The 1775-KA is a Communication Adapter Module that manufactured by Allen-Bradley. It belongs to the 1775 series of PLC 3 modules and works with other series by connecting them to an Allen Bradley local area Network. It weighs about 4 pounds and 1 ounce (or 1.81 kilograms) and has dimensions of 16 x 2 x 11 inches (41 x 5 x 28 centimeters). The 1775-KA requires 115 Volts at 60 Hertz, or 230 Volts at 50 Hertz and 3.5 Watts to operate. Its operating temperature range extends from 0 up to 60 degrees Celsius, while it can be stored at temperatures ranging from -40 to 85 degrees Celsius.

The 1775-KA features a pass/fail self-test diagnostic indicator, which tests for its functional capabilities upon startup. At the front of the 1775-KA module are two ports; one of these ports is for communication with the RS–232–C, while the other port is for Data Highway connection. Each of these ports has indicators for communication and both of them help the 1775-KA to perform its vital function of interfacing the PLC-3 processor with an RS–232–C and a data Highway. A thumbwheel switch is also present at the front of the 1775-KA module, which is used to select the required identification number. As a member of the PLC 3 module series, the 1775-KA has multiple configurations and expansion options, which the user can select.The 1775-KA is adapted to sending and receiving different types of command, protected, unprotected, privileged, and non-privileged. Some of the message command procedures with which the 1775-A module works with are the ASSIGNMENT command (which is the most basic), the CREATE command, the EXIT command, the GOTO command, and the IF and STOP commands. Each of these commands has specific functions within the 1775-KA adapter module, which would be carried out when programmed.