The Allen-Bradley 1747-L20C is a fixed style hardware controller. This module is part of the SLC 500 product family. It comes with embedded input and output channels, specifically Twelve (12) 24VDC sink inputs and Eight (8) AC/DC Relay outputs. Additionally, it has high-speed counter capability, allowing the controller to be used in industrial counting applications, typically required in the manufacturing industry.

The 1747-L20C requires a nominal 120 / 240VAC supply voltage to operate while the applicable input voltage range is 85-264 VAC with input frequency range of 47-63 Hz. This power supply has a built-in load-dependent hold-up time of 20 milliseconds to 700 milliseconds. It comes with an integrated fuse for line protection. The 1747-L20C is designed to withstand an inrush current rating of 30 Amperes, maximum.

The 1747-L20C has 1K Instruction Capacity program memory that is capacitor backed-up. The embedded processor has a typical scan time of 8 milliseconds/1K with bit execution speed of 4 microseconds. The modules memory backup options includes use of a EEPROM or UVPROM module. It has built-in LED indicators composed of POWER, PC RUN, CPU FAULT, FORCED I/O, and BATTERY LOW.

Like most controllers in the series, it supports a selectable 8K, high-speed counter capability. The 1747-L20C’s operational voltage is between 100 and 240V AC with 50VA of operational power and it provides 1.25A fuse protection at a 120-240V AC voltage range. The 1747-L20C has a 1K instruction program memory and offers users either the EEPROM or UVPROM backup option. Its maximum load-dependent delay time between scans is 20-700ms. It uses the base DH-485 communication port which acts only in the receiving capacity (slave) for communication and it displays the controller’s status through the LED indicators. The 1747-L20C offers the standard NEMA ICS 2-230 noise immunity rating and it is UL and CSA-certified. When operational, the 1747-L20C has a 30G shock rating at a 10-500Hz withstand. Its functional temperature range is between 0 and 60 0C at 5-95% non-condensing humidity.