PoE-modules - analog and digital - modules with power over ethernet

Ethernet modules analog and digital with power supply via PoE from Messcomp®

What is Power over Ethernet - PoE?

With Power-over-Ethernet modules, the modules can be powered via the Ethernet interface. With this method, the modules are supplied with power via the 8-pin Ethernet cable. The main advantage of Power-over-Ethernet (PoE) is that you can save on cables for the power supply. The power supply does not have to be supplied via an additional power supply unit via a power supply cable. It is sufficient to use a PoE-capable switch or an injector at a central location in the network distributor, which feeds the additional power into the data lines. This saves some of the installation costs and, when using an uninterruptible power supply, significantly increases reliability.

What is galvanic isolation?

The term galvanic isolation or potential separation refers to the avoidance of cables between two circuits. The exchange of signals between the two circuits takes place via electrically non-conductive coupling elements. Potential separation is used in the PoE-EXDUL modules mainly to separate the channels from each other and to protect the module with its Ethernet interface and to avoid interference (current loops, etc.).

Ethernet modules with galvanically isolated inputs/outputs

The PoE-EXDUL® Ethernet modules from Messcomp® with galvanic isolation are suitable for all applications from laboratory operation to harsh industrial environments. The isolation between the input signals and the Ethernet module is ensured in these modules by optocouplers and relays in various designs. By using various combinations of optocouplers and relays and the number of channels in the EXDUL® Ethernet modules, you can implement your control system cost-effectively.

Advantages and disadvantages of galvanic isolation via optocouplers

The greatest advantages of optocouplers are the short switching times and the lack of mechanical wear. This allows for significantly higher switching frequencies and a higher number of switching cycles than relays. In addition, optocouplers have only a low coupling capacitance between the inputs and outputs and do not cause interference from magnetic fields. The main disadvantages of optocouplers are the voltage drop in the output circuit, which causes a certain power loss and thus heating, and the sensitivity to overload and interference pulses.

Advantages and disadvantages of potential separation via relays

The low contact resistance and the low capacitance of the switching path speak in favor of galvanic isolation using relays. In addition, the relays can handle higher switch-on power, overvoltage and can be overloaded to a higher degree than the semiconductor variant. The disadvantages include the significantly longer response times and release times of the relays as well as wear and tear on the mechanics and contacts.

Was ist ein Analog-Digital-Wandler?

Der Begriff A/D-Wandler steht für ein Bauelement zur Umsetzung von analogen Eingangssignalen in einen digitalen Datenstrom, der vom Computer verarbeitet werden kann. Es gibt verschiedene Umsetzungsverfahren welche sich hauptsächlich in Geschwindigkeit, Genauigkeit und Rauschunempfindlichkeit unterscheiden. Deshalb werden z.B. bei der Temperaturmessung und der schnellen Signalabtastung verschiedene Wandlungsverfahren verwendet. Der A/D-Wandler ist die Grundvoraussetzung in der Messtechnik damit der Computer die analogen Eingangssignale verschiedenster Sensoren verarbeiten kann.

What is an analog-digital converter?

The term D/A converter refers to a component that converts the computer's digital data into an analog signal. This analog output signal can then be used to control a speed controller or other components with a voltage input.

Wat is an Pt100 sensor?

Pt100 is a platinum measuring resistor for temperature measurement. The resistance of platinum, which changes with temperature, is used to measure temperature. This resistance thermometer with the Pt100 has found widespread use and is standardized in EN 60751. The resistance characteristic is not linear and must therefore be adjusted using an electronic circuit or software.

Transmitter for PT100 und PT1000

A transmitter is a converter. As a PT100 or PT1000 transmitter, it converts the signal of the connected PT100 or PT1000 temperature sensor into a digital value for a defined temperature range. This value is linearized by the processor of the EXDUL module and converted into a temperature value in °C. It also compensates for the line resistance to the temperature sensor recorded by the three-wire connection circuit. The EXDUL-592PoE measurement technology module has three of these transmitters integrated, and the EXDUL-593PoE has six.

PoE Ethernet measurement modules with analog inputs and outputs for measuring voltage and temperature

The EXDUL® PoE modules with Power-over-Ethernet from Messcomp® with up to eight analog inputs and eight analog outputs are ideal for use in both the laboratory and in industrial control. The analog inputs have the input voltage ranges commonly used in professional control technology from +/- 0.63 volts to +/- 10.2 volts and sampling rates of up to 100 kHz. The analog outputs deliver a current of 5 mA at a voltage range of up to +/- 10.2 volts. These Ethernet modules usually have one or more optocoupler inputs or outputs available for switching purposes. The EXDUL-592PoE is a special measuring module for sensors. It has four voltage inputs and two current inputs. It also has three inputs for temperature measurement for the direct connection of PT100 temperature sensors.