Keyence manufactures low-cost super-small plcs of kv series. They have all the advanced technical features one expects in a high performance plc. The kv series allows for 10-80 i/os expandable to a maximum of 128. Some of the features include fast scan time, fast interrupt time, 2 built-in high speed counters, multiple counters and timers, direct clock pulse output for stepper motor control. Up to 3000 steps can be written in the ladder program. It also includes a rs-232c port and 2 externally adjustable analogue timers that can be changed on-line. Kv-300 series super micro plcs also from keyence are said to be fastest, smallest, simplest and cost-effective with advanced i/o distribution system. All the modules can be connected to cpu using only a single twisted pair. No definite order to place terminal i/o modules. The maximum i/os are 1774 of which 20 are analogue type. Cpu uses a common address for all i/o modules in the network. Minimum scan time of 200 microsecs and with full 1774 i/o load, total i/o scan time is still only 500 microsecs. Kv-300 guarantees reliable high-speed control with its fast scan time and 0.15 microsecond instruction execution time. Kv plcs are easier to program than any other plc. The ibm compatible kv incrediware software allows for simulation of the plc, wherein the plc need not be connected to the pc. The keyboard is simulated as inputs, while the outputs are displayed on the monitor. On-screen timing displays, ladder monitoring and on-line help make programming easier. This saves many hours required for programming and debugging, hence increasing productivity.
