Engineering Support

Description of the problem

How to connect a current sensor to a DSI-20mA adapter?

When it comes to a two-wire transducer, it is a bit confusing, as jumpers will be needed.

Description of the solution

Connection diagram explanation

The image below gives a brief explanation of how the connection diagram works.

We can clearly see that the connection diagram is divided into three parts:

• the Amplifier
• the Connections
• the Sensor

We concern ourselves mostly with the middle part- the Connector or cable- since this is usually the only part of connecting a Sensor to an Amplifier that we have to do on our own. We must always take care that we properly connect the sensor to the correct pins of the amplifier. 

As mentioned previously, we also have to be mindful of whether the lines are dotted or bold, which tells us whether or not this is a necessary connection.

Connection the sensor:

The adapter is made in such a way that most sensors can be connected to it. 

In some special cases, some additional wiring needs to be done. For example, when wiring a 2-wire sensor, a jumper (green) needs to be added to achieve proper excitation:

Behind the adapter, we created the missing bridge on the amplifier marked in the picture below:

Check the amplifier:

1. If the readings from the sensor are not correct the used amplifier must be checked. First, check the amplifier excitation to see if it is capable powering the sensor. 

2. Most of our amplifiers can make a short to the ground internally. But for those who lack this ability the short has to be made on the adapter (see the green wire):

The internal short

List of amplifiers that require the external short

Additional information

• DSI-Adapters Technical Reference Manual
• The difference between direct shunt and loop-powered shunt
• Amplifiers, Shunt, Single-ended options