Parker Vansco VMM1210 - Page 21

User Guide 11
Inputs
Programmable Digital Input Specifications
Item
MIN
NOM
MAX
UNIT
Input voltage range
0
-
32
V
Overvoltage (5 minutes)
-
-
36
V
Active low pull-up resistance
2.9
3.1
3.3
kΩ
Active high pull-down resistance
1.0
1.1
1.2
kΩ
Capacitance at pin
-
0.01
-
µF
Active low - inactive to active threshold
0.9
-
2.05
V
Active low - active to inactive threshold
2.25
-
3.15
V
Active high - active to inactive threshold
0.9
-
2.05
V
Active high - inactive to active threshold
2.25
-
3.15
V
Minimum detectable pulse width
75
-
-
ms
3.1.1.2. Programmable Digital Input Configuration
Digital inputs are configured as active high or active low by using pull-up or pull-
down resistors internal to the module.
 When the input is configured as active high, an internal pull-down resistor is
used, and the input will be active when it is switched to battery voltage.
 When the input is configured as active low, an internal pull-up resistor is used,
and the input will be active when it is switched to ground.
3.1.1.3. Programmable Digital Input Installation Connections
A digital input is typically connected to a switch that is either open or closed.
 When the switch is open, the pull-up or pull-down resistor will ensure that 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 either battery voltage or
ground, which will be interpreted by the VMM1210 as active.
Active-high input
The active-high output must be connected to battery power to ensure that there is
a battery connection when the state of the input changes.