Triconex 8112 High-Density Remote Expansion Chassis | Invensys Tricon

TRICONEX 8112 High-Density Remote Expansion Chassis

The TRICONEX 8112 is a high-density remote expansion chassis for Triconex Tricon safety instrumented systems (SIS). Designed to extend I/O capacity beyond the main chassis, the 8112 houses up to 16 I/O modules and supports Triple Modular Redundancy (TMR) architecture with triplicated RS-485 I/O expansion bus communication. When paired with Remote Extender Modules (RXM) such as the 4211, the 8112 can be located up to 7.5 miles (12 km) from the main chassis via single-mode fiber, enabling distributed I/O architectures in large facilities.

• Type: High-Density Remote Expansion Chassis
• I/O Capacity: Up to 16 I/O modules (digital, analog, HART, and specialized modules)
• Termination Panel Support: 32-point termination panels
• Redundancy: Triple Modular Redundancy (TMR) with 2-out-of-3 voting logic
• Communication: Dual RS-485 I/O expansion bus ports (375 kbps); Ethernet/IP (2 Mbps)
• Remote Distance: Up to 7.5 miles (12 km) with RXM fiber modules; up to 100 ft standard; up to 1,000 ft restricted
• Power Supply Compatibility: 8310 (120 VAC/VDC), 8311 (24 VDC), 8312 (230 VAC)
• Hot-Swappable: Yes — power supplies and I/O modules can be replaced online
• Mechanical Keying: Prevents incorrect module insertion in each slot
• Mounting: 19-inch rack mount
• Dimensions: 19″ W × 22.75″ H × 17.75″ D (48.3 × 57.8 × 45.1 cm)
• Weight: 54.0 lbs (24.5 kg) empty chassis
• Operating Temperature: 0°C to +60°C (32°F to 140°F); extended range -40°C to +70°C available
• Humidity: 5%–95% RH, non-condensing
• Chassis Fabrication: Black zinc-plated and welded cold-rolled steel
• SIL Certification: SIL 3 (IEC 61508)
• Certifications: CE, UL, ISO, RoHS

Installation Guide

1. Mount the 8112 in a 19-inch control cabinet at the remote location. Allow minimum 6 inches clearance for ventilation.
2. Install power supply modules (8310/8311/8312) in the dedicated power slots.
3. Install I/O modules in the I/O slots. Use 8105 blank panels to fill unused slots and maintain EMC integrity.
4. Connect the I/O expansion bus from the main chassis to the 8112 using Tricon bus cables (9000 series) for local installations (< 100 ft).
5. For remote installations (> 100 ft): install 4210-3 primary SRXM in the main chassis and 4211-3 remote SRXM in the 8112. Connect via single-mode fiber with ST connectors.
6. Verify all three TMR channels show PASS indicators. Test fiber link integrity using optical power meters.

FAQ

Q: What is the difference between 8111 and 8112?
A: The 8111 is the expansion chassis (local, connected via copper bus cables, typically within 100 ft of main chassis). The 8112 is the remote expansion chassis (designed for fiber-linked remote I/O up to 7.5 miles). Both support the same I/O modules and TMR architecture.

Q: Can the 8112 operate as a standalone controller?
A: No. The 8112 is an expansion chassis only — it does not house main processors. It relies on the main chassis (8110) for control logic execution. The 8112 extends I/O capacity to remote locations.

Q: How many 8112 chassis can I connect to one main chassis?
A: A Tricon system supports up to 14 additional chassis (total 15 chassis including main). This can be a mix of 8111 (local expansion) and 8112 (remote expansion) chassis, limited by I/O bus capacity and power budget.

Selection Tips

• Choose 8112 when I/O modules need to be located far from the main control room (e.g., remote compressor stations, tank farms, hazardous area enclosures).
• For local expansion within the same control room or adjacent cabinet, use 8111 to save fiber infrastructure costs.
• Calculate total power consumption of all I/O modules and select appropriate power supplies (8310/8311/8312). Maintain N+1 redundancy.
• Always use 8105 blank panels in unused slots. Do not leave slots open — this compromises EMC and environmental protection.
• Plan fiber cable runs with spare fiber pairs for future expansion or repair. Use single-mode fiber with ST connectors for 4211 RXM pairs.