This product range from PR electronics is used to measure e.g. flow in the food industry and frequency on offshore oilrigs. This is the range of frequency and pulse modules: 2255 and 2288 These two modules for DIN rail mounting with 11-pole socket constitute the 2200-series. The front key configurable 2255 is designed for f/I – f/f conversion. The functional module 2288 is specifically designed for pulse inversion and can be programmed via dipswitches. Additionally, both modules are suitable for pulse stretching, so that the signal can be adapted to the PLC. 4000-series The 4222 is a DIN rail mounted I/f converter which is programmed by way of the detachable programming interface 4501. The 4501 guides the user through all the configuration steps via scrolling help texts.