The Allen Bradley 1747-L511 is an SLC 5/01 Processor and part of the SLC 500 system. It is a small, easy-to-use processor with a wide range of applications including small process control, material handling, HVAC control, etc. It contains a PLC-5 processor-based advanced instruction set and can be stand-alone or distributed throughout for SCADA applications.


The 1747-L511 processor has total user memory of 1 K. It has up to 960 local digital I/O; its program scan time per keyword is 8 millisecond and it has a 2.6 millisecond I/O scan time. With a backplane current of 350 mA at 5 Volts DC and 105 mA at 24 Volts DC, it has a maximum of 3 local I/O chassis with a maximum of 30 module I/O slots in local I/O chassis. For communication, it uses DH-485 that can only send or receive messages but cannot initiate it. For programming, it supports RSLogix 500 software.


This module is not compatible with the 1746-BLM, 1746-BTM, 1746-MPM, 1746-HS, 1746-HSCE, 1746-QV, 1747-SN, 1747-SDN, or 1747-SCNR15 modules. It is intended for use in clean and dry industrial environments, with a 0-60 degree Celsius operating temperature and a 30 g operating shock. It has a battery backup for the 1747-L514 module and a capacitor backup for the 1747-L511 module, and includes red PC RUN, CPU FAULT, FORCED I/O and BATTERY LOW, LED status indicators for troubleshooting and diagnostics.


The 1747-L511 is the entry-level processor of the modular style hardware of SLC 500. This processor has the most basic features having a 1KB memory which makes it capable of handling up to 3940 IO signals. However, this module does not support implementation of Remote I/O topology. It may only be expanded of a maximum Three (3) SLC chassis of any type or a maximum 30 IO slots. This processor is UL listed to US and Canadian Safety Standards, CE compliant, and C-Tick marked.


This processor has memory back-up option of Electrically Erasable Programmable Read-Only Memory (EEPROM) which is basically a non-volatile memory, This non-volatile memory may be used to permanently store a the Programmable Logic Controller (PLC) program to prevent accidental deletion that is commonly caused by power surges and draining of the battery. It may also be configured to automatically load the user program each time a power cycle is initiated.


The integrated memory of this processor is Random Access Memory (RAM) that is maintained by a Lithium battery that can last up to Two (2) years. The battery charge is indicated by the Battery Low LED light which activates when the battery voltage is low. This battery is replaceable with 1747-BA however, do not replace the battery with the power removed. The processor must be actively powered when replacing otherwise, the user programs gets deleted.


This processor has other installed LED status indicators aside from the battery indicator. These indicators include Run, CPU Fault, and Forced I/O.