The MicroLogix 1500 Programmable Logic Controllers are modularly designed with many components that can be changed to accommodate different application needs in terms of power type and processor capabilities, as well as several components that can be easily added to the devices to increase their scope. The basic elements used to configure these PLCs are base units that include 120 to 240 Volts AC or 24 Volts DC power supplies and 24 or 28 I/Os and processors. When the desired categories of these 2 types of components are selected and physically connected, the devices become fully functional and the items visible on the units are removable terminal blocks, interfaces to expansion modules (hidden behind the plate), groups of input and output status LEDs, device status LEDs, communication ports, batteries, mode switches, and trim potentiometers. Other parts that can be additionally mounted are a memory module, a replacement battery, and a data access tool. 

   The programming of the MicroLogix 1500 small programmable logic controllers is done by using the RSLogix 500 software when the controllers are connected to personal computers. The 1769 compact expansion I/O modules can be attached to the device to expand its I/O capabilities. The digital input circuit types on the MicroLogix 1500 devices are 24 Volts DC sink/source or 120 Volts AC inputs, and the digital output circuit types are relays or combinations of relays and FET transistors. To determine the current status of the PLCs, the users have 8 status LEDs which are the power, run, fault, force, battery-low, COMM 0, COMM 1, and DCOMM LEDs. The operating system of the units can be upgraded with a newer one in the controlFLASH upgrade kit.