Schematic

Serial (RS232/USB) Operation
152 Advanced Digital Motor Controller User Manual V1.8 August 28, 2017
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TX Data
RX Data
Data Out
Data In
GNDGND
DB9 Female DB9 Male
FIGURE 14-3. RS232 extension cable/connector wiring diagram
Connecting to Arduino and other TTL Serial Microcomputers
Aduino and similar microcomputers have a TTL serial port while Roboteq controllers have
a full RS232 serial interface. RS232 has the following differences from TTL serial:
RS232 TTL Serial
Voltage Levels +10V/-10V 0-3V
Logic level Inverted Non-Inverted
A TTL to RS232 adapter must be therefore be used to convert to the Arduino serial inter-
face. Newer Roboteq controller allow the RS232 signal to be non-inverted. Interfacing to
Arduino or other TTL Serial interface can therefore be done with just a resistors, and 2
optional diodes as shown in the diagram below:
GND
Arduino or MCU with TTL Serial
5VOut
2 x optional shottky diodes
min 100mA, 20V
Use 1N5819 or similar
RxD
RxD
4.7K
TxD
TxD
GND
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5
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FIGURE 14-4. Simplified TTL to RS232 connection
The data sent from the TTL serial port are 0-3V and can be directly connected to the con-
troller’s RS232 input where it will be captured as valid 0-1 levels.