optional parameter and bold legal values are default.

5.1 Setting the FieldServer Node_ID

Section Title

FieldServer

Column Title

Function

Legal Values

System_Node_ID

Configure Node_ID of FieldServer.

1-255

Example

// FieldServer

FieldServer

Title

, System_Node_ID

BACnet_PTP

, 11

5.2 Client Side Connection Parameters

Section Title

Connections

Column Title

Function

Legal Values

Port

Port Name.

P1-P22

Baud*

Specify baud rate.

110; 300; 600; 1200; 2400; 4800; 9600; 19200; 38400;
57600; 115000

Parity*

Specify parity.

Odd, Even, None

Data_Bits*

Specify data bits.

7, 8

Stop_Bits*

Specify stop bits.

1,2

Protocol

Specify Protocol Used.

BACnet_PTP

Example

// Client Side Connections

Connections

Port

, Baud

, Parity

, Data_Bits

, Stop_Bits

, Protocol

P2

, 9600

, Even

, 7

, 1

, BACnet_PTP

2

Not all ports shown are necessarily supported by the hardware. Consult the appropriate Instruction manual for details of the ports

available on specific hardware.

BACnet PTP Serial Driver Manual

Page 9 of 34

5.3 Client Side Node Parameters

Section Title

Nodes

Column Title

Function

Legal Values

Node_Name

Provide name for Node.

Up to 32 alphanumeric characters

Node_ID

Specify the BACnet Device object instance.

1 - 16777215

Protocol

Specify protocol used.

BACnet_PTP

Port

Specify port.

P1-P2

Retries*

Number of timeouts before the Node goes offline.

0,1,2,3

Example

// Client Side Nodes

Nodes

Node_Name

, Node_ID

, Protocol

, Port

, Retries

DEV_1

, 1

, BACnet_PTP

, P1

, 2

5.4 Map Descriptor Parameters

Column Title

Function

Legal Values

Map_Descriptor_Name

Name of this Map Descriptor. This is used
for Object_Name Property. Refer to

Appendix A.1.

Up to 32 alphanumeric
characters

Data_Array_Name

Name of Data Array where data is to be
stored in the FieldServer.

One of the Data Array names
from Section 4

Data_Array_Offset

Starting location in Data Array.

0 to (Data_Array_Length-1) as
specified in Section 4

Function

Function of Client Map Descriptor.

Rdbc, Wrbc, Wrbx, Arcs

BACnet PTP Serial Driver Manual

Page 10 of 34

5.4.1 Client Side Connection Parameters

Column Title

Function

Legal Values

Node_Name

Name of Node to fetch data from.

One of the Node_Names
specified in Section 5.3

Object_Type
(Alias = Data_Type)

Type of object. Refer to Appendix D.1 for
more information.

AI, AO, AV, BI, BO, BV, MI,
MO, MV, NC

Object_Instance
(Alias = Address)

Instance of the object on the device.

0, 1, 2, 3, …4194303
Property

The BACnet property to be read.

Refer to Appendix D.2

Data_Array_Low_Scale*

Scaling zero in Data Array.

-32767 to 32767, 0

Data_Array_High_Scale*

Scaling max in Data Array.

-32767 to 32767, 100

Node_Low_Scale*

Scaling zero in Connected Node.

-32767 to 32767, 0

Node_High_Scale*

Scaling max in Connected Node.

-32767 to 32767, 100

Length*

Used to create an array of sequential
Object_Instances on an Object_Type.

1 to max point count of the
FieldServer, 1

Array_Index*

When referencing Multistate properties,
allows the user to specify the index of the
property to be read. If 1 is specified, the
first one will be read, if 2 is specified, the
second will be read, etc. If 0 is specified,
the driver will return the total number
(count) of array items linked to the
property. If the parameter is not specified,
a list of all items will be returned. Refer to

Appendix A.3.

0 to max number of array items
in the BACnet Property, -

Write_Priority*

Allows the driver to specify the write
priority used to write an output.

1..16, 16

Linked_Map_Descriptors*

This parameter allows the linking of Map
Descriptors to an active read or write Map
Descriptor in order to construct a
ReadPropertyMultiple or
WritePropertyMultiple transaction. Refer
to Appendix A.9.

The name of a previously
defined active Map Descriptor,

-

Length*

When the optional Length parameter is
set to a value N, the Map Descriptor will
include N consecutive instances of the
specified Object_Type. For example, if a
Map Descriptor specifies Object_Type,
Address 4 and Length 3, this means that
the AO instances 4, 5 and 6 will be
included in the read or write transaction.
The corresponding Data Array values are
in consecutive positions in the Data Array,
starting at the specified
Data_Array_Offset.

Any positive integer that falls
between the range of the
Data_Array_Offset and the
Data_Array_Length as
specified in Section 4, -
Refer also to Appendix A.9

5.4.2 Timing Parameters

Column Title

Function

Legal Values

Scan_Interval*

Rate at which data is polled

0-32000, 2s

BACnet PTP Serial Driver Manual

Page 11 of 34

5.4.3 Map Descriptor Example

// Client Side Map Descriptors

Map_Descriptors

Map_Descriptor_Name

, Data_Array_Name

, Data_Array_Offset

, Function

, Node_Name

, Data_Type

, Object_Instance

, Property

, Scan_Interval

CMD_AI_01

, DA_AI_01

, 0

, Rdbc

, DEV_1

, AI

, 1

, Present_Value

, 20.000s

CMD_AI_02

, DA_AI_01

, 1

, Rdbc

, DEV_1

, AI

, 2

, Present_Value

, 20.000s

CMD_AI_03

, DA_AI_01

, 2

, Rdbc

, DEV_1

, AI

, 3

, Present_Value

, 20.000s

CMD_AO_01

, DA_AO_01

, 0

, Rdbc

, DEV_1

, AO

, 1

, Present_Value

, 30.000s

CMD_AO_02

, DA_AO_01

, 1

, Rdbc

, DEV_1

, AO

, 2

, Present_Value

, 30.000s

CMD_AO_03

, DA_AO_01

, 2

, Rdbc

, DEV_1

, AO

, 3

, Present_Value

, 30.000s

Map_Descriptors

Map_Descriptor_Name

, Data_Array_Name

, Data_Array_Offset

, Function

, Node_Name

, Data_Type

, Object_Instance

, Property

, Scan_Interval

CMD_DI_01

, DA_DI_01

, 0

, Rdbc

, DEV_1

, BI

, 1

, Present_Value

, 15.000s

CMD_DI_02

, DA_DI_01

, 1

, Rdbc

, DEV_1

, BI

, 2

, Present_Value

, 15.000s

CMD_DI_03

, DA_DI_01

, 2

, Rdbc

, DEV_1

, BI

, 3

, Present_Value

, 15.000s

CMD_DO_01

, DA_DO_01

, 0

, Rdbc

, DEV_1

, BO

, 1

, Present_Value

, 30.000s

CMD_DO_02

, DA_DO_01

, 1

, Rdbc

, DEV_1

, BO

, 2

, Present_Value

, 30.000s

CMD_DO_03

, DA_DO_01

, 2

, Rdbc

, DEV_1

, BO

, 3

, Present_Value

, 30.000s

BACnet PTP Serial Driver Manual

Page 12 of 34

6 CONFIGURING THE FIELDSERVER AS A BACNET SERVER

For detailed information on FieldServer configuration, refer to the FieldServer Configuration Manual. The
information that follows describes how to expand upon the factory defaults provided in the configuration
files included with the FieldServer (see “.csv” sample files provided with the FieldServer).

