KEY-TW, TSW, and TWTD are part of Idec Corporation’s family of programmable logic controllers (PLCs). KEY-TW is a microcontroller-based cost-effective solution for controlling small machines or systems, whereas TSW and TWTD are more advanced models that feature high-speed controllers to handle complex, high-speed machine operations. KEY-TW units are capable of communicating with a supervisory computer, such as a PC, via an RS232 or Ethernet connection, while TSW and TWTD units feature Ethernet connection with support for adding I/O peripherals. All three of these units are designed to offer users more flexibility and increased functionality, while at the same time providing easier programming and operation.