Welcome to Part 6 on Mitsubishi FX PLC GX Works 2 tutorial.

In the previous tutorial (part 5) we have discussed the timers

of the Mitsubishi FX PLC and those were on delay timers.

There is an Off Delay type of timer but not available to some models of Mitsubishi PLC.

In this tutorial we will make a program so that we can have an Off Delay timer

using an On Delay timer.

Before that I will explain what is the difference between

On delay timer and Off delay timer.

In this timing chart we can see the difference between the two timers.

With on delay timer, when the drive input (X0) is closed,

the timer will start counting

until it reaches the specified set value.

When the counted value is equal to the set value, the timer contact turns on.

When the timer contact closes, the the output coil turns on.

As long as the drive input in On the timer remains On and so the output coil.

When the drive input is switched off, immediately the timer will turn off

and eventually the output coil Y0.

While on the off delay timer, when the drive input X0 is turned on

the output coil will also turn on.

While the drive input is on, the off delay timer will not start counting

and the output remains on.

When the drive input is switched off, the off delay timer will start counting

until it reaches the set value.

The output coil is then switched off.

Therefore there is a time delay to off the output after the input drive has been switched off.

Now we will create some programs that will function as an off delay timer.

When input X1 is switched on, the output coil Y1 is turned on.

If input X1 is switched off timer T1 will start counting

but output coil will remain turned on because of the latched contact.

After input X1 has been switched off the timer starts counting.

While the output Y1 remains on.

When the count value reaches the set value equivalent to 20 seconds,

the normally closed timer contact will open and output Y1 will be turned off.

That is one example on how to program an off delay timer.

Now we will make another program for an off delay timer.

Now we will see the function of the new off delay program.

When input X2 is switched on, output Y2 is turned on.

If input X2 will be switched off, output Y2 should remain on.

and the timer will start counting.

When the counter value reaches the 20 seconds set value

output Y2 will turn off because normally closed timer contact will open.

Therefore we have an off delay on the output after the input has been switched off.

We will make a third example program for an off delay timer.

This time we will use a Set and Reset instruction.

When input X4 is switched on, output Y4 is set.

If input X4 is switched off, the timer will start counting

but output Y4 will remain on due to the Set instruction.

When the timer set value is reached the timer contact will close.

Output Y4 will then be reset.

Now we will switch off input X4.

The timer starts counting.

When the set value of 20 seconds is reached,

this timer contact will close to reset Y4.

Those are the examples on how to make an off delay timer

since some FX PLCs like the FX1S, FX1N and FX3G don't have it.

On the next video tutorial we will be discussing about counters.

Thank you for watching.