TB850 3BSC950193R1 | ABB S800 I/O CEX-Bus Terminator

Product Overview

The ABB TB850 (3BSC950193R1) serves as the indispensable termination component for the CEX-Bus (Communication Extension Bus) within the S800 I/O and AC 800M controller architecture. This passive hardware unit prevents signal reflection and maintains the correct characteristic impedance of the high-speed communication line. Without a properly installed TB850, the bus suffers from data corruption and intermittent communication timeouts. We provide this unit as 100% Brand New and Original, ensuring your industrial network operates with peak signal clarity and zero data loss.

Technical Specifications

The TB850 utilizes a precision-matched impedance circuit to stabilize the bus:

• Product ID: 3BSC950193R1

• Type Designation: TB850

• Function: CEX-Bus End Termination

• Net Width: 50 mm

• Net Height: 16 mm

• Net Depth / Length: 55 mm

• Net Weight: 0.04 kg

• Mounting: Direct plug-in to CEX-Bus port

• Compatibility: ABB AC 800M Controllers and S800 I/O Communication Interfaces

Engineering Advantages

• Elimination of Signal Reflection: The TB850 absorbs traveling waves at the end of the CEX-Bus line. This prevents "signal bounce" which otherwise creates destructive interference and causes the controller to lose contact with I/O modules or communication interfaces.

• High-Speed Data Stabilization: By maintaining a constant impedance across the entire bus length, the TB850 allows the CEX-Bus to operate at its maximum rated baud rate. This stability supports the fast update cycles required for complex PID control and safety-related logic.

• Ultra-Compact Plug-and-Play Design: The module features a small 16mm height profile. It plugs directly into the final communication port of the cluster, requiring no additional wiring or external power. This simplifies commissioning and reduces the chance of manual wiring errors.

• Zero-Latency Passive Operation: Because the TB850 uses passive components, it introduces no processing delay into the network. It provides instant, hardware-level stabilization from the moment of power-up, ensuring the bus remains ready for immediate data exchange.

• Robust Mechanical Fit: The connector pins utilize high-quality plating to ensure a low-resistance contact point. The mechanical housing snaps firmly into place, resisting the vibrations common in heavy industrial environments like power plants or chemical processing facilities.

FAQs

• Where exactly should I install the TB850?

  You must install the TB850 at the very last physical port of the CEX-Bus extension. Every communication bus requires termination at both ends to function correctly; the TB850 handles the "far end" termination of the extension line.

• What happens if I forget to install the bus terminator?

  Omission of the TB850 typically results in "Bus Error" alarms in the DCS software. You will likely experience intermittent communication failures, where I/O modules appear and disappear from the network randomly due to signal noise and reflections.

• Does the TB850 require any software configuration?

  No. The TB850 is a purely hardware-based component. Once you plug it into the correct port, it begins stabilizing the bus immediately. No firmware updates or IP addressing are required.

• Can I use the TB850 for standard Ethernet ports?

  No. The TB850 is specifically engineered for the ABB CEX-Bus protocol and physical interface. Plugging it into an RJ45 Ethernet port or other communication types will result in hardware mismatch and potential damage to the pins.