Haffmans OGM RS Gateways


Description of the Haffmans OGM Gehaltemeter Protocol Converter

The CAS-2700-31 Gateway is a specific converter for Haffmans OGM Gehaltemeters. It polls the OGM sensor’s RS232 serial port for status, real time measurements, and configuration data then makes the information available through both BACnetIP and Modbus (RTU and TCP).
The gateway serves data from a Haffmans OGM O2 sensors as Modbus, BACnet or web data simultaneously. Simply use the data you want and ignore the others.
The Gateway connects to a Haffmans OGM O2 sensor, reads data and stores it internally. When a remote system requests the data, it serves in a form that is appropriate to the protocol. In the event that the connection to the Haffmans OGM O2 sensor is lost or data cannot be read, the gateway signals it to the remote data client.
The gateway requires minimal configuration and can be considered a plug and play component of a system. It is ready to operate out of the box with the default configuration.


  • UL and ULc approved
  • 10/100BaseT with RJ-45 connector
  • 1x RS232 Port
  • 1x RS485 Port (Different Models have additional ports)
  • 2MBytes flash memory, 8MBytes of SDRAM
  • Power: 5-24VDC
  • Operating Temperature: 0 to 70 C
  • Dimensions: 4.2″ x 3.25″ x 1″
  • LEDs: Link, Speed/Data, Power


Max Nodes Supported

Gateway Mode Nodes Comments
Client 1 Only 1 Haffmans OGM O2 sensor per connection
Server 0 Not supported or documented


Haffmans OGM RS Connection configuration Diagram

Monitor and control Haffmans OGM oxygen sensor using BACnet, Modbus, or Web.

Driver Operation

The driver can be configured to execute any of the commands in the ‘supported function’ list. The
data sent is stored internally in the Gateway and is made available to other protocols (Modbus
RTU, Modbus TCP, BACnet IP, and HTML) .
The frequency with each data point is read is configurable. The driver retries on errors or
timeouts. If the data cannot be read then after a configurable length of time it is marked as out of
The driver reports operating statistics and issues on a web page and maintains a log that can be
uploaded by HTTP or FTP

Data sheets and Manuals

Haffmans OGM Gehaltemeter gateway datasheet.
Haffmans OGM Gehaltemeter Leaflet
Haffmans OGM Gehaltemeter Case Study
Haffmans OGM Gehaltemeter Brochure
Haffmans Optical OGM Technology Presentation



Haffmans website
Haffmans OGM gas applications

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