Weidmuller WI-I/O-9-U2: Wireless Mesh I/O & Gateway User Manual V1.2.2 - Manual (Page 34)

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2.5.5 Analog Inputs
The WI-I/O 9-U2 provides two floating differential analog inputs and two grounded single-ended
analog inputs.
Analog Input 1 & 2 will automatically measure Current (0-20 mA) or Voltage (0-25V) depending
on what is connected to the input.
Analog input 3 & 4 must be configured to measure Current (0-20mA) or Voltage (0-5V) via the
DIP switches under the Side Access Configuration Panel (See Section 2.5.2 ).
An internal 24V Analog Loop Supply (ALS) provides power for any current loops with a
maximum current limit of 100mA.
The LEDs have an analog diagnostic function and will indicate the status of the input.
If the current is less than 3.5 mA the LED will be off and if greater than 20.5mA the LED will be
on. The LED will flicker with the duty cycle relative to the analog reading in this range.
(Note by default there is a 5 second delay on the input because of the Filter) Filter times
can be changed by accessing the Analog Input on the I/O configuration web page or
using the WI-Series Configuration software.
The LEDs beside AI1+, AI2+ flash according to current on these inputs. LEDs beside AI1- and
AI2- flash according to the voltage on the Analog inputs.
Differential Current Inputs (AIN 1 & 2 only)
Differential mode current inputs should be used when measuring a current loop, which cannot
be connected to earth or ground. This allows the input to be connected anywhere in the current
loop. Common mode voltage can be up to 27VDC.
The diagram below (Figure 17 – Differential Current Inputs) indicates how to connect Loop
powered or externally powered devices to the WI-I/O 9-U2 Differential Analog Inputs.
It should also be noted that the differential Inputs can also be used to connect single ended
current sinking or current sourcing devices. Figure 18
– Single Ended Current Inputs shows how
to connect to these types of devices.
Figure 17 – Differential Current Inputs Figure 18 – Single Ended Current Inputs
WI-IO 9-U2
WI-IO 9-U2