FS-8700-21 – LonWorks

FieldServer Driver – FieldBus


The LonWorks driver allows the FieldServer to transfer data to and from devices using LonWorks protocol. The FS-B30 Series and FS-B4011 can handle up to 4096 Network Variables and the FS-B2011 up to 1000 which can be of the Standard Network Variable Types (SNVT) and/or User-defined Network Variable Types (UNVT). The FieldServer LonWorks device can be used with explicit and/or implicit addressing and can be bound to a maximum of 15 other LonWorks nodes. The FS-B30 Series and FS-B4011 can handle a maximum of 4096 explicitly addressed nodes and the FS-B2011 up to 1000. The FieldServer currently supports a default of 63 network variable aliases to avoid network variable connection constraints.

The FieldServer can transfer data (Network Variables) in two ways.

  • It can poll (request data from) other devices at a regular interval.
  • It can send Network Variable Updates
    • At a regular interval
    • When the data has changed
    • In throttled mode using minimum and maximum send time and change on delta parameters.

The FieldServer is capable of being configured by Network Management Tools such as LonMaker. For binding (implicit mode), a Network Management Tool is necessary to create the bindings. It is possible to place a FieldServer into a Network for explicit communications without using a Network Management Tool, but this requires intimate knowledge of the network in question.

The external interface file (.XIF) for the FieldServer can be uploaded from the FieldServer for the particular application. The FieldServer differs from most other LonWorks devices in that its XIF file is not fixed due to varying applications. The list of points available to the network will vary depending on the other networks connected to the FieldServer, and the requirements of the particular application. The recommended procedure for obtaining the XIF file for the FieldServer is to upload it.

The FieldServer provides the capability of defining multiple functional blocks, but only a single LonMark object. The user can create multiple functional blocks or a LonMark object by filling out the Node Self-Documentation String and the respective Network Variable Self-documentation String fields in the FieldServer configuration file.

The following table summarizes the FieldServer LonWorks driver’s capabilities:

FS-B2011 FS-B30 FS-B4011
Number of NetworkVariables [1] 1000 4096 4096
Address Table Entries 15 15 15
Network Variable Aliases 63 63 63
Number of Domain Tables [2] 2 2 2
Support for SNVTs [3] Yes Yes Yes
Support for UNVTs Yes Yes Yes
Explicit Addressing Yes Yes Yes
Implicit Addressing Yes Yes Yes
XIF file Yes Yes Yes
Supports Polled NetworkVariables Yes Yes Yes
Supports Network VariableUpdates Yes Yes Yes
Supports ConfigurationProperties [4] Yes Yes Yes
Supports Node and NetworkVariable Self-documentation Strings Yes Yes Yes
Support for SCPTs [5] Yes Yes Yes
Network Management Toolssuch as LonMaker Supported Yes Yes Yes
Commissioning withoutNetwork Management Tool Supported [6] Yes Yes Yes
Service Pin Supported Yes Yes Yes
LonMark Object andFunctional Profiles definition [7] Yes Yes Yes
  1. The length of Network Variable names and complexity of the configuration may limit the actual number of usable Network Variables
  2. One of the two domains is the zero domain used by Network Management Tools
  3. SNVT Master List Version 11 is supported
  4. Implemented with Configuration Network Variables
  5. Only selected SCPTs are supported, extra SCPTs can be added on a per configuration basis
  6. Explicit Addressing Only
  7. Only approved LonMark objects are supported, see www.lonmark.org
Fieldserver Mode Nodes Comments
Clientor Server 1 TheFieldServer can only represent one LonWorks device on the LonWorks Network.
ALonWorks device is unique in terms of its Neuron Chip Identification Number.


Formal Driver Type

Client or Server


Compatibility Matrix

FieldServer Model Compatible with thisdriver
FS-B2010 No
FS-B2011 Yes
FS-B30 Yes
FS-B40 Yes


Connection Information

Connection type: FTT-10 Free Topology Network Transceiver
Baud Rates: 78125 bps (bits per second)
Hardware interface: PCC10 LonWorks adapter ISA card ( FS-X40 )
Built in LonWorks FTT-10 interface ( FS-X2011 )


Devices tested

Device Tested (FACTORY, SITE)
LonMaker for Windows V3.1 Factory/Site
TAC Xenta Factory/Site
Electronic Systems USA Factory
Echelon ILon 100 Site
Plexus Technologies Site
Invensys I/A Series Factory
Circon UHC 300 (and others) Factory
Distech Site
PureChoice Nose Factory/Site
Honeywell Factory/Site
…and many others


Connection configurations

The connection diagram below shows how the FieldServer FS-X20, FS-X30 and FS-X40 are connected to a LonWorks network:


Connection Notes

The 2-wire twisted-pair connection to the network is polarity insensitive. The FTT-10 network is a free topology network which supports star, loop and / or bus wiring connections. Please refer to the FTT-10A Free Topology Transceiver User’s Guide from Echelon Corporation for recommended wiring practices if necessary.


Communications functions – Supported functions at a glance:

Data Types Supported

FieldServer Data Type Description (or Device Data Type)
Integers ( Long, short, signed, unsigned ) SNVTs and UNVTs can be presented, stored and moved intoany FieldServer data type


Read Operations supported

FieldServer as a Client FieldServer as a Server
Polled Network Variables: Polled NetworkVariables:
-Send Network VariableFetch -Respond to NetworkVariable Fetch
-Send Network Variable Poll -Respond to NetworkVariable Poll


Write (Control) Operations supported

FieldServer as a Client FieldServer as a Server
Network VariablesUpdates: Network VariablesUpdates:
-Send Network VariableUpdates -Accept Network VariableUpdates


Unsupported Functions and Data Types

Function Reason
Programming messages FieldServer is a data transfer device, and as such,programming messages are not required
Direct Memory Read / Writes under user control The driver uses the Echelon MIP which handles directmemory read and writes
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