This section documents and describes the parameters necessary for configuring the FieldServer to
communicate with a BACnet PTP Client.

The configuration file tells the FieldServer about its interfaces, and the routing of data required. In order to
enable the FieldServer for BACnet communications, the driver independent FieldServer buffers need to

be declared in the “Data Arrays” section, the FieldServer virtual node(s) needs to be declared in the

“Server Side Nodes” section, and the data to be provided to the clients needs to be mapped in the
“Server Side Map Descriptors” section. Details on how to do this can be found below.

NOTE: In the tables below, * indicates an optional parameter, with the bold legal value as default.

6.1 Driver Specific FieldServer Parameters

Section Title

Bridge

Column Title

Function

Legal Values

Title

FieldServer name.

Text

Network_Number*

Specify a unique network number if there are multiple virtual
Server nodes. Refer to Appendix A.2.

1-65535

5

Example

// FieldServer Driver specific parameters

Bridge

Title

BACnet Server

6.2 Server Side Connection Parameters

Section Title

Connections

Column Title

Function

Legal Values

Port

Specify which port the device is connected to the
FieldServer.

P1-P2

Baud*

Specify baud rate.

110; 300; 600; 1200; 2400;
4800; 9600; 19200; 38400;
57600; 115000

Parity*

Specify parity.

None, Odd, Even

Data_Bits*

Specify data bits.

7, 8

Stop_Bits*

Specify stop bits.

1, 2

Protocol

Specify protocol used.

BACnet_PTP

Reliability_Option*

The Reliability_Option parameter selects the rules
by which the BACnet Server determines the
Reliability property of a BACnet object whose
present value is read from a Remote Server Node.
Refer to Appendix A.8.

Track_Object_Status,
Track_Node_Status,
Always_Reliable

BACnet PTP Serial Driver Manual

Page 13 of 34

Example

// Server Side Connections
Connections

Port

, Baud

, Parity

, Data_Bits

, Stop_Bits

, Protocol

P1

, 9600

, Even

, 7

, 1

, BACnet_PTP

6.3 Server Side Node Parameters

Section Title

Nodes

Column Title

Function

Legal Values

Node_Name3

Provide name for node.

Up to 32 alphanumeric characters

Node_ID

BACnet station address of physical Server node.

1 - 16777215

Protocol

Specify protocol used.

BACnet_PTP

Node_Option

Enable or disable COV for this node.

COV_Enable, COV_Disable

Example

// Server Side Nodes

Nodes

Node_Name

, Node_ID

, Protocol 4

Virtual_DEV_11

, 11

, BACnet_PTP

6.4 Server Side Map Descriptor Parameters

6.4.1 FieldServer Specific Map Descriptor Parameters

Column Title

Function

Legal Values

Map_Descriptor_Name

Name of this Map Descriptor. This is used
for Object_Name Property. Refer to

Appendix A.1.

Up to 32 alphanumeric
characters

Data_Array_Name

Name of Data Array where data is to be
stored in the FieldServer.

One of the Data Array names
from Section 4

Data_Array_Offset

Starting location in Data Array.

0 to (“Data_Array_Length” -1) as
specified in Section 4

Function

Function of Server Map Descriptor.

Passive

3

When using the Trane Tracer Summit Workstation System, this name will appear as the object name.

4

Note that Port is not declared in the Server Side Nodes.

BACnet PTP Serial Driver Manual

Page 14 of 34

6.4.2 Driver Specific Map Descriptor Parameters

Column Title

Function

Legal Values

Node_Name

Name of Node to fetch data from.

One of the Node Names specified
in “Server Side Node Descriptors”

Object_Type
(Alias = Data_Type)

Data type in Controller.

AI, AO, AV, BI, BO, BV, MI, MO,
MV, NC. Refer to Appendix D.1.

Object_Instance
(Alias = Address)

Instance of the Object on the Device.

0, 1, 2, 3, …4194303
Units*

The object units.

Refer to Appendix D.3, m2

Data_Array_Low_Scale*

Scaling zero in Data Array.

-32767 to 32767, 0

Data_Array_High_Scale*

Scaling max in Data Array.

-32767 to 32767, 100

Node_Low_Scale*

Scaling zero in Connected Node.

-32767 to 32767, 0

Node_High_Scale*

Scaling max in Connected Node.

-32767 to 32767, 100

Active_Text5*

Specify the Active Text property of the
Object.

Any text string of length up to 40
characters, Active

Inactive_Text5*

Specify the Inactive Text property of
the Object.

Any text string of length up to 40
characters, Inactive

Relinquish_Default5

Specify the value to be returned as
Present_Value on startup or when
control is relinquished. Must be
specified for outputs. Refer to

Appendix D.2.

Any Float value
Length*

Used to create an array of sequential
Object_Instances on an Object_Type.

1 to max point count of the
FieldServer, 1

Notification_Class*

Specify the Mapdescriptor_Name of
the Notification_Class Object that
manages Intrinsic Reporting for this
Map Descriptor. Refer to Appendix

A.6.

One of the configured
Mapdescriptor_Names of type NC
(Notification Class). Objects are not
available to any NC if left out.

Ack_Required*

For a Notification_Class Object,
specify whether EventNotifications
require a user Acknowledgement.
Refer to Appendix A.6.

Yes, No

COV_Increment*

For a Server Map Descriptor of type
AO or AI, initialize the
COV_Increment property. Refer to

Appendix A.6.

Any Float value, 0
Input_alarm_State*

For binary points the user can specify
which of the states (0 or 1) to regard
as an alarm state.

0, 1

Description*

Specify the object’s description
property. E.G. Room Temp – Refer to

Appendix A.7.

Any text string of length up to 40
characters, if not configured,
defaults to Object_Name.

5

See the BACnet DFS to determine if a particular object supports this property.

