D105: Connecting the meters with a impulse output

Counters (flow meters) with impulse output

Two flow meters with a impulse output can be connected to one smart-MAC D105. It can be meters for water, gas, heat, fuel, milk, beer and many others.
Two types of impulse outputs must be distinguished:

  1. The meter with a impulse output of the type "Dry contact" (mechanical meters).
  2. The meter with a impulse output of the type “n-p” (electronic meters).

Two-wire circuit with "Dry contact"

Water meters, e.g., are often equipped with a impulse output of the "dry contact" type and have two wires (two contacts) for connection.
On the connection diagram of a water meter with a impulse output of the "dry contact" type the colors do not matter and are shown conditionally.

Two-wire circuit for connecting a impulse meter to smart-MAC D105.

Impulses calculated for a certain interval (minute / hour / day / month) are stored in parameters Ch1 and Ch2.
Parameters TCh1 and TCh2 are accumulative counters and are constantly increasing. To synchronize D105 data with the meter, set the initial values ​​for accumulative counters in the device settings, in the Current Data menu.

The initial values ​​of the accumulative counters are indicated in impulses.

In this case, you need to know the value of the impulse, because the values ​​in the parameters are stored in impulses, not in liters or m³. The impulse value is usually indicated on the meter or in its passport.

Widget settings on the Dashboard

Add a widget indicator, chart or table to the Dashboard.
Select your smart-MAC D105 device and the corresponding impulse input to which the meter is connected, Ch1 or Ch2.

In the "Arithmetic operation" section, select "multiply" by the value of the impulse.

An example of a regular water meter, where the impulse value is: 1 imp = 0.01 m³.

Three-wire circuit with "n-p" type

High precision meters are equipped with an “n-p” type impulse output and are connected in a three-wire circuit with separate power supply. If the power supply voltage of the flowmeter is + 5V, then it can be obtained to contact 6 (+ 5V) of the D105 device. Any other supply voltage to the flowmeter will require a separate power supply.
Connection diagram of a flowmeter with a impulse output of the "n-p" type:

  • connect the GND flowmeter black wire to contact 1: GND (Ground or -5V)
  • connect the red wire + 5V of the flowmeter to contact 6: + 5V
  • connect yellow wire the impulse of the flowmeter to contact 2 or 3: Ch1 ​​or Ch2

Three-wire circuit for connecting a flow meter to smart-MAC D105.

If the flowmeter requires a separate power supply of more than + 5V, then its common GND output must be combined with the common output of the D105 device, contact 1 (GND). In this case, contact 6 (+ 5V) remains unused.

General wiring diagram for flow meters with “n-p” type impulse output.

Three-wire circuit with "p-n" type

The meters with "p-n" impulse type cannot be directly connected to the smart-MAC D105.
To connect them, additional interfaces are required.

General wiring diagram for flow meters with “p-n” type impulse output.

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