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For GRD-3G/4GA/4GM |
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MQ devices match XF power supply and I/O specs |
Below you will find the minimum and maximum admissible values of digital inputs and outputs as well as analog voltage and current inputs, and also GRD consumption and power supply.
Parameter |
Condition |
Minimum |
Maximum |
Units |
Input voltage |
|
10 |
30 |
Vdc |
Average consumption |
GRD at 24 Vdc |
|
100 |
mA |
Maximum consumption |
GRD at 24 Vdc |
|
1 |
A |
To activate the digital inputs a continuous voltage must be applied externally. This source of power has to share the GND terminal with the power supply of the equipment. If necessary the same power supply that feeds the GRD can be used. The input is of a Sinking type. It accepts sensor or PNP Sourcing type devices.
GRD3621-XF-3G/4GA/4GM and GRD3625-XF-3G/4GA/4GM
Parameter |
Minimum |
Maximum |
Units |
Activated input |
7 |
50 |
Vdc |
Input impedance |
280 |
|
KΩ |
Count frequency |
|
45 |
Hz |
| GRD3534-XF-3G (A and B) | GRD3534-XF-3G/4GA/4GM (C version or higher) | ||||||||||||||||||||||||||||||||
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We now show two examples of how to connect an input, directly from the same source feeding the equipment and from an external source where we can clearly see that they must share the common Terminal.
Digital outputs are of the open collector type. The load to be connected must be fed with an external power supply and they have to share the GND Terminal with the equipment power supply. If necessary, the same power supply used to feed the equipment can be used.
The output type is NPN Sourcing type (Open collector).
GRD3621-XF-3G/4GA/4GM / GRD3625-XF-3G/4GA/4GM
Parameter |
Maximum |
Units |
Withstand voltage |
50 |
Vdc |
Current |
200 |
mA |
| GRD3534-XF-3G/4GA/4GM (A and B) | GRD3534-XF-3G/4GA/4GM (C version or higher) | ||||||||||||||||||
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When the digital output is used to actuate a relay coil a protection diode must be added to the connection to avoid damage to the output of the equipment. This must be connected in reverse, that is the anode to the output terminal of the equipment and the cathode to the positive terminal feeding the relay. The relay must be fed using an external power supply, sharing the GND terminal with the power supply of the equipment, or if necessary the same power supply feeding the GRD can be used.
The following graph shows how to connect a relay to a digital output of the equipment.
Analog inputs refer to the GND Terminal of the equipment, consequently, the power supply used to feed the sensor must share the GND terminal with the equipment.
Parameter |
Value |
Units |
Full scale |
10 / 1 |
Vdc |
Precision |
1 / 0.1 |
mV |
Input impedance |
11.4 |
KΩ |
The following two examples show how to connect and analog voltage input for a single power supply or for independent power supplies.
Parameter |
Value |
Units |
Full scale |
20 |
mA |
Precision |
10 / 1 |
uA |
Shunt resistance |
100 |
Ω |
The following two examples show the connection of a 4 – 20 mA sensor sharing the power supply with the equipment for passive sensors or for active sensors with independent power supply.
PT100 inputs (GRD-3621-XF-3G/4GA/4GM only)
Parameter
Value
Units
Full scale
-199 to 849
ºC
Precision
0.1
ºC
In the following diagrams you can see how to connect 2 and 3 wires PT100 sensors.
2022-03-17