BACnet PTP Serial Driver Manual

Page 15 of 34

6.4.3 Map Descriptor Example

// Server Side Map Descriptors

Map_Descriptors

Map_Descriptor_Name

, Data_Array_Name

, Data_Array_Offset

, Function

, Node_Name

, Object_Type

, Object_Instance

, Units

SMD_AI_01

, DA_AI_01

, 0

, Passive

, Virtual_DEV_11

, AI

, 1

, Degrees-Fahrenheit

SMD_AI_02

, DA_AI_01

, 1

, Passive

, Virtual_DEV_11

, AI

, 2

, Degrees-Fahrenheit

SMD_AI_03

, DA_AI_01

, 2

, Passive

, Virtual_DEV_11

, AI

, 3

, Degrees-Fahrenheit

SMD_AO_01

, DA_AO_01

, 0

, Passive

, Virtual_DEV_11

, AO

, 1

, percent-relative-humidity

SMD_AO_02

, DA_AO_01

, 1

, Passive

, Virtual_DEV_11

, AO

, 2

, percent-relative-humidity

SMD_AO_03

, DA_AO_01

, 2

, Passive

, Virtual_DEV_11

, AO

, 3

, percent-relative-humidity

Map_Descriptors

Map_Descriptor_Name

, Data_Array_Name

, Data_Array_Offset

, Function

, Node_Name

, Object_Type

, Object_Instance

SMD_DI_01

, DA_DI_01

, 0

, Passive

, Virtual_DEV_11

, BI

, 1 SMD_DI_02

, DA_DI_01

, 1

, Passive

, Virtual_DEV_11

, BI

, 2 SMD_DI_03

, DA_DI_01

, 2

, Passive

, Virtual_DEV_11

, BI

, 3

SMD_DO_01

, DA_DO_01

, 0

, Passive

, Virtual_DEV_11

, BO

, 1

SMD_DO_02

, DA_DO_01

, 1

, Passive

, Virtual_DEV_11

, BO

, 2 SMD_DO_03

, DA_DO_01

, 2

, Passive

, Virtual_DEV_11

, BO

, 3

BACnet PTP Serial Driver Manual

Page 16 of 34

Appendix A. Useful Features

Appendix A.1. BACnet Object Names

When an external BACnet Client builds a list of Object Names, the BACnet Server Map Descriptor names
determine the BACnet Object Name. If the Map Descriptor length is greater than 1, the Object Name will
be suffixed with the index into the Map Descriptor. For example, if the Map Descriptor name is
SMD_AI_01 and the length 3, then the Object Names will be SMD_AI_01[0], SMD_AI_01[1] and
SMD_AI_01[2].

Appendix A.2. Network Number

If multiple BACnet Nodes are specified on the Server side, the FieldServer automatically defaults to
virtual operation. In effect, the FieldServer simulates a software router. BACnet identifies this FieldServer
using a combination of its network number and IP/MAC address. The default Network number of a
FieldServer is 5. If there is more than one FieldServer on a BACnet intranet with multiple nodes, the
default network number of the additional FieldServers will need to be changed and a unique number
allocated to each.

A unique network number will need to be assigned if both of the following conditions are true:

• The FieldServer has multiple BACnet Server nodes.

• There is more than one FieldServer on a network which includes multiple BACnet nodes.

To override the FieldServer’s default network number 5 include the following in the configuration file:

Section Title

Bridge

Column Title

Function

Legal Values

Title

FieldServer name.

Text

Network_Number*

Specify a unique network number if there are multiple virtual
Server nodes.

1-65534, 5

Example

// FieldServer Driver specific parameters

Bridge

Title

, Network_Number

BACnet Server

, 6

NOTE: While it is theoretically possible to have up to 65535 virtual nodes, it is recommended that

a maximum of 32 is configured. If an application requires the configuration of more than
32 virtual nodes, consult Sierra Monitor technical support.

BACnet PTP Serial Driver Manual

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Appendix A.3. Accessing Data from BACnet Properties Comprising Arrays of Values

Some BACnet Object properties (e.g. Priority_Array) are arrays of values (the Priority_Array property is
an array of 16 values). In order to read a specific array entry, the Array_Index must be specified in the
Map Descriptor. Array_Index is a Client Side Map Descriptor function

The following example shows a configuration that will read the Priority_Array value at Array_Index 7,
belonging to Analog Output 1.

Map_Descriptors

Map_Descriptor_Name

, Data_Array_Name

, Data_Array_Offset

, Function

, Node_Name

CMD_AI_01

, DA_AI_01

, 0

, Rdbc

, DEV_01

, Data_Type

, Object_ID

, Property

, Array_Index

, AO

, 1

, Priority_Array

, 7

Details of the relevant BACnet properties and their associated arrays can be found in the BACnet
Protocol Spec.

Appendix A.4. FieldServer Implementation of BACnet Priority Arrays

When BACnet Output objects are written to the Server side of the FieldServer, an associated write priority
is given to each write value. When the FieldServer receives the write value, it stores it to the Map
Descriptor Priority Array Table at the specified priority. The Priority Array Table is then scanned and the
value with the highest priority is stored to the Data Array location specified by the Map Descriptor.

When a Write “Relinquished” command is received, the value is removed from the Priority Array Table

and the next highest value from the Priority Array Table is stored to the Data Array.

If all values have been “Relinquished” from the Priority Array Table, then the Map Descriptors “Relinquish

Default” value will be stored to the Data Array.

Appendix A.4.1. Accessing Priority Array Information

The Priority Array table and its “In_Use” (or Not Relinquished) state are stored internally to every Map
Descriptor and cannot be accessed directly. The information can be accessed indirectly by specifying the
following Data Arrays which will maintain an exact copy of the Priority Array Table for the Map Descriptor.

Section Title

Map_Descriptors

Column Title

Function

Legal Values

DA_Pri_Array

Name of the Data Array that contains the Priority Array Table.
Location 0 is the Relinquish Default value and locations 1 to
16 the different entries of the Priority Array Table.

Up to 16
alphanumeric
characters

DA_Pri_Array_Offset*

Starting location in Data Array.

1-65535, 0

DA_Pri_In_Use

Name of Data Array that indicates if a particular Priority Value
is in use. Location 0 indicates whether the Relinquish Default
has been set and locations 1 to 16 indicate whether the index
is in use (1), or Relinquished (0).

Up to 16
alphanumeric
characters

DA_Pri_In_Use_Offset*

Starting location in Data Array.

1-65535, 0

Example

// Analog Output Map_Descriptor for testing Priority Arrays

Map_Descriptors

Map_Descriptor_Name

, Data_Type

, Object_ID

, Function

, Data_Array_Name

, Data_Array_Index

, Node_Name

, Length

CMD_AOP_1

, AO

, 1

, Passive

, DA_OUT

, 0

, N1 11

, 1

, Relinquish_default

, DA_Pri_Array

, DA_Pri_Array_Offset

, DA_Pri_In_Use

, DA_Pri_In_Use_Offset

, 40.56

, DA_Pri_Array_1

, 0

, DA_Pri_in_use_1

, 0

BACnet PTP Serial Driver Manual

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Appendix A.5. BACnet State Text Preload

BACnet Multistate Objects have a State_Text property. This property is defined as an array of character
strings representing descriptions of all possible states of the Present_Value. The number of descriptions
matches the number of states defined in the Number_Of_States property. The Present_Value, interpreted
as an integer, serves as an index into the array.

When Multistate Objects are configured on a BACnet Server it is necessary to define the State_Text
property. This section illustrates how to define the State_Text character strings and how to associate
these definitions with Multistate Server Map Descriptors.

