Panasonic GTWIN, Reference Manual

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GTWIN Reference Manual
1.6 GT Configuration
37
1.6.7.1 Countdown timer
The countdown timer counts down from the start value in seconds until the elapsed value is 0.
There are sixteen countdown timers (number 0 to F) available. Every countdown timer needs
two devices: one for controlling the start and completion of the countdown (control device),
one for storing the start and the elapsed value (counter device).
Control device Controls the start and completion of the countdown.
Counter Device Stores the start and the elapsed value.
Control device
The control device uses two words beginning from the starting address specified. The first
word stores the start bit, the second the completion bit. The countdown begins when the start
bit is turned ON. When the elapsed value becomes 0, the start bit is turned OFF and the
completion bit is turned ON.
Address Timer number
F E D C B A 9 8 7 6 5 4 3 2 1
N Start bit
N+1 Completion bit
Counter device
Sets the starting address for the start value (0
–
65535) and the elapsed value. The start value and the elapsed value
are stored in the sixteen words after the starting address.
Address Timer number Contents
N+0 0
Start value and elapsed value
N+1 1
N+2 2
N+3 3
N+4 4
N+5 5
N+6 6
N+7 7
N+8 8
N+9 9
N+10 A
N+11 B
N+12 C
N+13 D
N+14 E
N+15 F