GE GFK-0804B manual Off Timer, Example and HHP Instructions

4

Off Timer

The Off Timer turns OFF an output after a specified time period. The time period can be from 0 to 6553.5 seconds. However, if a constant is used for the Preset value, the time period can be from 0 to 3276.7 seconds.

To program a timer function, enter two inputs (in the example below, I1, and I2), and two parameters (R1 and R385 in the example). In this example, the timer length is not specified directly. Instead, this example uses the register R385 as the second parameter. In this case, register R385 contains the value 100. The timer length can be placed in that register either by program logic or from the Hand-held Progammer or programming software.

When the program encounters a register location as the second parameter of the timer, it looks in that register for the value it contains, and uses that value as the timer length. So for this example, timing is the same as for the previous example.

The current timer value (in R1 above) will not increment beyond its programmed length (time period), even if I1 remains closed and I2 remains open.

Programming Software Instructions

If you are using the programming software, refer to the instructions on page 4-16.

Example and HHP Instructions

46027

Ladder Diagram

I1C1

R1

OFTMR

I2

R385

Timing Diagram

Input I1

Input I2

Hand-held Programmer
START		I1
START		I2
TIMER	F1	R1
		R385
OUT		C1

When I1 is 1, the timer is started. The timer setting is:

100 x 0.1 = 10 Sec.

Register R1

Coil C1

100

During the operation of the timer, if I1 switches to 0, the timer is on hold. When I1 is 1 again, the timer resumes timing,

0

When the timer reaches the set value (10 seconds), output coil C1 deactivates.

Input I2 is used to reset the timer. When both I1 and I2 are ON, the timer remains reset.

4-18 Micro PLC Programmer's Guide ± April 1994 GFK-0804B