User manual

RS232-ADC16/24
8 Techincal Details
8.1 RS232 connector
Connection between host and RS232-
ADC16/24 device is realizied with a female
9-pin D-SUB connector. The pin layout is
consistent with the standard RS232 pin
mapping except -RI* which can either be
used to detect the device or as device's
alternative power supply pin.
Therefore -RI* is internally wired to VIN. As
result, if -RI* pin is connected to the host,
input voltage of device's power supply is
limited to 15V maximum due to the RS232
specification.
Note : Handshake currently is not used.
8.2 DSUB-25 connector
Analog sensors and digital peripherals are to
be wired at the male 25-pin D-SUB
connector. In addition to the eight digital IOs
D0 to D7 and the eight analog inputs A0 to
A7 this port provides a 3.3V power supply for
connected sensors and peripherals, so the
RS232-ADC16/24 device's voltage regulator
can be used to power these external
components eliminating the need of
additional voltage regulators.
Pins 6, 12 and 19 currently are not used but
reserved for possible extensions and should
not be connected.
Lines C2D and C2CK allow programming of
the used C8051F35x microcontroller.
AGND provides a seperated analog circuit.
Note : Power supply over VIN must not
exceed 15V if -RI* pin of RS232 connectior is
connected to a RS232 counterpart.
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