The maximum permitted length of any State_Text string is 50 characters.

Appendix A.5.1. Method 1 – Using an Offset/User Table

//set up a look up table

Offset_Table

Offset_Table_Name

, Table_String

, Table_Index_Value

FIRE_ALRM_TEXT

, SYSTEM READY

, 1

FIRE_ALRM_TEXT

, ALARM

, 2

FIRE_ALRM_TEXT

, MAINTENANCE

, 3

FIRE_ALRM_TEXT

, OFF-LINE

, 4

FIRE_ALRM_TEXT

, IN SERVICE

, 5

FIRE_ALRM_TEXT

, OTHER

, 6 Data_Arrays

Data_Array_Name

, Data_Format

, Data_Array_Length

DA_MI_01

, UINT16

, 100

Map_Descriptors

Map_Descriptor_Name

, Data_Array_Name

, Data_Array_Offset

, Function

, Node_Name

CMD_MI_01

, DA_MI_01

, 0

, Passive

, N1 11

, Data_Type

, Object_ID

, Length

, State_Text_Array

, MI

, 1

, 1

, Fire_Alrm_Text

Appendix A.5.2. Method 2 – Using a Single Data Array

Data_Arrays

Data_Array_Name

, Data_Format

, Data_Array_Length

DA_MI_01

, UINT16

, 100

DA_STATE_TXT

, BYTE

, 200

Preloads

Data_Array_Name

, Preload_Data_Value

, Preload_Data_Format

, Preload_Data_Index

DA_STATE_TXT

, MyState1 MyState2 MyState3
MyState4 MyState5 MyState6

, String

, 0
Map_Descriptors

Map_Descriptor_Name

, Data_Type

, Object_ID

, Function

, Data_Array_Name

, Node_Name

, Length

, State_Text_Array

CMD_MI_01

, MI

, 1

, Passive

, DA_MI_01

, N1 11

, 1

, Da_State_Txt

Valid values are 1
to 16.

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Appendix A.5.3. Using Intrinsic Reporting for a Multistate Value

To use Intrinsic Reporting for a Multistate value, it is necessary to classify each of the states as either
Normal, Alarm or Trouble. This is done by adding another column to the Offset_Table, called
Table_User_Value. Each state is then classified by inserting one of the following values in its row:

0 = normal
1 = alarm
2 = fault

//set up a look up table

Offset_Table

Offset_Table_Name

, Table_String

, Table_Index_Value

, Table_User_Value

FIRE_ALRM_TEXT

, SYSTEM READY

, 1

, 0

FIRE_ALRM_TEXT

, ALARM

, 2

, 1

FIRE_ALRM_TEXT

, MAINTENANCE

, 3

, 2

FIRE_ALRM_TEXT

, OFF-LINE

, 4

, 2

FIRE_ALRM_TEXT

, IN SERVICE

, 5

, 0

FIRE_ALRM_TEXT

, OTHER

, 6

, 2

NOTE: The state value (Table_Index_Value) is an enumerated value between 1 and 16. Zero is not

a valid value, but since many client side configurations will wake up with values of zero,
the BACnet Server will treat a value of zero as a normal value (i.e. not as an alarm or fault
value).

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Appendix A.6. COV and Intrinsic Reporting

The COV (Change of Value) and Intrinsic Reporting services are two distinct ways in which point values
can be reported to a client workstation as they change, i.e. in an event-driven opposed to a polling
method. This can increase performance dramatically compared to polling method alone. It also reduces
network traffic significantly.

The services are suited to different purposes:

• COV is suited to value updates. On analog points the sensitivity can be set using the COV_Increment
property. Only changes larger than the COV_Increment value will be reported.

• Intrinsic Reporting is used for alarming. It is implemented via Notification_Class objects, which can
receive subscriptions from client workstations that add themselves to the RecipientList property of a
Notification_Class object. Notifications are done using ConfirmedEventNotification or
UnconfirmedEventNotification. Intrinsic Reporting also allows for alarms to be acknowledged (using
the AcknowledgeAlarm service) and for all subscribed client workstations to be notified of alarm
acknowledgements (using EventNotifications of type ACK_NOTIFICATION).

Appendix A.6.1. Notes on COV Configuration

• No special configuration entries are needed to enable COVs. The service is enabled by default for all
protocols except MSTP. Most client workstations will automatically subscribe to all points once they
discover that the FieldServer supports COV services. This only applies to BACnet Objects - Property
subscribes are not supported by the FieldServer. COV only works for BACnet Map Descriptors with
length set to 1. If length is not specified, then it defaults to 1, so this is only a problem where length
has been specified as greater than 1.

• The Node_Option parameter can be configured to enable or disable COV. An example configuration
is presented in Appendix A.7.3.

• For analog Server Map Descriptors, the user may optionally configure a COV_Increment value to
adjust the reporting threshold. If it is not set the COV_Increment defaults to zero.

• Change of Value (COV) Notifications are generated for all data objects for which a remote client has
issued a SubscribeCOV-Request. COV subscription is on a per-point basis. The SubscribeCOV­Request regulates whether Notifications are Confirmed or Unconfirmed. The remote client may also
write the COV_Increment property in order to control the deadband for changes in analog values. The
COV_Increment property can be initialized via the configuration file by setting the COV_Increment
Map Descriptor Property. The value set by the configuration is an initial value that is loaded on
startup. It would be replaced by any new value written by the Client.

Appendix A.6.2. Notes on Intrinsic Reporting Configuration:

• Intrinsic Reporting is managed by Notification Class objects. At least one Notification Class object
must be configured for Intrinsic Reporting to work.

• Each Data_Object that is to be monitored by Intrinsic Reporting must be linked to a Notification Class
object via the Notification_Class Map Descriptor Property. For analog points alarm limits must be set
up, and for binary points, the Input_Alarm_State must be set up.

• The Notification_Class object contains properties that allow a client workstation to modify rules
governing event reporting, such as Event_Type, days of week, start and end times etc.

• The RecipientLists are non-volatile, and subscriptions must be renewed on system restart.

