- Adds Ethernet communication to the PLC-5/20 controller while retaining serial and 1771 I/O operation
- Confirm the processor memory and supported rack and chassis capacity before selecting a replacement
- Preserve the Ethernet identity, communication routes, and ladder project before replacing the controller
1785-L20E adds an Ethernet path to the PLC-5/20 processor class while retaining the controller's serial and 1771 I/O responsibilities.
The official capacity table differentiates this model from larger L40E and L80E processors by memory, rack count, and total chassis allowance.
For maintenance, the network identity and communication routes are as important as the ladder application stored in the controller.
Availability, condition, price, and shipping time for 1785-L20E are confirmed during quotation.
Allen-Bradley 1785-L20E PLC-5/20E Ethernet Processor Manuals, Datasheets, Links
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
- The Ethernet channel uses the documented 15-pin AUI transceiver interface.
- TCP/IP communication supports controller access through the plant Ethernet network.
- IP addressing and connected transceiver hardware must be recorded before replacement.
- The official table lists 16K words of user memory for PLC-5/20E.
- The processor supports up to four documented I/O racks.
- Its chassis allocation is lower than the PLC-5/40E and PLC-5/80E families.
- Back up the PLC-5 application and communication-channel configuration.
- Preserve Ethernet addressing, message paths, and rack assignments.
- Validate program execution and every required network consumer after restart.
- PLC-5/20E control systems whose verified application fits the 16K-word memory and four-rack capacity
- 1771 architectures requiring Ethernet TCP/IP through the controller's 15-pin AUI interface
- Control applications combining Ethernet with serial, fixed DH+, and configurable DH+/Remote I/O communication