Product Details
The ABB TB840A 3BSE037760R1, also cataloged as the TB840A Modulebus Cluster Modem, operates as a dedicated hardware component for optical-to-electrical signal conversion and I/O bus expansion within System 800xA and S800 I/O platforms. The module interfaces two optical ModuleBus fiber ports directly with electrical ModuleBus I/O backplane lines, managing supervisory power and redundant bus topology execution. It incorporates galvanic power isolation to protect downstream I/O clusters from line-side electrical transients.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | TB840A 3BSE037760R1 |
| Brand | ABB |
| Origin | Sweden |
| Weight | 0.2 kg (0.44 lbs) |
| Dimensions | 54 mm x 119 mm x 96 mm (2.13 in x 4.69 in x 3.78 in) |
| Operating Temp | 0 to +55 deg C |
| Power Consumption | 120 mA at 24 VDC (typical) |
| Communication Protocol | Modulebus (Optical and Electrical) |
| Operating Mode | Slave |
| Line Redundancy | Supported |
| Module Redundancy | Supported |
| Hot Swap | Supported |
| HI Controller Compatibility | Yes (Used with High Integrity Controllers) |
| Compatible MTUs | TU840 (Redundant TB840A, Dual ModuleBus), TU841 (Redundant TB840A, Single ModuleBus) |
Backplane Bus Communication Velocity and Deterministic Network Redundancy
The TB840A modem maintains deterministic signal propagation across optical and electrical ModuleBus segments, enabling high-density I/O expansion without introducing communication delays. Firmware flash compatibility ensures smooth integration across S800 I/O clusters and High Integrity (HI) safety controllers. When deployed on dual ModuleBus terminal units (TU840/TU841), the module continuously monitors link integrity and optical power levels, executing seamless bumpless failover between primary and secondary lines if signal degradation occurs.
Frequently Asked Questions
Q: Does the TB840A support hot-swapping under live operating conditions?
A: Yes. The TB840A allows live replacement on a powered ModuleBus terminal unit (such as TU840 or TU841) without disrupting communication on adjacent active modules.
Q: What power input protection features are built into the TB840A modem?
A: The module contains internal power input fuses along with isolated power supply circuitry that delivers regulated, surge-protected DC power to connected I/O module backplanes.
Field Installation Guidelines
- Mount the matching ModuleBus Terminal Unit (TU840 for dual ModuleBus or TU841 for single ModuleBus) onto the DIN rail before module insertion.
- Ensure optical fiber connectors (ST type) are clean and free of dust contamination before inserting into the optical ModuleBus ports.
- Observe ESD precautions by wearing an earth-grounded wrist strap prior to unboxing and inserting the unit into its terminal unit slot.
- Push the TB840A firmly into the MTU slot until the mechanical locking latch fully engages the base assembly.
- Connect external 24 VDC power through fused terminal blocks and verify that field cabling shields terminate at a single chassis ground lug.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
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