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Functions Section 2-2
Terminals
2-1-1 Functions of Setting Pins
The setting pins are used to prohibit negative voltage output.
When negative voltage output is prohibited, 0 V is output from the voltage out-
put terminal if the Analog Output Unit has negative voltage output data.
Note 1. At the time of program debugging with an external device connected to the
Analog Output Unit, set the setting pins to prohibit negative voltage output
so that the wrong output will not damage the external device. Do not use
the Analog Output Unit to output negative voltage while the setting pins are
set to prohibit negative voltage output.
2. If an input circuit incorporating a pull-up resistor is connected to the Analog
Output Unit, set the setting pins to normal setting. If the setting pins are set
to prohibit negative voltage output, the Analog Output Unit will be influ-
enced by the synch current and no output will be ON properly.
3. Do not touch any internal components other than the setting pins.
2-2 Functions
2-2-1 Output Characteristics
The Analog Output Unit converts data from the CPU into voltage or current
and outputs the data to the voltage terminal or current terminal.
Voltage Output Data between 0000 and 07FF (hexadecimal) for output from the CPU are con-
verted into a voltage of 0 to 10 V and output.
Negative voltage is converted to 2’s complement with the MSB. Data between
F800 to FFFF (hexadecimal) for output from the CPU is converted into a volt-
age of –10 to 0V and output. If negative voltage output is prohibited, 0 V will
be output.
Bits 11 to 14 of output data have nothing to do with output voltage. For exam-
ple, 0 V is output for 0000 and 7800 (hexadecimal).
Terminal Usage
Output terminal 1 Connect analog output for output 1.
Output terminal 2 Connect analog output for output 2.
Setting pin Status
JT1 Word n: Normal setting
(factory set)
Word n: Negative voltage
output prohibited
JT2 Word n + 1: Normal setting
(factory set)
Word n + 1: Negative voltage
output prohibited
Left Right
123
Left Right
123
15
10 9 8 7 6 5 4 3 2 1 0
MSB LSB
These four bits have nothing to do with the output voltage.
MSB: Most significant bit
LSB: Least si
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