For engineers and technicians responsible for maintaining aging but critical industrial control systems, dealing with legacy components is a reality. The ABB TB820V2 3BSE013208R1 cluster modem is a perfect example. This guide provides a practical, step-by-step overview for sourcing authentic modules, integrating them into an existing Advant OCS, and understanding the options when the component is no longer available.
Pre-Procurement: Verification and Compatibility Check
Warning: Working with legacy control systems requires expertise. Always refer to the original system documentation.
1. Confirm the Exact Requirement
The part number 3BSE013208R1 is specific. Before searching, confirm this is the correct module by checking:
- Existing Hardware: Match the part number on the module that needs replacement.
- System Documentation: Check the original Advant OCS design documents, bill of materials, or wiring diagrams.
- Compatibility: The TB820V2 is designed for MasterBus 300 (MB300) networks. Verify that your system uses this protocol.
2. Assess the System Architecture
Understand the modem's role in your network:
- Is it a central modem in the main control rack?
- Is it a remote modem in a field enclosure?
- Is the system configured for redundancy (requiring a pair of modems)?
Step 1: Sourcing the Module - Navigating the Legacy Market
Sourcing a discontinued component requires caution to avoid counterfeit or faulty parts.
1. Check ABB's Official Lifecycle Status
First, check the official ABB website or contact ABB support directly to confirm the product's status. It is almost certainly classified as "Classic" or "Obsolete." This means ABB no longer manufactures it. However, they may be able to recommend a migration path or an authorized supplier of refurbished parts.
2. Source from Specialized Industrial Automation Suppliers
The most reliable sources for legacy components are reputable suppliers who specialize in obsolete ABB parts. Look for suppliers that:
- Offer a Warranty: A supplier offering a warranty (e.g., 1 year) is more confident in the quality of their parts.
- Provide Testing Reports: They should be able to provide a data sheet or a test report confirming the module is fully functional.
- Have Technical Expertise: They understand the product and its application, not just the part number.
3. Extreme Caution with Unofficial Channels
Avoid general online marketplaces where the risk of counterfeit products is very high. A faulty modem can cause communication loss to a critical part of your plant.
Step 2: Hardware Installation and Wiring
Safety First: Always follow lockout/tagout (LOTO) procedures. De-energize the rack before installing or removing any module.
- Rack Power Down: Power down the entire rack or station where the modem will be installed.
- Module Insertion: The TB820V2 is typically a plug-in module. Carefully insert it into the correct slot in the Advant OCS rack, ensuring it is firmly seated.
- Local Device Connection: Connect the short-haul serial cable from the modem to the communication port of the local device (e.g., the Advant controller or a remote SPIET800 interface). This is usually a sub-D connector or terminal block connection.
- Long-Distance Line Connection: Connect the long-distance twisted-pair cable to the modem's "Line" terminals. Observe correct polarity (Tip and Ring). Using a shielded cable is crucial.
- Grounding: Properly ground the modem and the cable shield according to the manual to ensure noise immunity and surge protection.
- Power Up: Re-apply power to the rack.
Configuration and Commissioning
The TB820V2 is generally a protocol-specific device (MB300) and often requires little to no software configuration. Commissioning is primarily a hardware and wiring check.
- Visual Indicators: After power-up, check the modem's status LEDs. Typically, a "Power" LED should be on, and "Carrier Detect" or "Receive" LEDs should indicate activity once the link is established.
- Loopback Test: If supported, a loopback test can be performed to verify the modem's basic functionality.
- End-to-End Test: The most effective test is to verify communication with the remote end. Using the engineering station (Advant Station), check if the remote I/O station or device is visible online and that data is being exchanged correctly.
Troubleshooting Common Issues
- No Communication:
- Check Power: Verify both modems (local and remote) are powered.
- Check Wiring: Verify the long-distance cable for breaks or shorts. Check polarity.
- Check Addresses: Ensure the device addresses on the MB300 network are correct and unique.
- Intermittent Communication:
- Noise: Likely caused by EMI. Verify cable shielding is grounded at one end only. Ensure separation from power cables.
- Faulty Cable: The long-distance cable may be damaged. Perform a megger test to check insulation resistance.
- High Error Rate:
- Distance: The link may be at the extreme end of its operational range.
- Signal Quality: The signal may be degraded. A line analyzer may be needed to check signal integrity.
Considering Modern Alternatives: Migration Paths
If sourcing legacy modems becomes unsustainable, consider a migration strategy:
- Serial-to-Ethernet Converter: Use a robust industrial protocol converter (e.g., Moxa) to convert the MB300 serial signal to Ethernet. The serial side connects to the existing controller, and the Ethernet side uses the plant network to communicate with the remote end, where another converter translates it back to serial. This leverages modern infrastructure.
- System Upgrade: The long-term solution is to plan a phased upgrade of the control system to a modern platform like ABB's System 800xA, which uses native Ethernet and fiber optics.
Conclusion
Integrating a ABB TB820V2 3BSE013208R1 modem requires careful sourcing, correct installation, and methodical testing. For facilities relying on legacy Advant OCS systems, maintaining these communication links is essential for operational continuity. While a migration to modern technology is the end goal, a reliable source for genuine legacy components and a disciplined approach to maintenance are key to bridging the gap until that upgrade can be executed.
