The Allen-Bradley 1771-WF, also cataloged as the 1771-WF Wiring Arm, operates as a dedicated hardware component for field signal termination and I/O module interface wiring within Allen-Bradley PLC-5 chassis platforms.
Hardware Specifications
Parameter
Specification
Model
1771-WF
Brand
Allen-Bradley
Origin
USA
Weight
0.56 lbs (0.26 kg)
Dimensions
4.5 x 12.4 x 6.3 inches
Operating Temp
0 to 60 deg C (32 to 140 deg F)
Power Consumption
Passive Component (0 W)
Module Type
Wiring Arm
Max I/O Count
8 I/O Points
Number of Terminals
18 Terminals
Contact Plating
Gold Plating
Screw Torque
7 to 9 lb-in
Required External Power
None
Conformal Coating
Yes
Typical AC Signal Delay (Off)
29 (+/- 8) ms
Typical DC Signal Delay (Off)
30 (+/- 7) ms
Firmware Flash Compatibility & Backplane Bus Execution
The 1771-WF provides physical signal path routing between field wiring and 1771 I/O modules, establishing direct connections through gold-plated contacts to ensure minimal interface resistance. Conformal coating on internal structures protects against corrosive ambient atmosphere exposure. Operating as a passive mechanical arm, the unit maintains direct bus pin alignment with backplane connectors without imposing backplane bus communication velocity overhead or requiring firmware flash compatibility updates.
Frequently Asked Questions
Q: Does the 1771-WF field wiring arm require an external power supply to process signals?
A: No, the 1771-WF is a passive wiring interface arm that operates without external power inputs or backplane current draw.
Q: What torque setting should be applied when securing field conductors to the 1771-WF terminal screws?
A: Terminal screws on the 1771-WF should be tightened to a torque specification of 7 to 9 lb-in.
Field Installation Guidelines
Chassis Mount: Pivot the bottom notch of the 1771-WF wiring arm onto the lower pivot bar of the 1771 Universal I/O chassis slot.
Terminal Wiring: Strip conductor ends and clamp them under individual terminal screws using a torque of 7 to 9 lb-in. Ensure low contact resistance across all 18 gold-plated terminals.
Module Engagement: Swing the arm upward against the front face of the installed 1771 I/O module until the locking latch catches securely, establishing electrical contact.
Shield Wire Grounding: Route field wire shields to dedicated cabinet ground bars to prevent electromagnetic noise coupling across analog or low-voltage control loops.
Strain Relief: Secure the incoming wire harness to the lower cable tie anchor to eliminate mechanical tension on individual terminal screws.
