The TU812V1 is a 50V Compact Module Termination Unit (MTU) designed specifically for the ABB System 800xA® automation system, primarily used for field signal connection and ModuleBus distribution within the S800 I/O system. As a crucial component of the S800 I/O system, this product serves as a bridge connecting field instrument signals to the upper-level control system. It is characterized by high density, high reliability, easy installation, and maintenance, and is widely used in automation control systems across industries such as power generation, process industries, and manufacturing.
The TU812V1 is a passive unit, meaning it contains no electronic processing circuitry. Its core functions include:
Providing 16 signal channels via field wiring terminals.
Carrying and distributing the ModuleBus to I/O modules and downstream termination units.
Automatically generating the correct address for connected I/O modules through position signal shifting.
Physically preventing misinsertion through a mechanical keying mechanism, ensuring I/O module type compatibility.
This termination unit features a compact design, supports DIN rail mounting, and is suitable for space-constrained cabinet layouts. It is a key component in building highly reliable, modular I/O stations.
2. Product Design Features and Benefits
2.1 Compact Structure and High-Density Connection
The TU812V1 employs a highly integrated design, achieving 16 signal connection points within a volume of only 64mm (W) × 170mm (H) × 64mm (D). It interfaces with I/O modules via a 25-pin D-Sub connector, significantly saving cabinet space and enhancing system integration density.
2.2 ModuleBus Distribution and Automatic Address Generation
This MTU not only provides physical connections but also incorporates part of the ModuleBus circuitry. It reliably transmits ModuleBus signals to the connected I/O module and continues the bus to the next MTU, forming a reliable daisy-chain bus topology. Furthermore, through a unique "position signal shift" mechanism, the TU812V1 can automatically assign the appropriate station address to the I/O module mounted on it, simplifying system configuration and commissioning.
2.3 Mechanical Keying for Misinsertion Prevention
To ensure physical system security, the TU812V1 is equipped with two mechanical keys. Each key has 6 different positions, allowing for a combination of 36 distinct mechanical configurations. This design ensures that only I/O modules matching the key configuration can be inserted, fundamentally preventing hardware damage or system failures caused by incorrect module installation.
2.4 Robust Mounting and Grounding Design
DIN Rail Mounting: Supports mounting on standard DIN rails (e.g., EN 60715 35x7.5 or 35x15) and features a latching device for secure installation.
Grounding Connection: Grounding is achieved via the DIN rail, meeting electrical safety requirements and providing good Electromagnetic Compatibility (EMC) performance.
2.5 Flexible Mounting Orientation
The product supports both horizontal and vertical mounting orientations, providing flexibility for cabinet layout. Note the operational temperature limitations:
3. Application Scenarios and Compatibility
The TU812V1 is a standardized component within the ABB System 800xA® and Symphony Plus control system architectures, primarily applied in scenarios requiring highly reliable, modular distributed I/O.
3.1 Typical Application Areas
Process Industries: Continuous process control in oil & gas, chemicals, pharmaceuticals, etc.
Power Industry: Monitoring, control, and data acquisition in power plants, transmission, and distribution systems.
Manufacturing: Discrete and batch process control in automotive, food & beverage, metals, etc.
Marine & Shipping: Suitable for ship control systems, meeting marine certification requirements.
3.2 System Compatibility
The TU812V1 is designed for the S800 I/O System and is compatible with various S800 series I/O modules, including analog input/output (e.g., A810, A830A), digital input/output (e.g., D810, D880), and special function modules (e.g., DP820 Profibus-DP interface module). This broad compatibility allows for flexible construction of I/O stations adapted to different signal types.
4. Installation, Configuration & Maintenance Guidelines
4.1 Installation Steps
Rail Mounting: Snap the TU812V1 onto a standard DIN rail until the latch audibly clicks into place, ensuring reliable grounding.
Field Wiring: Connect field instrument signal wires to the removable terminal blocks on the front of the MTU. Follow relevant electrical codes during wiring, paying attention to signal polarity (e.g., +/-).
Module Installation: Based on the I/O module type to be used, configure the key slots on the MTU using the provided mechanical keys. After setting the keys to the correct position, insert the corresponding I/O module.
Bus Connection: Connect the ModuleBus via the backplane or bus cable, ensuring communication link continuity.
4.2 Mechanical Key Configuration
Configuring the keys is a critical pre-installation step. Key positions correspond one-to-one with I/O module types. Incorrect configuration will prevent module insertion, thereby avoiding hardware mismatch. Configuration tables are typically provided with the I/O modules or can be found in the product manual.
4.3 Maintenance Considerations
Hot Swap: The TU812V1 itself is a passive unit, but whether connected I/O modules support hot swapping should be verified in the specific module's manual. Exercise caution when inserting/removing modules during system operation.
Cleaning: With power disconnected, clean the product surface using a dry, lint-free cloth.
Replacement: If an MTU needs replacement, disconnect power and field signals first, then remove the terminal blocks and modules, release the DIN latch, and extract the unit.
5. Interpretation of Safety & Environmental Certifications
The numerous international certifications obtained by the TU812V1 reflect its exceptional product quality and applicability.
CE Marking: Indicates the product conforms to EU health, safety, and environmental protection standards, allowing free circulation within the European Economic Area.
cULus & ATEX Zone 2: Signifies the equipment is suitable for use in Class I Division 2 or Zone 2 hazardous areas with potentially explosive atmospheres, meeting North American and European explosion protection requirements.
Marine Certifications (ABS, BV, DNV-GL, LR): Demonstrate suitability for the harsh environments of offshore facilities and ships.
RoHS & WEEE Compliance: Adherence to EU directives restricting hazardous substances and mandating recycling of waste electrical equipment, highlighting ABB's commitment to environmental protection.
