Siemens 3RS17 series of interface converters offer a variety of ways to convert or isolate analog signals in industrial applications. Sensors/actuators and controls generally have different power supply units, and therefore require electrical isolation in the signal circuit. This is either implemented in the control or is implemented using an interface converter. A signal must be converted into another signal if, for instance, a voltage signal needs to be transmitted over a long distance as a current signal – or if the output of a sensor and the input of a control system are not compatible with one another.

The 3RS17 series includes both 2-wire and 3-wire configurations. Footprints range from 6.2mm to 17.5mm and all modules are DIN rail mountable. Power to run the converter is either supplied by an external control voltage or in the case of a passive converter, is supplied by the analog signal itself.

3RS17 interface converters come in a wide variety of input and output configurations. For the most cost effective solution, specific input and output signal levels can be selected. For example, the 3RS1700-1DD00 has a fixed 0-10V input range and a 4-20mA output range. A common application for this device would be when an incoming analog input signal representing a level in a tank is 0-10V, but the micro PLC in the system only has 4-20mA analog inputs.

Other applications may call for Frequency outputs. In these cases, the signal is converted into a proportional frequency allowing analog signals to be processed with digital inputs. This is important if the control does not have provision for an analog input or if all of the analog inputs are already assigned. This will often occur in retrofit situations.

To cover a wide variety of applications with one device, Siemens offers the 3RS1706 universal input converter where 1 of 16 different input signal levels and 1 of 3 different output signal levels can be selected using two switches located on the side of the module. This will reduce the number of different devices that are selected, documented and stocked. It also offers a narrow 17.5mm width and will mount onto a standard 35mm DIN rail.

Siemens also offers a unique interface converter to the market. It combines the flexibility of a selectable input and output signal ranges, as well as the capability to bypass or override the input signal. The 3RS1725 has a selector switch to choose input and output signal levels similar to the universal converter. However, a bypass switch (Auto/Manual) and a potentiometer are also located on the top of these unique modules. When the switch is in the “Auto” position, the module converts the incoming signal level to the selected output signal level. When the bypass switch is in the “Manual” position, the input signal level is ignored and the output signal level is set using the potentiometer on top.

This design can provide two distinct application advantages:

Whatever the application, Siemens has the right interface converter to optimize your solution.