Phytec eGrabber-4plus, Hardware Manual

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Driver Software
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PHYTEC Meßtechnik GmbH 2004 L-608e_4
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Reading/Writing data via the option port (GPIO-Port)
12 I/O pins are available on the pin header row option port. These pins
can be controlled with the following three functions:
void Set_GPIO_Direction (WORD nDevNo, WORD nDirection);
void Set_GPIO_Data (WORD nDevNo, WORD nData);
WORD Get_GPIO_Data (WORD nDevNo);
nDirection: Direction control for GPIO-Port (0…4095), bit encoded
nData:
Data that should be sent out over the GPIO-Port
return value Get_GPIO_Data(): Data that is read by the GPIO-Port
The eGrabber-4plus has an option port with pins, which can be used
separately to read or write digital signals. With the following
functions the option port is controlled. You can define which pins will
work as input or output, set which output pins have low or high level
and determine what level is applied to the input pins.
With the help of the function Set_GPIO_Direction each pin of the
port can be configured as input or output. For this purpose the lower
12-bits of the parameter nDirection are evaluated. If a bit is set to 1,
the corresponding port is configured as output. A 0 results in a
configuration as input.
Caution:
Please pay attention, that a pin of the port is only switched to output,
when no external signal is applied to the pin. Otherwise it might
happen, that the pin circuitry is damaged.
All pins are configured to input when starting the computer. Please
ensure that the pins are high ohm and therefor the logic level is not
defined. Hardware precautions (i.e. pull-up resistors) must be taken in
order to determine the behavior of controlled components during the
start-up of the computer until the GPIO port has been configured.