The ABB TB840A (3BSE037760R1) is a high-performance Modulebus Cluster Modem designed for the S800 I/O distributed process control system. This module serves as a critical fiber optic interface to the Optical ModuleBus, enabling robust communication between parent controllers and remote I/O clusters. The TB840A is specifically engineered for 1+1 redundant configurations, where it facilitates connection to redundant optical ModuleBus lines while maintaining a unified electrical ModuleBus for the connected I/O modules.
| Product Model | TB840A (3BSE037760R1) |
| Communication Protocol | Modulebus |
| Operating Mode | Slave |
| Power Consumption (24V) | 120 mA (typical) |
| Operating Temperature | 0 to +55 degC |
| Storage Temperature | -40 to +70 degC |
| Hazardous Area Ratings | C1 Div 2 cULus, C1 Zone 2 cULus, ATEX Zone 2 |
| Marine Certifications | ABS, BV, DNV-GL, LR |
The TB840A acts as a fiber optic interface to the Optical ModuleBus, allowing for the distribution of I/O clusters and enabling 1+1 redundant operation in S800 I/O systems.
While optimized for 1+1 redundancy, it serves as the standard interface for connecting I/O clusters to the Optical ModuleBus in various S800 I/O configurations.
The modem supports up to 12 I/O modules on the electrical ModuleBus and up to seven clusters on the fiber optic ModuleBus.
Our production line was down due to a faulty Bently Nevada monitor. We found it in stock here and they shipped it via DHL immediately. Back in operation within 48 hours—truly a lifesaver for our plant.
Finding brand new, original modules is critical for our safety. This team delivers factory-fresh components with full certification. Their commitment to only selling new products makes them our most trusted partner.
We have sourced Honeywell and Schneider parts here for two years. Every shipment arrives well-packaged with original factory seals intact. Clear communication and the best lead times in the industry.