The D100AU30 is an expansion cable accessory, which was initially designed and manufactured by Cutler Hammer. Nowadays this accessory is distributed by the Eaton Corporation under the Cutler Hammer product line. The Cutler-Hammer D100AU30 expansion cable has a flat shape and a length of 30 centimeters. This accessory was designed specifically to be used with PLC equipment, allowing the different parts of the process to be connected to each other. Longer cables are not recommended since there could be interference; instead, using short cables allows the units to receive high-quality signal and thus work properly. Regular cables cannot be used in industrial processes that require a high-speed data transmission, due to the lack of appropriate properties in a regular cable; for this reason, the D100AU30 type of expansion cable is used. The main function of the Cutler-Hammer D100AU30 expansion cable is to connect units and allow them to share signals, so that data may be transmitted in an efficient way. These cables are widely used in the electrical and power management fields, as well as within the process automatization field.

Some of the units that can be connected with this expansion cable include control circuit devices, digital and analog I/O modules, controllers, variable speed starters, gateways, stack lights, and alarms, among others. Using the Cutler Hammer D100AU30 expansion cable can reduce engineering design time, labor assembly time, commissioning time, and the amount of time spent on quality assurance revisions and monitoring. When this cable is used with PLC and I/O systems it can save time and money.