
6. CONNECTION OF I/O UNITS TO
MACHINE INTERFACE
B–63323EN/03
260
The keyboard of this operator’s panel is a matrix composition. When three
or more keys are pushed, the bypass current cause unrelated key to be
available. This malfunction can be prevented with ladder program. One
example is shown as follows.
(Elimination rule of malfunction)
When three keyinputs or more is input, all the keyinput since the third is
made invalid.
However, when the number of all keyinput becomes two or less
because keyinput was lost, all keyinputs are made effective.
Dataline(bit7)
Dataline(bit6)
Dataline(bit5)
Dataline(bit4)
Dataline(bit3)
Dataline(bit2)
Dataline(bit1)
Dataline(bit0)
Dataline(bit7)
Dataline(bit6)
Dataline(bit5)
Dataline(bit4)
Dataline(bit3)
Dataline(bit2)
Dataline(bit1)
Dataline(bit0)
Dataline(bit7)
Dataline(bit6)
Dataline(bit5)
Dataline(bit4)
Dataline(bit3)
Dataline(bit2)
Dataline(bit1)
Dataline(bit0)
Dataline(bit7)
Dataline(bit6)
Dataline(bit5)
Dataline(bit4)
Dataline(bit3)
Dataline(bit2)
Dataline(bit1)
Dataline(bit0)
Dataline(bit7)
Dataline(bit6)
Dataline(bit5)
Dataline(bit4)
Dataline(bit3)
Dataline(bit2)
Dataline(bit1)
Dataline(bit0)
Com.line1(Xm+4)
Com.line2(Xm+5)
Com.line3(Xm+6)
Com.line4(Xm+7)
Com.line5(Xm+8)
Com.line6(Xm+9)
Com.line7(Xm+10)
Com.line8(Xm+11)
Com.line1(Xm+4)
Com.line2(Xm+5)
Com.line3(Xm+6)
Com.line4(Xm+7)
Com.line5(Xm+8)
Com.line6(Xm+9)
Com.line7(Xm+10)
Com.line8(Xm+11)
Com.line1(Xm+4)
Com.line2(Xm+5)
Com.line3(Xm+6)
Com.line4(Xm+7)
Com.line5(Xm+8)
Com.line6(Xm+9)
Com.line7(Xm+10)
Com.line8(Xm+11)
Com.line1(Xm+4)
Com.line2(Xm+5)
Com.line3(Xm+6)
Com.line4(Xm+7)
Com.line5(Xm+8)
Com.line6(Xm+9)
Com.line7(Xm+10)
Com.line8(Xm+11)
Com.line1(Xm+4)
Com.line2(Xm+5)
Com.line3(Xm+6)
Com.line4(Xm+7)
Com.line5(Xm+8)
Com.line6(Xm+9)
Com.line7(Xm+10)
Com.line8(Xm+11)
Com.line1(Xm+4)
Com.line2(Xm+5)
Com.line3(Xm+6)
Com.line4(Xm+7)
Com.line5(Xm+8)
Com.line6(Xm+9)
Com.line7(Xm+10)
Com.line8(Xm+11)
State (a) State (b) State (c)
State (d) State (e) State (f)
d : Keyswitch OFF(“0”)
D : Keyswitch ON(“1”)
Dataline(bit7)
Dataline(bit6)
Dataline(bit5)
Dataline(bit4)
Dataline(bit3)
Dataline(bit2)
Dataline(bit1)
Dataline(bit0)
(Operation of ladder program)
The example of the operation of ladder program is shown about matrix
DI composed of 8bits x 8commo
ns as follows.
(1) The number of datalines where the keyinput exists is examined.
Logical add R1 of the data of all addresses is calculated. The number
of bits which are ”1” in the 8bits data of R1 corresponds to the number
of datalines where the keyinput exists.
6.12.8
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