A wide range of control cabinets are used on the factory floor in the automation industry. Frequent monitoring and control of process parameters requires signal conversion and/or isolation before connection to PLC analog input channels.
The automation industry needs to deal with process monitoring and control, for example in factory floor manufacturing applications. In modern factories, a wide range of process parameters need to be monitored, which requires a higher number of signal conditioners. All factories need to be more efficient and save costs by saving space and conserving energy wherever possible.
Typically located on the factory floor, control cabinets house a wide range of equipment, usually mounted on a DIN rail found inside the cabinet. The equipment housed typically includes PLCs, power supplies and signal conditioners, in addition to DIN rail interconnecting blocks.
With an increasing trend towards cost savings in factory automation, there is a clear need for space saving. Larger signal conditioners require more space inside the control cabinet, and so generate increased costs in cabinet size. In addition, larger cabinets take up more space on the factory floor.
Three Major Challenges
The requirement for signal conversion comes in a wide range of input and output (I/O) possibilities. Signal conditioners with fixed input and output ranges need a different module for combination of input/output.
If a signal conditioner is non-isolated, ground loops or other spurious voltages will not be effectively blocked from passing through the signal conditioner. This has the potential to damage sensitive downstream equipment, for example, the PLC or data acquisition system.
If a signal conditioner has a higher power requirement, larger power supplies have to be mounted on the DIN rail inside the control cabinet. This can take up more space and generate excessive heat.
If older signal conditioners are used, they are usually fairly large, up to 25 mm (1") in width and air gaps in between modules are required in order to leave space for heat transfer for cooling. As a result, 50 units can take up as much as 1.25 m (4.1') or more of DIN rail space, which can lead to one or two rows of signal conditioners depending on the size of the control cabinet.
If galvanic isolation of process signals to PLC equipment or SCADA systems is required, the DRSL-U isolated universal input DIN rail signal conditioner provides a competitive choice in terms of both price and technology.
Isolated DIN Rail Signal Conditioner with Universal Input
The DRSL-U accepts a wide range of inputs, including RTD, thermocouple, potentiometer, linear resistance, current or voltage input and converts these signals to linear current or voltage output. The unit offers isolation between supply, input and output, protects control systems from transients and noise and provides surge suppression. The DRSL-U can also be used to measure floating signals and can provide electrical isolation and eliminate ground loops.
The DRSL-U has a slimline housing that is only 6 mm (0.24") wide, making it space efficient. As many as 50 units can be mounted on a DIN rail in the control panel, occupying as little as 30 cm (11.8") on the rail. The low power design of the DRSL-U means that using the typical 24 Vdc power, 50 units require only 40 W. DRSL-U signal conditioners can be stacked either horizontally or vertically and no air gap in between modules is required, saving additional space.
The DRSL-U is easy to configure using the DRSL-DISPLAY programming interface alongside the DRSL-ADAPTOR configuration adaptor. The DRSL-DISPLAY has a 4-line LCD display, which is able to provide scrolling help text in 7 languages (English, German, Spanish, French, Italian, Swedish and Danish), and can guide users through all the configuration steps. The DRSL-U is designed with electronic hardware switches, meaning that the device does not need to be opened in order to set any internal DIP-switches.
This information has been sourced, reviewed and adapted from materials provided by OMEGA Engineering Ltd.
For more information on this source, please visit OMEGA Engineering Ltd.