Allen-Bradley 1785-L30B – PLC-5/30 Programmable Controller Processor | PLC-5 Platform
The Allen-Bradley 1785-L30B is a mid-range processor in Rockwell Automation’s legacy PLC-5 programmable controller family. Designed for demanding discrete and process control applications, it delivers a proven combination of I/O capacity, communication flexibility, and ladder-logic execution speed that has made it a backbone controller in heavy industry for decades. Konmask.com supplies verified, tested units with full traceability — supporting both active plant operations and long-term spare-parts strategies.
This processor is the preferred choice for engineers maintaining existing PLC-5 architectures or executing phased migration projects where a like-for-like replacement is required before a full ControlLogix upgrade.
Complete Technical Specifications
| Catalog Number | 1785-L30B |
| Platform | Allen-Bradley PLC-5 Series |
| Processor Type | PLC-5/30 |
| User Memory | 32K words (expandable) |
| Maximum I/O | 4,096 discrete I/O points |
| Maximum Remote I/O Racks | Up to 16 remote racks |
| Communication Ports | DH+ (Data Highway Plus), RS-232 (Channel 0) |
| DH+ Data Rate | 57.6 Kbps / 115.2 Kbps / 230.4 Kbps |
| Scan Time | ~1 ms/K words (typical) |
| Programming Software | RSLogix 5 (Rockwell Automation) |
| Backplane | 1771 I/O chassis compatible |
| Power Supply | Requires 1771-P4 or equivalent 1771-series power supply |
| 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 |
| Weight | Approx. 1.22 kg |
| Agency Certifications | UL, CSA, CE |
Proven Application Environments
The 1785-L30B has accumulated decades of field deployment across the following industries:
- Automotive Manufacturing — Body-in-white assembly lines, paint shop conveyors, and stamping press sequencing where deterministic scan times are non-negotiable.
- Oil & Gas Processing — Wellhead control panels, pipeline SCADA nodes, and compressor station automation requiring robust DH+ network integration.
- Pulp & Paper Mills — Coordinating multi-drive paper machine sections, winder controls, and stock preparation sequences.
- Water & Wastewater Treatment — Pump station control, chemical dosing, and SCADA-linked remote I/O architectures.
- Food & Beverage Processing — Batch sequencing, CIP (Clean-In-Place) control, and conveyor management in hygienic environments.
- Power Generation & Utilities — Turbine auxiliary systems, switchgear control, and substation automation panels.
- Mining & Minerals — Crusher sequencing, conveyor interlocking, and flotation cell control in high-vibration environments.
Engineering Advantages
- Proven Reliability — PLC-5 processors have an established MTBF record in harsh industrial environments; the 1785-L30B is no exception.
- DH+ Network Integration — Native DH+ port enables seamless peer-to-peer messaging and HMI connectivity without additional communication modules.
- Large I/O Capacity — 4,096 discrete I/O points accommodate complex machine architectures without requiring a processor upgrade.
- RSLogix 5 Compatibility — Full support for ladder logic, function block, and structured text programming via the industry-standard RSLogix 5 environment.
- 1771 Chassis Compatibility — Drop-in replacement for existing 1771-series installations; no chassis or wiring changes required.
- Long Service Life — Ideal for facilities committed to maintaining existing PLC-5 infrastructure through end-of-life or phased migration timelines.
System Architecture & Signal Flow
The 1785-L30B resides in slot 0 of a 1771-series I/O chassis and communicates with local and remote I/O modules via the 1771 backplane. The processor executes a continuous scan cycle: Input Image Update → Program Scan → Output Image Update. Remote I/O racks connect via the 1771-ASB Remote I/O Adapter over a shielded twisted-pair remote I/O cable (Belden 9463 or equivalent). HMI and programming terminals connect via the DH+ port (Channel 1A) using 1784-KTX or 1784-PCMK communication cards, or via RS-232 Channel 0 for DF1 protocol connections. Inter-processor messaging is supported through MSG instructions over DH+.
Sourcing & Quality Verification
- All units sourced from authorized distributors or directly from decommissioned OEM installations with documented service history.
- Each processor undergoes functional power-on testing and memory integrity verification prior to shipment.
- Firmware version is recorded and disclosed at time of quotation.
- Units are shipped in anti-static packaging with foam cushioning to prevent transit damage.
- Counterfeit-prevention inspection performed on all incoming stock per IEC 62239 guidelines.
Procurement Process
- Submit RFQ — Contact us via support@konmask.com or +0086 19859288691 with your required quantity and any firmware version preferences.
- Receive Quote — We respond within 24 hours with pricing, lead time, and available stock confirmation.
- Order Confirmation — Purchase order accepted; unit reserved and prepared for shipment.
- Quality Check & Dispatch — Final inspection completed; tracking number issued within 1–2 business days.
- Delivery & Support — Post-delivery technical support available for installation and commissioning queries.
Technical FAQ
Q: Is the 1785-L30B compatible with ControlLogix chassis?
A: No. The 1785-L30B is designed exclusively for the 1771-series I/O chassis. It is not compatible with ControlLogix (1756) or CompactLogix (1769) platforms.
Q: What programming software is required?
A: RSLogix 5 (version 7.x or later recommended) running on a Windows-compatible PC. A 1784-series communication card or USB-to-DH+ adapter is required for program upload/download.
Q: Can this processor communicate with ControlLogix systems?
A: Yes, via a 1756-DHRIO module installed in a ControlLogix chassis, enabling DH+ bridging between the two platforms.
Q: What is the difference between 1785-L30B and 1785-L30C?
A: The suffix letter denotes the firmware/hardware revision. The L30C is a later revision with minor enhancements; both are functionally equivalent for most applications. Confirm compatibility with your existing program before substitution.
Q: Do you provide a warranty?
A: Yes. Konmask.com provides a 90-day functional warranty on all tested units. Extended warranty options are available upon request.
Q: Can you supply multiple units for a plant-wide spare parts program?
A: Yes. Volume pricing is available. Contact us with your total quantity requirement for a tailored quotation.
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Original Source: https://Konmask.com
Contact: support@konmask.com | +0086 19859288691
