SMC Networks FieldServer FS-8700-16 BACnet PTP Release note

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
1BACnet PTP Description.....................................................................................................................5
2Driver Scope of Supply .......................................................................................................................5
2.1 Supplied by Sierra Monitor Corporation .........................................................................................5
2.2 Provided by supplier of 3rd party equipment...................................................................................5
3Hardware Connections........................................................................................................................6
4Data Array Parameters........................................................................................................................7
5Configuring 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
6Configuring 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-232
1
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
8TX
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
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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
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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
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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
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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
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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
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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
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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

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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 SubscribeCOV-
Request 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.