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Digital inputs
Instruction book, IQAN
Digital inputs
DIN that share pins with VIN
These digital inputs share pins with the module voltage inputs and have high
impedance characteristics. The preceding switch examples apply to these inputs.
DIN that share pins with CRET
These digital inputs share pins with the return pins of the proportional output channels,
e.g. CRET and PWMRET. These pins have an internal power clamping diode. If used
as inputs they must be connected in a way that prevents ’backending’, that is, supplying
power to the module from a source other than its power pin (+BAT).
Carefully read the following section for more information.
Connecting switches to the digital inputs
When connecting switches to the digital inputs, DIN, that share pins with CRET, extra
precautions should be taken.
WARNING
The DIN that share pins with the CRET positions of the proportional outputs have a
possibility of ’backending’ the IQAN module when using those pins as digital inputs.
The internal circuitry has power clamping diodes between CRET pins and the internal
power supply. This arrangement creates a risk of inadvertently supplying power to the
unit.
You can safely connect using +VREF for the supply, as shown in the preceding
"Connecting switches to the voltage inputs" example.
If you would like to preserve +VREF for sensors and joysticks, then there are two
additional methods:
1 The switches could be powered by one of the module’s DOUT pins.
EXAMPLE
Connect the supply of the switch to DOUT-X, and the signal to DIN-X , respectively.
Connecting a switch to DOUT-X and DIN-X.
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