BACnet PTP Serial Driver Manual

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Appendix A.7. Map Descriptor Examples
Appendix A.7.1. COV

// Change of Value

Map_Descriptors

Map_Descriptor_Name

, Data_Array_Name

, Data_Array_Offset

, Function

, Node_Name

, Data_Type

, Object_ID

, Ack_Required

SMD_NC_01

, DA_NC_01

, 0

, Passive

, Virtual_Dev_11

, NC

, 01

, -

Map_Descriptors

Map_Descriptor_Name

Description

Data_Array_Name

Data_Array_Offset

Function

Node_Name

Data_Type

Object_ID

Relinquish_Default

SMD_AI_01

, Room Temp

, DA_AI_01

, 0

, Passive

, Virtual_Dev_11

, AI

, 01

, -

State_Text_Array

, Notification_Class

, High_Alarm

, Low_Alarm

, Input_Alarm_State

, Confirmed

, COV_Increment

, -

, SMD_NC_01

, 100

, 10

, -

, Yes

, 1.0

Appendix A.7.2. Intrinsic Reporting

// Notification class Objects

Map_Descriptors

Map_Descriptor_Name

, Data_Array_Name

, Data_Array_Offset

, Function

, Node_Name

, Object_Type

, Object_Instance

, Ack_Required

SMC_NC_01

, DA_NC_01

, 0

, Passive

, Virtual_DEV_11

, NC

, 1

, Yes

SMC_NC_02

, DA_NC_01

, 1

, Passive

, Virtual_DEV_11

, NC

, 2

, No

Map_Descriptors

Map_Descriptor_Name

, Data_Array_Name

, Data_Array_Offset

, Function

, Node_Name

, Object_Type

, Object_Instance

, Notification_Class

SMD_AI_01

, DA_AI_01

, 0

, Passive

, Virtual_DEV_11

, AI

, 1

, SMC_NC_01

SMD_AO_01

, DA_AO_01

, 0

, Passive

, Virtual_DEV_11

, AO

, 1

, SMC_NC_02

Map_Descriptors

Map_Descriptor_Name

, Data_Array_Name

, Data_Array_Offset

, Function

, Node_Name

, Object_Type

, Object_Instance

, Notification_Class

SMD_DI_01

, DA_DI_01

, 0

, Passive

, Virtual_DEV_11

, BI

, 1

, SMC_NC_01

SMD_DO_01

, DA_DO_01

, 0

, Passive

, Virtual_DEV_11

, BO

, 1

, SMC_NC_02

Appendix A.7.3. Enable or Disable COV

Nodes

Node_Name

, Node_ID

, Protocol

, Node_Option

Virtual_Dev_11

, 11

, BACnet_IP

, COV_Disable

BACnet PTP Serial Driver Manual

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Appendix A.8. Reliability_Option

The Reliability_Option parameter selects the rules by which the BACnet server determines the Reliability
property of a BACnet object whose present value is read from a Remote Server Node.

There are two important events that can affect the reliability of a BACnet object:

• The responsible Remote Server Node is offline, i.e. the data cannot be updated.

• A BACnet write request has been received by the BACnet Server. This causes the corresponding

FieldServer data object to be expired until its value is updated by the next successful Read operation.

There are three options for translating these conditions to BACnet Reliability values:

Track_Object_Status

The Reliability property mirrors the internal data object state, i.e. if the Remote
Server Node is offline or the data is expired by a BACnet write, the Reliability
is marked Unreliable-Other.

Track_Node_Status
(default)

The reported reliability is good unless the Remote_Server_Node is offline, in
which case the Reliability is Unreliable-Other. Reliability is not affected by
data expiry following a BACnet write.

Always_Reliable

The BACnet Server always reports good data reliability, regardless of the
status of communications with the Remote Server Node.

Example

Adapters

Adapter

, Protocol

, Reliability_Option

N1

, BACnet_IP

, Track_Node_Status

NOTE: This setting applies to all BACnet Nodes configured for a given BACnet Connection.

BACnet PTP Serial Driver Manual

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Appendix A.9. Specifying ReadPropertyMultiple and WritePropertyMultiple Transactions Using
Linked Map Descriptors

The ReadPropertyMultiple (RPM) and WritePropertyMultiple (WPM) BACnet services allow many objects
and attributes to be read and written in a single transaction. Since FieldServer Map Descriptors can only
refer to a single object type and address range, an RPM or WPM transaction can be constructed by
linking multiple Map Descriptors. This is done using the following components:

• An active read or write Map Descriptor that defines the behavior of the RPM or WPM transaction

via:

o Function, e.g. Rdbc, Arcs, Wrbc, Wrbx
o Scan_interval
o Timeout
o Length

• Any number of Linked Map Descriptors specifying additional objects and data array locations to

be included in the transaction. Each Linked Map Descriptor is specified with the following
settings:
o Linked_Map_Descriptor – this is a reference by name to the active Map Descriptor described

above, which controls the transaction

o Function – Passive_Client
o Length

The number of Linked Map Descriptors is limited by the maximum message length allowed for the
BACnet driver in question. When too many Map Descriptors have been linked a
SEGMENTATION_NOT_SUPPORTED error message will be generated on the first poll attempt. This
message will recommend splitting the RPM or WPM transaction into multiple transactions, e.g.:

DRV->BACnet : Linked Map Desc. "CMD_WPM" is too long.
Message Segmentation not supported.
Please split the transaction into multiple Linked Map Descriptors.

BACnet PTP Serial Driver Manual

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Example

Map_Descriptors

Map_Descriptor_Name

, Object_Type

, Property

, Function

, Data_Array_Name

, Data_Array_Offset

, Node_Name

, Address

, Length

, Write_Priority

, Linked_Map_Descriptor

CMD WPM

, AO

, -

, Wrbc

, DA WPM

, 0

, N1 1

, 1

, 2

, 7

, -

Map_Descriptor_Name

, Object_Type

, Property

, Function

, Data_Array_Name

, Data_Array_Offset

, Node_Name

, Address

, Length

, Write_Priority

, Linked_Map_Descriptor

CMD WPM 1

, AO

, -

, Passive_Client

, DA WPM

, 3

, N1 1

, 4

, 3

, 8

, CMD WPM

CMD WPM 2

, AO

, -

, Passive_Client

, DA WPM

, 7

, N1 1

, 8

, 4

, 10

, CMD WPM

CMD WPM 3

, Device

, Max_Master

, Passive_Client

, DA WPM

, 12

, N1 1

, 1

, 1

, 10

, CMD WPM

CMD WPM 4

, Device

, Max_Info_Frames

, Passive_Client

, DA WPM

, 13

, N1 1

, 1

, 1

, 10

, CMD WPM

CMD WPM 5

, BO

, -

, Passive_Client

, DA BOP

, 0

, N1 1

, 0

, 10

, 11

, CMD WPM

// ReadPropertyMultiple

Map_Descriptors

Map_Descriptor_Name

, Object_Type

, Property

, Function

, Data_Array_Name

, Data_Array_Index

, Node_Name

, Address

, Length

, Write_Priority

, Linked_Map_Descriptor

CMD RPM

, AO

, -

, Rdbc

, DA RPM

, 9

, N1 1

, 1

, 2

, -

, - Map_Descriptor_Name

, Object_Type

, Property

, Function

, Data_Array_Name

, Data_Array_Index

, Node_Name

CMD RPM 3

, Device

, Max_Master

, Passive_Client

, DA RPM

, 0

, N1 1

CMD RPM 4

, Device

, Max_Info_Frames

, Passive_Client

, DA RPM

, 1

, N1 1

CMD RPM 2

, AO

, -

, Passive_Client

, DA RPM

, 2

, N1 1

CMD RPM 1

, AO

, -

, Passive_Client

, DA RPM

, 6

, N1 1

, Address

, Length

, Write_Priority

, Linked_Map_Descriptor

, 1

, 1

, -

, CMD RPM

, 1

, 1

, -

, CMD RPM

, 8

, 4

, -

, CMD RPM

, 4

, 3

, -

, CMD RPM

NOTE:

• For the Present_Value property it is permissible to set a Map Descriptor length >1. This will cause a read of the Present_Value property of

consecutive BACnet objects of the type defined by this Map Descriptor.

