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emVIEW-7/RPI3
(
Hardware and Software Manual
)
•
Installation
©
Janz Tec AG
Rev. 1.0
3.2.7
Digital IO
Digital input (DI1-DI4) and output (DO1-DO4) ports are provided on the multi IO connector (refer to
table 7).
1
2
9
10
1 DO4
2 DO3
3 DO2
4 DO1
5 GND-IO
6 VIO (10..32 VDC)
7 DI4
8 DI3
9 DI2
10 DI1
table 7: Digital IO connector pins
CAUTION
The digital IO must be powered by a SELV power supply, that complies with the
requirements of a limited energy source (LPS) (By using an appropriate supply or an
external fuse).
The digital inputs and outputs are isolated from system power supply. Refer to figure 5 for detailed
schematic.
The digital input signals (DI1-DI4) refer to GND-IO and have an input impedance of about 5 k
Ω.
Switching level for
low
is
≤4V and
high
≥9V. The digital inputs do not require VIO to be present.
The digital outputs drive VIO power to the output pins (high side switch). The load must be connected
between the output pin and the return of the VIO power supply.
The output driver supports resistive and inductive loads.
NOTICE
When using inductive loads, the output driver has internal clamping to demagnetize the
load. This clamps the output pin to about 55 V below VIN. When using this feature, very
carefully evaluate that the demagnetization energy does not overheat the output driver.
Parameters to check are the switching frequency, the load current, the load inductance
and VIO voltage. Refer to the VN330SP datasheet for more information. If in doubt, add
external clamping circuits.
VIO
VN330SP
Polarity
Reversal
Protection
DO
Output GPIO
GND-IO
DI
Input GPIO
Load
figure 5: digital IO detailed schematic