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CHAPTER 3. DIGITAL I/O PROGRAMMING
On the PCL-725 card, 8 digital input channels and 8 relay output channels are
provided. Two I/O port addresses (started from BASE +0) are reserved for
accessing these channels.
The two addresses are allocated as :
BASE +0 D/O channel 0 - 7
BASE +1 D/I channel 0 - 7
A read operation on BASE+1 will read in the value (8 bits) of the 8
corresponding digital input channels.
To access these channels in BASIC, use the statement:
VALUE = INP(BASE+1)
A write operation on BASE +0 will set the desired status (1 =ON, 0 = OFF) on
the 8 corresponding relay output channels. To program these channels in
BASIC, use the following statement :
OUT BASE,XYZ
Where XYZ should be a number between 0 and 255. The status of the relay
outputs can be monitored by reading back the BASE+0 byte as shown below:
STATUS = INP(BASE)
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