Parker Vansco VMM1210 - Page 29

User Guide 19
Inputs
The following table provides specifications for the multi-purpose inputs when
used as digital inputs:
Digital Input Specifications
Item
MIN
NOM
MAX
UNIT
Input voltage range
0
-
32
V
Overvoltage (5 minutes)
-
-
36
V
Active low pull-up resistance
3.1
3.3
3.5
kΩ
Capacitance at pin
-
0.01
-
µF
Active low - inactive to active threshold
1.23
-
-
V
Active low - active to inactive threshold
-
-
2.60
V
3.3.2.2. Digital Input Configuration
Digital inputs can only be programmed as active low, and they have a pull-up
resistance of 3.3 kΩ.
 Since the input is configured as active low, an internal pull-up resistor will be
used, and the input will be active when it is switched to ground.
3.3.2.3. Active-Low Digital Input Connections
An active-low digital input is typically connected to a switch that is either open or
closed.
 When the switch is open, the pull-up resistor will ensure no signal exists on
the input pin, which will be interpreted by the VMM1210 as inactive.
 When the switch is closed, the input is connected to ground, which will be
interpreted by the VMM1210 as active.
The active-low input must be connected to ground to ensure there is a ground
connection when the state of the input changes.