Voltage Input

Voltage Output

Current Input

Temperature

Digital I/O

Counter & Timer

Cases

Network

Accessories

Current Input

In most industrial and scientific process-monitoring applications an effort is made to use a physical principle so that the physical properties of a process result in a corresponding electric output signal which can be handled much more easily. Depending on the existing interfaces, the environment and other components, usually a voltage or current signal is desired.

An industrial 20 mA transducer generates an output current which is proportional to the measurement value and is commonly supplied by an external power supply. The device  CI01 features an internal power supply and high precision analog to digital converters. Up to two current transducers can be read out simultaneously.

Current Loops

Due to the low impedance, the transmission of the signal by the use of a current loop decreases the sensitivity to electro-magnetic interference which results in an improved signal-to-noise ratio. Therefore the length of the transmission line can be increased to several hundred meters or more. The 4 mA output signal represents the zero-level whereas 20 mA output is representing the full-scale output value. When the transmission line is broken or malfunctioning, the currents drops below 4 mA which can be detected by the receiver at the other end of the line.