Allen-Bradley 1771-ASB I/O Adapter Module | Remote I/O Adapter | PLC-5 Platform
Engineering Background
The Allen-Bradley 1771-ASB is a Remote I/O (RIO) Adapter Module designed for the 1771 I/O chassis within the PLC-5 control platform. It serves as the communication bridge between a remote I/O chassis and the PLC-5 processor (or compatible scanner), enabling distributed I/O architectures across large-scale industrial facilities. First introduced as part of Rockwell Automation’s legacy PLC-5 ecosystem, the 1771-ASB remains widely deployed in continuous-process, discrete manufacturing, and utilities environments where system replacement is cost-prohibitive.
Product Positioning
Konmask.com supplies the 1771-ASB as a verified surplus / refurbished unit targeting maintenance engineers, OEM integrators, and plant operations teams who require a drop-in replacement without full system migration. Each unit is sourced from controlled channels, inspected against Rockwell Automation’s published specifications, and dispatched with full traceability documentation.
Complete Technical Specifications
| Catalog Number | 1771-ASB |
| Manufacturer | Allen-Bradley / Rockwell Automation |
| Series | PLC-5 / 1771 I/O Platform |
| Module Type | Remote I/O Adapter (RIO Adapter) |
| Communication Protocol | Allen-Bradley Remote I/O (RIO) — 57.6 kbps / 115.2 kbps / 230.4 kbps |
| Chassis Compatibility | 1771 I/O Chassis (all slot widths) |
| Backplane Current Draw | 800 mA @ 5 VDC (typical) |
| Input Voltage | 5 VDC (via chassis backplane) |
| Operating Temperature | 0 °C to +60 °C (32 °F to 140 °F) |
| Storage Temperature | -40 °C to +85 °C |
| Relative Humidity | 5% to 95% non-condensing |
| Enclosure Rating | Open-style (requires enclosure installation) |
| Dimensions (H × W × D) | Single-slot 1771 module form factor |
| Weight | 900 g (approx.) |
| Agency Certifications | UL Listed, CE Marked (original production) |
| SKU / Part Number | 1771-ASB |
Proven Application Environments
- Automotive Assembly Lines — Distributed I/O control across multi-zone body-in-white and paint-shop conveyors
- Water & Wastewater Treatment — Remote pump station monitoring and valve control via RIO trunk cable
- Oil & Gas Processing — Wellhead and pipeline SCADA integration with PLC-5 host processors
- Food & Beverage Manufacturing — Hygienic-area remote I/O drops where local panel space is constrained
- Power Generation & Utilities — Turbine auxiliary control and switchgear monitoring in legacy DCS/PLC hybrid architectures
- Pulp & Paper Mills — Long-distance RIO trunk runs (up to 3,048 m / 10,000 ft) across large mill footprints
Engineering Advantages
- Drop-in Replacement — Identical form, fit, and function to original Rockwell production units; no firmware changes required on the host PLC-5
- Multi-Rate Baud Support — DIP-switch selectable baud rate (57.6 / 115.2 / 230.4 kbps) for flexible trunk configuration
- Rack Address Flexibility — Hardware-configurable rack and starting group address via onboard switches
- Passive Backplane Interface — No active logic on the backplane bus; minimises single-point failure risk in the chassis
- Long Cable Runs — Supports RIO trunk cable distances up to 3,048 m (10,000 ft) at 57.6 kbps
- Immediate Availability — Konmask maintains buffer stock to support emergency maintenance windows with same-day dispatch capability
System Architecture & Signal Flow
In a typical PLC-5 RIO architecture, the 1771-ASB occupies the leftmost slot (slot 0) of a remote 1771 chassis. The host PLC-5 scanner (e.g., 1785-KA5 or onboard scanner port) drives the RIO trunk cable — a shielded, twisted-pair Belden 9463 or equivalent — at the configured baud rate. The 1771-ASB decodes the RIO protocol, arbitrates backplane access, and maps I/O module data into the PLC-5’s I/O image table. Up to 32 remote racks (rack addresses 0–3, groups 0–7) can be addressed per scanner port, supporting large distributed architectures without additional network hardware.
Signal flow summary: PLC-5 Scanner → RIO Trunk Cable → 1771-ASB Adapter → 1771 Backplane → I/O Modules → Field Devices
Sourcing & Quality Verification
- All units sourced from OEM-authorized surplus channels or decommissioned plant equipment with documented service history
- Visual inspection: PCB, connector pins, label integrity, and housing condition verified against Rockwell Automation reference standards
- Functional bench test: backplane communication, DIP-switch continuity, and RIO link-up verified prior to dispatch
- Anti-static packaging with humidity indicator card; serialized shipping label for full traceability
- 30-day return window for DOA (Dead on Arrival) units with RMA process
Procurement Process
- Confirm Compatibility — Verify your host PLC-5 scanner firmware revision and chassis slot count against Rockwell Publication 1771-6.5.12
- Place Order — Add to cart and complete checkout at Konmask.com; purchase orders accepted for qualified B2B accounts
- Lead Time — In-stock units ship within 1–2 business days; ETA confirmation provided at order acknowledgement
- Customs & Export — HS Code 8537.10 declared; EXW Xiamen terms available; DDP options on request
- Technical Support — Pre-sale and post-sale engineering support via support@konmask.com or +0086 19859288691
Technical FAQ
Q: Is the 1771-ASB compatible with ControlLogix or CompactLogix?
A: No. The 1771-ASB is a PLC-5 / 1771 platform module. ControlLogix uses the 1756 chassis and EtherNet/IP or ControlNet — not RIO. For ControlLogix remote I/O bridging, consider the 1756-DHRIO or 1747-ASB (SLC 500 platform).
Q: Can I use the 1771-ASB as a scanner (master) rather than an adapter (slave)?
A: No. The 1771-ASB is an adapter-only device. It responds to a PLC-5 scanner; it cannot initiate RIO scans. Use the 1771-SN or 1785-KA5 for scanner functionality.
Q: What baud rate should I select?
A: Match the baud rate to your existing RIO trunk configuration. All adapters on the same trunk must operate at the same baud rate. Higher baud rates reduce scan time but limit maximum cable distance.
Q: Do you provide the Rockwell Automation installation manual?
A: Yes. Publication 1771-6.5.12 (1771-ASB Adapter Module Installation Instructions) is available upon request. Contact support@konmask.com.
Q: What is the warranty on surplus units?
A: Konmask offers a 30-day DOA guarantee. Extended warranty options (90-day, 1-year) are available for volume orders — contact us for terms.
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Original Source: https://Konmask.com
Contact: support@konmask.com | +0086 19859288691
