Product Overview
The Allen-Bradley 1785-L20C15 is a ControlNet PLC-5 processor from Rockwell Automation, part of the PLC-5/20C series. This controller integrates local, extended, and remote I/O modules into an unified system, addressing diverse process control challenges. It features an integrated ControlNet phase 1.5 communication interface, enabling seamless integration into ControlNet networks.
Technical Specifications Breakdown
Key parameters for the 1785-L20C15 are listed below for quick reference:
| Feature | Specification |
|---|---|
| Module Type | ControlNet PLC-5 Processor |
| Processor | PLC-5/20C |
| Max User Memory Words | 16 Kilowords |
| Battery-Backed Static RAM | Yes |
| Max Total I/O Forcible | 512 (any mix) or 384 in + 384 out (complementary), Nonforcible 3200 |
| Max Analog I/O Forcible | 512 and Nonforcible 32000 |
| Max I/O Chassis Total | 77 |
| Max I/O Chassis Universal Remote | 12 |
| RS-232-C/422-A/423-A Ports | 1 |
| Control Coprocessor Expansion Port | Yes |
Industry Applications
For example, in automotive assembly lines, it coordinates multiple stations via ControlNet, ensuring precise timing. In material handling, it manages conveyor systems with remote I/O chassis, reducing wiring costs. Its ability to handle up to 512 forcible I/O points makes it suitable for complex batch processes.
Installation & Setup Guidance
When installing, mount the processor in a suitable chassis and connect the ControlNet BNC coax cables to the dedicated connectors. Use the front-panel key-switch to select RUN, PROG, or REM mode. For programming, connect via the DH+ port (channel 1A) or the RS-232-C port (channel 0). Ensure all devices on the same ControlNet network use the same phase (1.5) to avoid communication issues.
Maintenance & Reliability
Regularly inspect the lithium battery status via the BATT indicator (red when low). Replace the battery as needed to maintain backup of user memory. Keep the front panel clean and ensure adequate ventilation to manage heat dissipation (54 BTU per hour). Periodically check ControlNet cable connections for signal integrity.
Compatibility & Integration
The 1785-L20C15 integrates with ControlNet phase 1.5 networks, supporting redundant and non-redundant topologies. It communicates via DH+ on channels 1A and 1B, and remote I/O on channel 1B. It can be used with memory modules like 1785-ME16 for EEPROM backup. Multiple PLC-5 controllers can share the same ControlNet network for peer-to-peer data exchange.
Selection Guide & Purchasing Advice
When selecting this processor, verify its compatibility with your existing ControlNet infrastructure. AutoDCSTech offers the 1785-L20C15 as a reliable option for upgrading or maintaining PLC-5 systems. Please verify current lifecycle status and availability with AutoDCSTech before ordering.
Troubleshooting & Common Issues
If the PROC indicator shows red, check for processor faults via programming software. A low BATT indicator requires battery replacement. For communication issues, verify ControlNet cable connections and ensure all devices use the same network phase. If channel 1B is not communicating, confirm it is configured correctly as scanner or adapter.
Availability & Condition at AutoDCSTech
| Part Number | 1785-L20C15 |
|---|---|
| Availability | In Stock |
| Condition | New |
| Warranty | One Year |
| Origin | US |
