Purchase now 1786-TPR to ensure the highest signal integrity and spatial efficiency in your industrial ControlNet infrastructure. The Allen-Bradley 1786-TPR is a precision-engineered, right-angle coaxial tap designed specifically for the ControlNet physical layer. This non-powered, passive device provides a critical connection point between the RG-6 coaxial trunk cable and a specific network node, such as a PLC, drive, or I/O adapter. The right-angle design is particularly valuable in space-constrained electrical cabinets, allowing for a 90-degree drop cable exit that prevents cable strain and maintains the minimum bend radius required for high-frequency data transmission. By utilizing this genuine OEM component, maintenance teams can minimize signal attenuation and avoid the intermittent «Media Fault» alarms that frequently plague poorly designed network topologies. The 1786-TPR is essential for ensuring that your 5 Mbps deterministic network remains robust against electromagnetic interference and mechanical stress.
What Is the 1786-TPR?
The 1786-TPR is a ControlNet media component that functions as the physical interface for a network node. It consists of a passive circuitry housed in a ruggedized casing with three BNC connectors: two for the trunk line (in and out) and one for the drop cable. The right-angle orientation of the drop cable port is the defining feature of this model, enabling cleaner cable management in shallow enclosures. Because ControlNet operates as a high-speed, 75-ohm impedance-matched system, the 1786-TPR is internally tuned to prevent signal reflections that could corrupt time-scheduled data packets. It is fully compatible with all standard ControlNet RG-6 trunk cables and ensures that the electrical transition from the backbone to the device is transparent to the network protocol.
Key Technical Specifications
- Part Number: 1786-TPR
- Manufacturer: Allen-Bradley / Rockwell Automation
- Network Type: ControlNet
- Connector Orientation: Right-angle (90 degree)
- Impedance: 75 Ohms (Matched)
- Cable Compatibility: RG-6 Quad-shielded Coaxial
- Data Rate: 5 Mbps
- Mounting: In-line or via universal mounting bracket
- Operating Temperature: -20 to +70 Celsius
Network Architecture and Redundancy
In a standard ControlNet setup, the 1786-TPR is used to create a bus topology. For high-availability systems, the 1786-TPR is often deployed in pairs to support Redundant Media (Trunk A and Trunk B). This ensures that if one trunk cable is severed, the 1786-TPR on the secondary line maintains the communication link to the PLC. The passive nature of the tap means it does not require external power, making it a highly reliable, «set-and-forget» component of the industrial physical layer.
Expert Tips
When installing the 1786-TPR, the most critical expert tip is to ensure that every unused trunk port on the final tap of a segment is terminated with a 1786-XT 75-ohm terminator. Leaving a port open on the 1786-TPR creates a signal reflection that will bounce back through the network backbone, leading to cyclic redundancy check (CRC) errors and potentially dropping nodes. Additionally, always use a torque-limiting BNC wrench to ensure the connectors are seated firmly without over-tightening, which can damage the internal gold-plated pins of the tap.
Frequently Asked Questions
Q: Can I use the 1786-TPR for an Ethernet connection?
A: No. While both use BNC connectors in some legacy forms, the 1786-TPR is specifically designed for 75-ohm ControlNet signaling. Standard Ethernet operates on different impedances and frequencies; using this tap for Ethernet will result in a total loss of signal.
Q: What is the maximum length of the drop cable connected to the 1786-TPR?
A: Rockwell Automation guidelines specify that the total length of the drop cable from the 1786-TPR to the device should not exceed 1 meter (3.3 feet) to maintain signal timing and integrity.
Do you need more references from this brand? Explore our full catalog of Allen-Bradley here: https://atlantechdrives.com/manufacturers/allen-bradley/
