FS8705-11 – FA403 Serial Protocol

FieldServer Driver – Serial
FA403 Serial’ Protocol



The FA403 by the ‘Steam & Condensate Group’ of Armstrong International Inc. is designed to monitor the status of wireless connected remote steam trap monitoring devices. The FA403 is equipped with a serial port and it sends status info over this port.

This driver is intended to monitor the steam trap status of multiple devices connected to a FA403.

The following brief notes describe the driver capability

  • The driver processes ‘Transmitter Status’ Messages and ignore all others
  • The driver is a passive client – listening passively for messages from the FA403.
  • The driver stores the date and time of the last message that was received. This data can be served to a remote client using another protocol.
  • The driver stores the status and the id info of the last message that was received. This data can be served to a remote client using another protocol.
  • Each time a Transmitter Status message is received the driver validates the message. If valid the driver extracts the System ID and the Transmitter ID. These are used to build an index into a Data Array where the status information will be stored. Thus each system_id / transmitter_id combination can have its status stored at a unique location in a data array. Depending on how the server (say Modbus) is configured, it will be possible to allocate a unique address to each devices’ status. For example status of 1,1 could be associated with register 40001, of 1,2 with 40002 etc.
  • The driver can be configured to accept / ignore messages containing status information for specific system_id / transmitter_id combinations for a range of combinations.
  • The driver expects messages to be sent in hex format from the FA403
Fieldserver Mode Nodes Comments
Passive Client 1 Messages do not contain destination and source node addresses. Therefore only one FA403 Serial Receiver can be connected to each port.


Formal Driver Type

Passive Client


Compatibility Matrix

FieldServer Model Compatible with this driver
FS-x2010 Yes
FS-x2011 Yes
FS-x40 Yes
FS-X30 Yes


Connection Information

Connection type: EIA485
Baud Rates: Driver Supports : 110; 300; 600; 1200; 2400; 4800; 9600; 19200; 28800; 38400; 57600; 115200 Baud
FA403 Serial Receiver supports: 9600
Data Bits: Driver Supports : 7,8
FA403 Serial Receiver supports: 8
Stop Bits: Driver Supports : 1, 2
FA403 Serial Receiver supports: 1
Parity: Driver Supports : Odd, Even, None
FA403 Serial Receiver supports: None
Hardware interface: N/A
Multidrop Capability: No


Devices tested:

Device Tested (FACTORY, SITE)
FA403 Serial Receiver Customer Site


Connection configurations

FS40 shown as representing FS20, FS30 and FS40

Multiple FA403 Systems can be connected. One per port.

Multiple upstream protocols and connection supported. See list of FieldServer Drivers.


Communications functions

The driver only processes messages sent in Hex mode.

All message beside Status Messages are ignored.

The driver does not send any messages in response.



This driver was developed by Chipkin Automation Systems (CAS), a FieldServer Approved Integrator(r). CAS are proud to provide support for the driver. For support please call CAS at (866) 636-5400.

If you liked this post;
  • Please consider subscribing to our RSS feed