The 1785-L40E is a PLC-5/40E EtherNet/IP Programmable Controller manufactured by Allen Bradley/Rockwell Automation as part of the PLC 5 product line. It comes with a 48-kilobyte word user memory, Allen Bradley EtherNet Enabled programmable controller, with 2048 input and output maximum capacity used for control processes of the connected field devices. This controller is installed on the furthest slot of 1771 I/O chassis and draws a backplane current of 3.6 amperes at 5 volts DC with a maximum operational thermal dissipation of 65.00 BTU per hour. It also supports the Allen Bradley 1770-XYC battery module and uses the 1785-M100, 1785-ME16, 1785-ME32, or 1785-ME64, lithium battery-backup memory modules. Allen Bradley 1785-L40E controller is compatible with the 32-point, 16-point, 8-point, and the 1771 intelligent input and output modules. Additionally, the controller provides the user with a maximum selectable input and output scan time of only 0.5 milliseconds for the extended-local I/O adapter, as well as input and output scan time of 10 milliseconds for remote I/O rack at 57.6 kilobytes per second, with a scan time of 3 milliseconds for the remote I/O rack at 230.4 kilobytes per second. It features a processor user memory of 48 Kilobytes words SRAM, and supports a maximum of 16 input and output racks (0 – 15), along with a maximum of 61 input and output chassis links. The 1785-L40E communicates to the input and output hardware through 3 different modes. These are the 2-slot mode that addresses any selection of 8-point modules as well as a pair of 16-point modules, with 1-slot mode that addresses any mix of 8 and 16-point modules. It also has 1 pair of 32-point input and output modules, with a half-slot mode that addresses a combination of 8-point, 16-point, and 32-point modules.

The 1785-L40E Ethernet PLC-5 programmable controller from Allen Bradley / Rockwell Automation has a power consumption rating of 3.6 amperes maximum at a voltage of 5 volts direct current (DC). This product also has a power dissipation rating of 18.9 watts maximum. The isolation rating of this programmable controller is 50 volts basic insulation between the communication ports, as well as between the communication ports and the backplane. The isolation of this controller was tested to withstand 500 volts root mean square (rms) for a duration of 60 seconds. When operating the Allen Bradley 1785-L40E Ethernet PLC-5 programmable controller, it is important for the temperature of the environment surrounding the product to range from 0 degrees Celsius to 60 degrees Celsius, or the equivalent temperature range of 32 degrees Fahrenheit to 140 degrees Fahrenheit. When this product is not being operated, or needs to be stored, the temperature of the surrounding environment should range from -40 degrees Celsius to 85 degrees Celsius, or -40 degrees Fahrenheit to 185 degrees Fahrenheit. The relative humidity levels suitable for this device range from five percent (5%) to ninety-five percent (95%) non-condensing. The Allen Bradley 1785-L40E can withstand a vibration rated at 2 G at a frequency range of 10 to 500 hertz. This programmable controller can also withstand an operating shock rated up to 30 G, as well as a non-operating shock rated up to 50 G. The Allen Bradley 1785-L40E programmable controller does not have an enclosure. Therefore, this product is considered to be an open-style device. This programmable controller has an approximate weight of 1.39 kilograms, or the equivalent of 3 pounds and 1 ounce.