Multiport Gateway

The FieldServer Multiport Protocol Gateway (FS-B35XX) is an extremely flexible tool for integrators looking to connect devices to the cloud and on different physical networks, using different links, and speaking different protocols.

Enjoy the benefits of the cloud connectivity through FieldPoP™. The EZ Gateway Modbus to BACnet is FieldPoP-enabled, meaning all EZ Gateways can be registered to FieldPoP, Sierra Monitor’s device cloud for the IIoT. The FieldPoP web interface lets users remotely access, in a secure fashion, the FS-GUI that are available locally on the EZ Gateway. These applications offer functionality for configuration, monitoring, logging, security, diagnostics, and updates.

Learn more about FieldServer and FieldPoP capabilities »

With support for 1,000 points (upgradable to 10,000), the Multiport Gateway can easily handle multiple protocol drivers and multiple translations simultaneously with no slowdown in performance. The product includes four serial connections (two RS-232, two RS-485), two 10/100 Ethernet ports, and a LonWorks (Free Topology - FT) port. The multiple ports and support for simultaneous protocol execution allow the Multiport Gateway to be used in the most complex integration scenarios. The availability of the second Ethernet port enables the integrator to connect a PC to download configuration changes without disturbing the system connections and without the additional cost of an external hub for the protocol gateway.

Multiport Protocol Gateway units can be configured in the field, with all the necessary instructions and software included with the product. If the user prefers the unit to be pre-configured prior to delivery, Sierra Monitor offers a custom configuration service.

The Multiport Gateway is approved across a variety of standards, including UL-916, CE, and RoHS. Protocol certifications include the BTL Mark, LonMark, and DNP3 Conformance. These approvals and certifications assure our customers that we carry only the highest quality of standards-compliant products.

With multi-protocol flexibility, ease-of-use, wide deployment, and world-class technical support, the Multiport Protocol Gateway is truly the Swiss Army knife of systems integration.

Multiport Gateway

  • FieldPoP Device Cloud support: Register your Multiport Gateway to the FieldPoP interface for remote access to local applications, configuration, and device management
  • 140+ protocols - Allows integrator to complete any project with any protocol on-time
  • BTL, LonMark Certifications - Full compliance with standards allows integrator to complete projects quickly without downstream interoperability issues
  • 1000 to 10000 points – Sized for the largest integration projects
  • RS-485 x 2, Ethernet x 2, LonWorks (FT), RS-232 x 2: Flexible and lower cost connectivity options for the integrator
  • FieldServer Toolbox – Perform quick diagnostics, troubleshooting, easy IP details set-up, and status updates
  • Memory Utilization Monitoring – View application memory statistics to enable optimal matching of device models and configurations to specific applications
  • Firmware Updates – Easily update the firmware or configuration of the Multiport Gateway through a USB flash drive or the Toolbox

Specifications for Multiport Gateway

Field Connections

  • Ethernet Ports – 2
    • 100 BaseT RJ45 connector (auto MDIX and sensing) with ESD protection
  • Serial Ports – 5
    • 2 x RJ45 RS-232 galvanically isolated with ESD protection
    • 2 x RS-485 galvanically isolated with ESD protection
    • 1 x RJ45 RS-232 system port
  • LonWorks – 1
    • FTT-10 twisted pair
    • 1000 Network variable capability
    • LonWorks service pin
  • Auxiliary Ports – 2
    • 2 x USB ports
    • Expansion: Fieldbus connectors available for selected protocols


  • Drivers available for a wide range of Ethernet and serial protocols

LED Indicators

  • Power, Run, System Error, Configuration Error, Node Offline
  • Ethernet connection – Link OK, Tx/Rx communication activity
  • RS-232/RS-485 – Tx/Rx communication activity
  • LonWorks – activity


  • Operating temperature: 32o to 140oF (0o to 60oC)
  • Relative humidity: 10-90% RH non-condensing

Power Requirements

  • 24 VAC (+/- 10%) or 12-30 VDC @ 12W


  • Configuration/Diagnostic utilities
  • Base system has 1000 point capability (upgradable to 10,000 points)

Physical Dimensions (H x W x D)

  • 2.0 x 6.3 x 5.4 in. (5.0 x 16.0 x 13.7 cm)
  • 2.5 lb. (1.5 Kg)

Mounting Options

  • Desktop, Wall, Panel
  • Optional: DIN rail


  • Memory upgrade for additional data points
  • Custom Configuration Services


  • CE Marked
  • CSA Certified to UL-916 Standard and CSA @ 22.2
  • DNP3 Conformance
  • FCC Part 15
  • LonMark Certified
  • Modbus Tested
  • RoHS Compliant
  • GOST-R Certified

Protocol Drivers

Supporting over 140 protocols, the Multiport Protocol Gateway (FS-B35XX) from Sierra Monitor can connect a variety of facility devices to various networks using two or more of the following protocols:


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How to Purchase the Multiport Gateway

You can directly contact us to receive a quote: