Wiesemann & Theis W&T 58631 Replacement for Com Server Series

Product Overview

Wiesemann & Theis W&T 58631 Replacement for Com Server Series: Seamless Transition to Modern Ethernet Connectivity

The W&T 58631 Com Server has long served as a reliable serial-to-Ethernet gateway in industrial automation environments, enabling RS-232, RS-485, and RS-422 serial devices to communicate over TCP/IP networks. As legacy infrastructure ages and original units reach end-of-life or become increasingly difficult to source, plant engineers and system integrators face the challenge of maintaining uptime while transitioning to modern, supportable hardware. TOPNLMS supplies verified replacement and upgrade solutions for the W&T 58631, ensuring your serial communication infrastructure continues to operate without costly downtime or full system redesigns.

The W&T 58631 is widely deployed in SCADA systems, building automation, energy metering, and distributed I/O architectures where legacy serial instruments — including RS-232 sensors, RS-485 Modbus RTU field devices, and RS-422 point-to-point links — must be integrated into Ethernet-based control networks. When the original unit fails or becomes unavailable, a direct-replacement Com Server must preserve the same serial interface pinout, baud rate range (up to 115,200 bps), and TCP/IP socket behavior to avoid reprogramming upstream PLCs or SCADA hosts.

Our replacement units are functionally equivalent to the W&T 58631 and support the same Wiesemann & Theis Com Server configuration protocol, allowing existing network parameters — IP address, port assignments, operating mode (TCP server, TCP client, UDP), and serial framing — to be transferred directly. This eliminates the need to modify Siemens S7-300 or S7-400 communication function blocks, Allen-Bradley DF1 driver configurations, or Schneider Electric Modbus TCP polling tables that reference the original device’s IP endpoint.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful W&T 58631 retrofit rarely involves the gateway alone. In most installations, the Com Server sits within a broader serial communication architecture that may include Wiesemann & Theis W&T 57750 Modbus TCP gateways handling additional RS-485 bus segments, or W&T 58200-series multi-port Com Servers where multiple serial channels share a single Ethernet uplink. When migrating a control cabinet that previously relied on the 58631 for a single RS-232 instrument link, engineers often simultaneously address adjacent W&T 57xxx-series digital I/O modules connected on the same DIN rail, ensuring the entire communication layer is refreshed in a single maintenance window.

On the field device side, the RS-485 bus connected to the 58631 typically carries Modbus RTU traffic from energy meters, variable frequency drives (VFDs), or temperature controllers. Replacing the gateway without verifying the RS-485 termination resistor and bias resistor settings on the terminal block can introduce communication errors. Our technical team can advise on correct termination for bus lengths up to 1,200 meters. Where the original installation used an RS-232 to RS-485 converter inline with the 58631, the replacement unit’s built-in multi-interface support often eliminates that intermediate converter entirely, simplifying the wiring harness inside the control cabinet.

For sites upgrading from older Siemens S5 or early S7-300 systems where CP 341 or CP 343-1 communication processors handled serial-to-Ethernet bridging, the W&T 58631 replacement provides a cost-effective path to preserve existing field wiring while connecting to a modern S7-1500 or S7-1200 controller via standard Modbus TCP or raw TCP socket communication — without replacing the entire backplane or rack assembly. Similarly, in Schneider Electric Modicon M340 or Premium PLC environments where NOE 771xx Ethernet modules poll serial field devices through a gateway, the replacement 58631 maintains the same IP endpoint, requiring no changes to the Unity Pro or EcoStruxure Machine Expert polling configuration.

Where installations include signal isolation requirements — common in long RS-485 runs across electrically noisy environments such as motor control centers — a DIN-rail-mounted signal isolator or surge protector on the serial port is recommended alongside the gateway replacement. This protects the new unit from ground loop currents that may have contributed to the failure of the original W&T 58631. TOPNLMS can supply compatible serial port surge protectors and isolation modules as part of a complete retrofit kit.

Retrofit Guidance FAQ

Q: Can I reuse the existing wiring when replacing the W&T 58631?
A: Yes. The replacement unit uses the same DB-9 or terminal block serial connector and standard RJ-45 Ethernet port. Existing cable assemblies can be reconnected directly. Verify RS-485 termination jumper positions match the original configuration before powering on.

Q: Do I need to reprogram my PLC or SCADA system after the swap?
A: No, provided you configure the replacement unit with the same IP address, TCP port number, and serial parameters (baud rate, data bits, parity, stop bits) as the original 58631. The upstream controller sees an identical network endpoint and requires no driver or program changes.

Q: Is the WuTility configuration tool compatible with the replacement unit?
A: The replacement unit supports the standard W&T Com Server web interface and is compatible with WuTility for network discovery and parameter backup/restore. Existing configuration export files from the original 58631 can be imported directly.

Q: What communication protocols are supported?
A: The unit supports Modbus TCP (as a transparent serial gateway), raw TCP socket (RFC 2217 virtual COM port), UDP datagram mode, and pair connection mode for point-to-point serial tunneling over IP. It does not perform Modbus RTU-to-TCP protocol conversion natively — the host application handles protocol framing.

Q: How much DIN rail space does the replacement unit require?
A: The replacement unit matches the original 58631 form factor (approximately 45 mm wide on DIN rail EN 60715). No additional panel cutouts or bracket modifications are required.

Q: What if my original unit used Power over Ethernet (PoE)?
A: Please confirm the PoE variant requirement at the time of order. Standard replacement units are powered via 12–24 VDC terminal. PoE-capable variants are available — specify when ordering to ensure the correct unit is shipped.

Warranty Assurance

Every W&T 58631 replacement unit supplied by TOPNLMS is covered by a 12-month warranty from the date of shipment. Prior to dispatch, each unit undergoes functional verification including serial interface loopback testing across RS-232, RS-485, and RS-422 modes, Ethernet connectivity confirmation, and web interface accessibility checks. Units are shipped with original or equivalent packaging to prevent transit damage.

In the event of a confirmed defect within the warranty period, TOPNLMS will arrange replacement shipment or issue a refund based on the customer’s preference. Our after-sales response target is within 24 business hours of fault report submission. For urgent production-line situations, expedited replacement dispatch is available — contact our sales team directly to arrange priority handling.

We maintain buffer stock of the W&T 58631 and functionally equivalent Com Server units to support rapid fulfillment for emergency breakdown scenarios. Standard lead time from order confirmation to shipment is 1–3 business days for in-stock units, with express international courier options available for time-critical plant maintenance situations.

All units are invoiced with full commercial documentation including packing list, commercial invoice, and certificate of conformity to support customs clearance for international shipments. HS code classification assistance is available upon request.