Sensors / transmitters

Every automation system has a lot of analog measure points. One has to provide them to controllers. As you can see all kinds of different sensors and physical quantities transducers are the most important elements of the system. We have transducers, intended to convert the signal from the sensor (eg temperature) to a standard electrical signal used in automation (4-20 mA) and the same sensors in various designs. Sensors and transducers appliactions can be very different. Sometimes the same device can be used to measure the entirely different quantities. For example, rotary-pulse converter measure length, angle to indicate rotational and linear speed, etc. Similarly pressure sensor, depending on the configuration, may be used to measure liquid flow, liquid level in tanks, or even an indirect indication of strength. Completely separate family of devices are converters, They connect different standard of digital interfaces. Industrial automation devices usually use RS-485 as the primary transmission system, regardless of protocol implementation. By contrast, PC computers, mostly used as an HMI stations, typically have superior RS-232 or USB. These standards are not compatible with each other and require the use of appropriate converter.