• The number of properties that can be read or written at once is limited by the maximum APDU message length.

• Message segmentation is not supported.

Configure an active read or write Map Descriptor and give it a
unique name. This Map Descriptor will be referred to by all other
Map Descriptors forming part of the multiple property transaction.

Configure a Map Descriptor for each Object and Property. These are component
Map Descriptors forming part of the composite Map Descriptor CMD WPM above.

Set the function to Passive_Client.

Set Linked_Map_Descriptor to the name of the active
read or write Map Descriptor governing the transaction.

These map descriptors
form part of the read
transaction defined by
Map Descriptor CMD
RPM above.

BACnet PTP Serial Driver Manual

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Appendix B. Troubleshooting

Appendix B.1. Debugging a BACnet Connection

• If duplicate Object_Instances are configured in the FieldServer, the second call of the Instance will
overwrite the first one. This may cause a BACnet Object to be “lost.”

• If the Node Name configured on the BACnet Server Side of the configuration is not being indicated as
the Device Name on the BACnet SCADA system, then the FieldServer is not communicating with the
SCADA system. If the Device Object's name is being indicated, but the Present_Value shows
question marks, then it is likely that the Client side of the FieldServer is not communicating.

• Extra memory is required to store Map Descriptors that have the active/inactive text parameters
specified. If the defaults are appropriate, do not specify these parameters. This will save memory and
allow more Map Descriptors to be created.

• When a BACnet_PTP connection is established, and the connection is broken abruptly (for instance a
power down), the DEVICE might not know immediately that this happened. If the FieldServer is then
powered up again, it might take several seconds (up to 60 seconds) before polling will start again.

Appendix B.2. BACnet Error Response Decoding

BACnet reports errors in the following format:
T02> 10/22 02:57 HEXDUMP : ERROR_PDU

T02> 10/22 02:57 0x19d2d 50 97 0f 91 02 91 2a
T02> 10/22 02:57 BACnet -> Unexpected ERROR_PDU : err_class=2 err_code=42

These can be decoded using the following tables:

Appendix B.2.1. BACnet Error CLASS

Device

0

Object

1

Property

2

Resources

3

Security

4

Services

5

BACnet PTP Serial Driver Manual

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Appendix B.2.2. BACnet Error CODES for Error Class OBJECT

Other

0

Authentication failed

1

Configuration in progress

2

Device busy

3

Dynamic creation not supported

4

File access denied

5

Incompatible security levels

6

Inconsistent parameters

7

Inconsistent selection criterion

8

Invalid data type

9

Invalid file access method

10

Invalid file start position

11

Invalid operator name

12

Invalid parameter data type

13

Invalid time stamp

14

Key generation error

15

Missing required parameter

16

No objects of specified type

17

No space for object

18

No space to add list element

19

No space to write property

20

No vt sessions available

21

Property is not a list

22

Object deletion not permitted

23

Object identifier already exists

24

Operational problem

25

Password failure

26

Read access denied

27

Security not supported

28

Service request denied

29

Timeout

30

Unknown object

31

Unknown property

32

Unknown vt class

34

Unknown vt session

35

Unsupported object type

36

Value out of range

37

Vt session already closed

38

Vt session termination failure

39

Write access denied

40

Character set not supported

41

Invalid array index

42

Invalid index

42

BACnet PTP Serial Driver Manual

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Appendix C. Vendor Information

Appendix C.1. McQuay

McQuay Units are shipped with a default Device instance of the last 6 digits of the McQuay Serial
number.

Appendix C.2. Trane

When new points are added to the FieldServer it is important to restart the Summit Workstation or BCU,
otherwise these new points may not be seen by the FieldServer.

Disconnect the FieldServer from the BACnet network when transferring images to the BCU.
Connection to a Trane BCU requires the purchase of a RTS to DB9M convertor. This is available from

Sierra Monitor (Part # FS-8917-02).

Appendix C.3. Liebert

Polling BACnet addresses that are not configured for Liebert systems may cause the connection to fail in
older versions of Liebert. Please contact your Liebert supplier for more information.

Appendix C.4. Automated Logic Corporation

When an ALC module is powered up, and it does not detect valid BACnet/MSTP traffic on its MSTP port,
then the module goes into a terminal mode and MSTP communications will not be initiated.

When connecting the FieldServer to an ALC BACnet/MSTP module, always start the FieldServer first.
Wait until the RUN Led is flashing on the FieldServer before powering up the MSTP module.

Appendix C.5. Honeywell EBI

Honeywell EBI cannot process EventNotifications with ACK_Required set to 1. The ACK_Required
property of Notification Class Map Descriptors configured for use with EBI must therefore be set to 0.

BACnet PTP Serial Driver Manual

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Appendix D. Reference

Appendix D.1. Object_Type Legal Values – Abbreviation Descriptions

AI

ANALOG_INPUT

AO

ANALOG_OUTPUT

AV

ANALOG_VALUE

BI

BINARY_INPUT

BO

BINARY_OUTPUT

BV

BINARY_VALUE

MI

MULTI_STATE_INPUT

MO

MULTI_STATE_OUTPUT

MV

MULTI_STATE_VALUE

NC

NOTIFICATION_CLASS_OBJECT

DEVICE

DEVICE

Appendix D.2. Property Legal Values

Legal Value

Description

Object_Identifier

This property is a numeric code that is used to identify the object. It is unique
within the BACnet Device that maintains it.

Object_List

Relevant to Device Object Type. This property is a BACnetARRAY of
Object_Identifiers, one Object_Identifier for each object within the device that is
accessible through BACnet services. An Object_Identifier is composed of Object
Type and Object Instance and must be unique within a BACnet Device, e.g. Object
Type = Analog Input, Object Instance = 3.

Present_Value

This property contains the present value of the Input / Output / Value.

Object_Name

Character string providing the name of a BACnet object. The set of characters
used in the Object_Name is restricted to printable characters. The Object_Name is
determined by the Map_Descriptor_Name.

Description

Character string describing a BACnet object. This can be defined by the user to
give additional detail about the Object.

Out_of_service

The Out_Of_Service property, of type BOOLEAN, is an indication whether (TRUE)
or not (FALSE) the physical input that the object represents is not in service. This
means that the Present_Value property is decoupled from the physical input and
will not track changes to the physical input when the value of Out_Of_Service is
TRUE. In addition, the Reliability property and the corresponding state of the
FAULT flag of the Status_Flags property shall be decoupled from the physical
input when Out_Of_Service is TRUE. While the Out_Of_Service property is TRUE,
the Present_Value and Reliability properties may be changed to any value as a
means of simulating specific fixed conditions or for testing purposes. Other
functions that depend on the state of the Present_Value or Reliability properties
shall respond to changes made to these properties while Out_Of_Service is
TRUE, as if those changes had occurred in the physical input.

