User Manual

Connecting Sensors and Actuators to Input/Outputs
48 Advanced Digital Motor Controller User Manual V2.0, July 8, 2019
Important Warning
Overvoltage spikes induced by switching inductive loads, such as solenoids or re-
lays, will destroy the transistor unless a protection diode is used.
Connecting Switches or Devices to Inputs shared with Outputs
On HDCxxxx and HBLxxxx controllers, Digital inputs DIN12 to DIN19 share the connector pins
with digital outputs DOUT1 to DOUT8. When the digital outputs are in the Off state, these out-
puts can be used as inputs to read the presence or absence of a voltage at these pins.
Input
Buf
fer
+5V Out
GND
Output
Driver
1K
to
10
K
50K
DIN12 to DIN19
(DOUT1 to DOUT7)
FIGURE 3-3. Switch wiring to inputs shared with outputs
For better noise immunity, an external pull up resistor should be installed even though one
is already present inside the controller.
Important Warning
Do not activate an output when it is used as input. If the input is connected directly
to a positive voltage when the output is activated, a short circuit will occur. Always
pull the input up via a resistor.
Connecting Switches or Devices to direct Digital Inputs
The controller Digital Inputs are high impedance lines with a pull down resistor built into
the controller. Therefore it will report an Off state if unconnected, A simple switch as
shown in Figure 3-4 can be used to activate it. When a pull up switch is used, for better
noise immunity, an external pull down resistor should be installed even though one is al-
ready present inside the controller.
33kOhm
1K
to
10K
5V Out
20kOhm
DIN
Ground
FIGURE 3-4. Pull up (Active High) switch wirings to DIN pins