Siemens S55376-C116 Replacement for Desigo Series

Product Overview

Siemens S55376-C116 Replacement for Desigo Series: Seamless Transition & Smooth Migration

The Siemens S55376-C116 is a Desigo series communication module designed for building automation and industrial control environments. As facilities managers and system integrators face the challenge of maintaining aging Desigo-based HVAC and BMS infrastructure, the S55376-C116 serves as a critical replacement and upgrade solution for discontinued or end-of-life communication modules within the Siemens Desigo ecosystem. Whether you are migrating from an older Desigo PX or Desigo Insight platform, or simply replacing a failed communication node in an existing rack, this module provides the compatibility, reliability, and physical form factor required for a smooth, low-downtime retrofit.

The S55376-C116 supports BACnet/IP communication protocol, making it fully interoperable with modern building management systems and SCADA platforms. Its standardized DIN rail or panel mounting footprint ensures it fits directly into existing Desigo controller cabinets without requiring structural modifications to the control panel. Field engineers can reuse existing wiring harnesses and terminal blocks, significantly reducing installation labor and the risk of wiring errors during the changeover.

When replacing a legacy Desigo communication module such as the S55376-C115 or earlier S55376-series variants, the S55376-C116 maintains backward compatibility with the Desigo PX controller family, including the PXC series room automation stations. This means your existing Desigo programming, object lists, and BACnet device configurations can be retained with minimal re-commissioning effort. System integrators working on multi-zone HVAC projects will appreciate that the module’s BACnet MS/TP and BACnet/IP dual-protocol support allows it to bridge legacy field bus segments to modern IP-based supervisory networks without requiring a full controller replacement.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful migration from a legacy Desigo communication infrastructure to a modernized, IP-connected architecture typically involves more than just swapping the communication module. During the retrofit process, system integrators commonly work with a range of complementary Siemens Desigo components to ensure full system continuity.

The Desigo PXC room automation station controllers — such as the PXC36-E.D or PXC64-U — are frequently upgraded in parallel with the S55376-C116 communication module, as the controller firmware and object database must be aligned with the new module’s BACnet/IP addressing scheme. In multi-zone projects, the Desigo PXA30-W wireless access point module is often introduced alongside the S55376-C116 to extend the BACnet network to wireless field devices without running new cable infrastructure.

On the power supply side, the Siemens SITOP PSU100S 24 V DC power supply unit is a common companion component in Desigo cabinet retrofits, providing stable 24 V DC rail power to the new communication module and associated I/O expansion modules. For I/O expansion, the Desigo PXX-L I/O extension modules are typically retained or upgraded in tandem, as their terminal assignments and object mappings are preserved when the S55376-C116 replaces the legacy communication node.

Communication cabling between the S55376-C116 and the supervisory Desigo Insight or Desigo CC management station is handled via standard Cat5e or Cat6 Ethernet, replacing the older RS-485 trunk cable. In installations where the existing RS-485 MS/TP field bus must be retained for downstream legacy devices, a Siemens OCI600 or OCI611 interface converter is used to bridge the MS/TP segment to the new IP backbone managed by the S55376-C116.

For programming and commissioning, the Siemens Desigo Tool Set (DTS) software running on a standard engineering laptop connects to the S55376-C116 via the RJ-45 Ethernet port, eliminating the need for a dedicated programming cable or serial adapter that older Desigo modules required. This simplifies on-site commissioning and reduces the specialist tooling that field engineers must carry to site.

In control cabinet environments where signal isolation is required between the BACnet/IP network and legacy 4–20 mA analog I/O loops, a Phoenix Contact or Weidmüller signal isolator module is commonly installed in the same DIN rail section as the S55376-C116, ensuring clean signal integrity across the upgraded communication backbone.

Retrofit Guidance FAQ

Q: Can I reuse my existing RS-485 wiring when installing the S55376-C116?
Yes. The S55376-C116 retains the RS-485 MS/TP terminal block interface of its predecessors. Your existing field bus wiring, including shielded twisted-pair cable and termination resistors, can be reconnected directly to the same terminal positions without modification.

Q: Do I need to reprogram the Desigo PXC controller after replacing the communication module?
In most cases, no full reprogramming is required. The BACnet object database and room automation logic stored in the PXC controller are independent of the communication module. However, you will need to update the BACnet device instance number and IP address parameters in the S55376-C116 to match your network configuration using the Desigo Tool Set software.

Q: Is the S55376-C116 compatible with Desigo CC (formerly Desigo Insight)?
Yes. The S55376-C116 communicates via BACnet/IP, which is the native protocol for both Desigo CC and Desigo Insight management stations. No additional gateway or protocol converter is required for supervisory integration.

Q: What is the physical installation space requirement?
The S55376-C116 uses the same DIN rail mounting footprint as the modules it replaces in the Desigo S55376 series. No cabinet modification, additional DIN rail section, or enclosure expansion is required for a direct replacement installation.

Q: How is the module powered, and do I need to change the power supply?
The S55376-C116 operates on 24 V AC/DC, identical to the legacy modules it replaces. Your existing 24 V power supply rail and wiring can be reused without modification.

Q: Can the S55376-C116 bridge a legacy MS/TP field bus to a new BACnet/IP network?
Yes. The dual-protocol capability of the S55376-C116 allows it to simultaneously communicate on the BACnet MS/TP field bus (RS-485) and the BACnet/IP Ethernet network, making it an ideal bridge device during phased migration projects where not all field devices are upgraded simultaneously.

Warranty Assurance

Every Siemens S55376-C116 unit shipped by TOPNLMS is covered by a 12-month warranty from the date of delivery. Prior to dispatch, each unit undergoes a functional inspection and power-on verification test to confirm communication interface integrity and module identification. Units that do not pass inspection are not shipped.

In the event of a confirmed hardware defect within the warranty period, TOPNLMS provides a replacement unit or full refund, subject to return inspection. Our technical support team is available to assist with installation queries, compatibility confirmation, and commissioning guidance via email and phone. Typical response time for technical inquiries is within 1 business day.

Stock is held in our Xiamen warehouse and is available for immediate dispatch. Standard international shipping lead time is 3–7 business days depending on destination. Express shipping options are available for urgent replacement requirements to minimize system downtime.

For bulk procurement, OEM sourcing, or project-based purchasing inquiries, please contact our sales team directly to discuss pricing, lead times, and documentation requirements including test reports and certificates of conformity.