Event_State

The Event_State property, of type BACnetEventState, is included in order to
provide a way to determine if this object has an active event state associated with
it. If the object supports intrinsic reporting, then the Event_State property shall
indicate the event state of the object. If the object does not support intrinsic
reporting, then the value of this property shall be NORMAL. Other values: FAULT,
OFF-NORMAL, HIGH-LIMIT, LOW-LIMIT, LIFE-SAFETY-ALARM.

Units

This property contains the units associated with the Present_Value property.

BACnet PTP Serial Driver Manual

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Legal Value

Description

Reliability

The Reliability property, of type BACnetReliability, provides an indication of
whether the Present_Value or the operation of the physical input in question is
"reliable" as far as the BACnet Device or operator can determine and, if not, why.
The following values are supported:
NO_FAULT_DETECTED, UNRELIABLE_OTHER

Priority_Array

This property relates to Output and Value Object Types and is a read only array
that contains prioritized commands or NULLs in the order of decreasing priority.
The highest priority (lowest array index) with a non-NULL value is the active
command.

State_Text

Relevant to Multistate Object Types: This property is a BACnetARRAY of
character strings representing descriptions of all possible states of the
Present_Value. The number of descriptions matches the number of states defined
in the Number_Of_States property. The Present_Value, interpreted as an integer,
serves as an index into the array.

Number_Of_States

Relevant to Multistate Object Types: this property sets the total number of states
for which descriptions will be returned as defined under the State_Text property.
The number of states will be determined automatically by the largest state number
used when configuring the Offset Table (refer to Appendix A.5).

Max_Master

Relevant to BACnet MS/TP Device Object Type: The Max_Master property, of
type Unsigned, shall be present if the device is a master node on an MS/TP
network. The value of Max_Master specifies the highest possible address for
master nodes and shall be less than or equal to 127. If the Max_Master property is
not writeable via BACnet services, its value shall be 127.

Max_Info_Frames

Relevant to BACnet MS/TP Device Object Type: The Max_Info_Frames property,
of type Unsigned, shall be present if the device is a node on an MS/TP network.
The value of Max_Info_Frames specifies the maximum number of information
frames the node may send before it must pass the token. If Max_Info_Frames is
not writable or otherwise user configurable, its value shall be 1.

Active_Text

Relevant to Binary Object Types: This property, of type CharacterString,
characterizes the intended effect of the ACTIVE state of the Present_Value
property from the human operator's viewpoint. The content of this string is a local
matter, but it is intended to represent a human-readable description of the ACTIVE
state. For example, if the physical input is a switch contact, then the Active_Text
property might be assigned a value such as "Fan 1 On".

Inactive_Text

This property, of type CharacterString, characterizes the intended effect of the
INACTIVE state of the Present_Value property from the human operator's
viewpoint. The content of this string is a local matter, but it is intended to represent
a human-readable description of the INACTIVE state. For example, if the physical
input is connected to a switch contact, then the Inactive_Text property might be
assigned a value such as "Fan 1 Off".

Description

A character string giving more information about the Object associated with the
Present_Value property.

Firmware_revision

The firmware revision of the application.

Relinquish_Default

This property is the default value to be used for the Present_Value property when
all command priority values in the Priority_Array property have a NULL value.

BACnet PTP Serial Driver Manual

Page 30 of 34

Appendix D.3. BACnet Vendor ID

BACnet Vendor Name: Sierra Monitor Corporation
BACnet Vendor ID: 37

Appendix D.4. Units

Unit

Variation 1

Variation 2

Type

amperes

amps

A

Electrical

ampere-seconds

Energy

amperes-per-meter

Electrical

amperes-per-square-meter

Electrical

ampere-square-hours

Energy

ampere-square-meters

Electrical

bars

Pressure

becquerels

Other

btus

Energy

btus-per-hour

Power

btus-per-pound

Enthalpy

btus-per-pound-dry-air

Enthalpy

candelas

Light

candelas-per-square-meter

Light

centimeters

Length

centimeters-of-mercury

Pressure

centimeters-of-water

Pressure

cubic-feet

Volume

cubic-feet-per-day

Volumetric Flow

cubic-feet-per-hour

Volumetric Flow

cubic-feet-per-minute

Volumetric Flow

cubic-feet-per-second

Volumetric Flow

cubic-meters

Volume

cubic-meters-per-day

Volumetric Flow

cubic-meters-per-hour

Volumetric Flow

cubic-meters-per-minute

Volumetric Flow

cubic-meters-per-second

Volumetric Flow

currency1

Currency

currency10

Currency

currency2

Currency

currency3

Currency

currency4

Currency

currency5

Currency

currency6

Currency

currency7

Currency

currency8

Currency

currency9

Currency

cycles-per-hour

Frequency

cycles-per-minute

Frequency

days

Time

decibels

Electrical

decibels-a

Other

decibels-millivolt

Electrical

decibels-volt

Electrical

degree-days-Celsius

Temperature

degree-days-Fahrenheit

Temperature

degrees-angular

Other

degrees-Celsius

Deg-C

Deg_C

Temperature

degrees-Celsius-per-hour

Other

degrees-Celsius-per-minute

Other

degrees-Fahrenheit

Deg-F

Deg_F

Temperature

degrees-Fahrenheit-per-hour

Other

degrees-Fahrenheit-per-minute

Other

degrees-Kelvin

Deg-K

Deg_K

Temperature

degrees-Kelvin-per-hour

Temperature

degrees-Kelvin-per-minute

Temperature

degrees-phase

Electrical

delta-degrees-Fahrenheit

Temperature

delta-degrees-Kelvin

Temperature

farads

Electrical

feet

Length

feet-per-minute

Velocity

BACnet PTP Serial Driver Manual

Page 31 of 34

Unit

Variation 1

Variation 2

Type

feet-per-second

Velocity

foot-candles

Light

grams

Mass

grams-of-water-per-kilogram-dry-air

Humidity

grams-per-cubic-centimeter

Other

grams-per-cubic-meter

Other

grams-per-gram

Other

grams-per-kilogram

Other

grams-per-liter

Other

grams-per-milliliter

Other

grams-per-minute

Mass Flow

grams-per-second

Mass Flow

grams-per-square-meter

Other

gray

Other

hectopascals

Pressure

henrys

Electrical

hertz

Hz Frequency

horsepower

HP Power

hours

Time

hundredths-seconds

Time

imperial-gallons

Volume

imperial-gallons-per-minute

Volumetric Flow

inches

Length

inches-of-mercury

Pressure

inches-of-water

Pressure

joule-per-hours

Power

joules

Energy

joule-seconds

Other

joules-per-cubic-meter

Other

joules-per-degree-Kelvin

Entropy

joules-per-kilogram-degree-Kelvin

Entropy

joules-per-kilogram-dry-air

Enthalpy

kilobecquerels

Other

kilo-btus

Energy

kilo-btus-per-hour

Power

kilograms

kg Mass

kilograms-per-cubic-meter

Other

kilograms-per-hour

Mass Flow

kilograms-per-kilogram

Other

kilograms-per-minute

Mass Flow

kilograms-per-second

Mass Flow

kilohertz

kHz Frequency

kilohms

Electrical

kilojoules

Energy

kilojoules-per-degree-Kelvin

Entropy

kilojoules-per-kilogram

Energy

kilojoules-per-kilogram-dry-air

Enthalpy

kilometers

Length

kilometers-per-hour

Velocity

kilopascals

Kpa Pressure

kilovolt-ampere-hours

Energy

kilovolt-ampere-hours-reactive

Energy

kilovolt-amperes

kilovolt-amps

KVA

Electrical

kilovolt-amperes-reactive

KVAR

Electrical

kilovolts

Electrical

kilowatt-hours

kWh Energy

kilowatt-hours-per-square-foot

Other

kilowatt-hours-per-square-meter

Other

kilowatt-hours-reactive

Energy

kilowatts

kW Power

liters

Volume

liters-per-hour

Volumetric Flow

liters-per-minute

Volumetric Flow

liters-per-second

Volumetric Flow

lumens

Light

luxes

Light

megabecquerels

Other

mega-btus

Energy

megahertz

MHz Frequency

megajoules

Energy

megajoules-per-degree-Kelvin

Entropy

BACnet PTP Serial Driver Manual

Page 32 of 34

Unit

Variation 1

Variation 2

Type

megajoules-per-kilogram-dry-air

Enthalpy

megajoules-per-square-foot

Other

megajoules-per-square-meter

Other

megavolt-ampere-hours

Energy

megavolt-ampere-hours-reactive

Energy

megavolt-amperes

megavolt-amps

Electrical

megavolt-amperes-reactive

MVAR

Electrical

megavolts

Electrical

megawatt-hours

MWh

Energy

megawatt-hours-reactive

Energy

megawatts

MW Power

megohms

Electrical

meters

Length

meters-per-hour

Velocity

meters-per-minute

Velocity

meters-per-second

Velocity

meters-per-second-per-second

Acceleration

micrograms-per-cubic-meter

Other

micrograms-per-liter

Other

microgray

Other

micrometers

Length

microsiemens

Electrical

microsieverts

Other

microsieverts-per-hour

Other

miles-per-hour

Velocity

milliamperes

milliamps

Electrical

millibars

Pressure

milligrams

Mass

milligrams-per-cubic-meter

Other

milligrams-per-gram

Other

milligrams-per-kilogram

Other

milligrams-per-liter

Other

milligray

Other

milliliters

Volume

milliliters-per-second

Volumetric Flow

millimeters

Length

millimeters-of-mercury

Pressure

millimeters-of-water

Pressure

millimeters-per-minute

Velocity

millimeters-per-second

Velocity

milliohms

Electrical

million-standard-cubic-feet-per-day

Volumetric Flow

million-standard-cubic-feet-per-minute

Volumetric Flow

millirems

Other

millirems-per-hour

Other

milliseconds

Time

millisiemens

Electrical

millisieverts

Other

millivolts

Electrical

milliwatts

Power

minutes

Time

minutes-per-degree-kelvin

Other

mole-percent

Other

months

Time

nanograms-per-cubic-meter

Other

nephelometric-turbidity-unit

Other

newton

Force

newton-meters

Torque

newton-seconds

Other

newtons-per-meter

Other

no-units

No_Units

None

Other

ohm-meters

Electrical

ohm-meter-squared-per-meter

Electrical

ohms

Electrical

parts-per-billion

Other

parts-per-million

Other

pascals

Pressure

pascal-seconds

Other

percent

Other

percent-obscuration-per-foot

Other

percent-obscuration-per-meter

Other

BACnet PTP Serial Driver Manual

Page 33 of 34

Unit

Variation 1

Variation 2

Type

percent-per-second

Other

percent-relative-humidity

% RH; %RH

Percent RH; Percent RH

Humidity

per-hour

Frequency

per-mille

Other

per-minute

Other

per-second

Other

pH

Other

pounds-force-per-square-inch

PSI

pounds-force-per-sq-inch

Pressure

pounds-mass

Mass

pounds-mass-per-day

Volumetric Flow

pounds-mass-per-hour

Mass Flow

pounds-mass-per-minute

Mass Flow

pounds-mass-per-second

Mass Flow

power-factor

PF Electrical

psi-per-degree-Fahrenheit

Other

radians

Other

radians-per-second

Other

revolutions-per-minute

Other

seconds

Secs S Time

siemens

Electrical

siemens-per-meter

Electrical

sieverts

Other

square-centimeters

Area

square-feet

Area

square-inches

Area

square-meters

Area

square-meters-per-Newton

Other

standard-cubic-feet-per-day

Volumetric Flow

teslas

Electrical

therms

Energy

thousand-cubic-feet-per-day

Volumetric Flow

thousand-standard-cubic-feet-per-day

Volumetric Flow

ton-hours

Energy

tons

Mass

tons-per-hour

Mass Flow

tons-refrigeration

Power

us-gallons

Gallons

Volume

us-gallons-per-hour

Volumetric Flow

us-gallons-per-minute

GPM

Volumetric Flow

volt-ampere-hours

Energy

volt-ampere-hours-reactive

Energy

volt-amperes

Volt-Amps

VA

Electrical

volt-amperes-reactive

VAR Electrical

volts

voltage

Electrical

volts-per-degree-Kelvin

Electrical

volts-per-meter

Electrical

volt-square-hours

Energy

watt-hours

wH Energy

watt-hours-per-cubic-meter

Other

watt-hours-reactive

Energy

watts

W Power

watts-per-meter-per-degree-Kelvin

Other

watts-per-square-foot

Light

watts-per-square-meter

Light

watts-per-square-meter-degree-kelvin

Other

webers

Electrical

weeks

Time

years

Time

BACnet PTP Serial Driver Manual

Page 34 of 34

Appendix D.5. BACnet Specific Statistics

Stat

Description

Resolution

Link Control

A “who-is” link control message was
send or received.

It is normal to receive a few link control
messages. If the number is higher than the
transmit/receive messages, however, there
may be a problem with lost communications.

Unsupported
Properties

A request for an unsupported
property was received.

This is not an error. BACnet clients often poll
all properties of a particular object to
determine which properties are supported.

Segmentation
Not Supported

Data was requested but the response
would have exceeded the maximum
size of the APDU and could not be
sent using an un-segmented
message.

This is not an error – the BACnet client will
use a different method to read data from the
FieldServer.

Sequence Error

Invoke ID of a reply did not match the
Invoke ID of the poll.

You should not see this message. It normally
indicates a configuration error.

Write Access
Denied

A write to an object was denied.

This typically happens when trying to write to
an Input Object that is not Out-Of-Service. It
is not possible to write to Input Objects.

Exception Errors

A BACnet Service was denied
because it is not supported.

This may be a problem on the Client system.
Consult the PIC statement to determine what
services are supported.