Description
The Rockwell Automation / ICS Triplex Trusted T8850 is a 40-Channel Analogue/Digital Output Field Termination Assembly (FTA) designed for the Trusted™ Triple Modular Redundant (TMR) Safety System. Installed in system enclosures, the T8850 serves as the signal interface unit between the field wiring devices (actuators, control valves, solenoids) and the Trusted TMR Analogue or Digital Output Modules (e.g., T8451 or T8461 cards).
Key Specifications & Identification
| Attribute | Details |
| Manufacturer | Rockwell Automation / ICS Triplex |
| Part / Model Code | T8850 |
| System Architecture | Trusted™ TMR (Triple Modular Redundant) Safety System |
| Module Category | Output Field Termination Assembly (FTA) |
| Channel Capacity | 40 Independent Output Channels |
| Signal Type Compatibility | Analogue Outputs (4–20 mA) & Digital Outputs (24 V DC) |
| Field Connection Type | Screw terminal blocks / Smart Connector interface |
| Redundancy Support | Dual / Companion FTA configuration for high-availability voting |
Primary System Functions
- TMR Signal Routing & Termination: Routes field wiring from 40 process output channels directly into high-density ribbon/cable interfaces connected to the Trusted TMR output module rack.
- Passive Isolation & Protection: Provides onboard line testing points, channel fusing options, and transient suppression to protect main chassis TMR processor cards against field short circuits or high-voltage surges.
- Dual Companion Configuration: Supports paired companion configurations to allow active/standby module swapping without interrupting output current or voltage to critical safety actuators.
- Line Monitoring Compatibility: Works in tandem with Trusted output modules to support line-fault diagnostics (detecting open circuits or field short circuits) across process loops.
Servicing & Installation Guidelines
- Field Power Isolation: Verify that external field excitation voltages (e.g., 24 V DC loop power) are de-energized or isolated before landing or removing field wires on the FTA terminal strips.
- Electrostatic Discharge (ESD) Protection: Sensitive termination networks require standard static controls. Always wear a grounded ESD wrist strap when working on or replacing the FTA board.
- Cable Strain Relief & Latching: Ensure multi-way connector cables linking the T8850 FTA to the Trusted I/O processor chassis are fully seated and locked with retaining latches to avoid signal degradation from panel vibration.
- Fuse Verification: If a specific output channel loses power, inspect onboard channel protection fuses/resistors for opens before replacing the entire assembly.
