Fx3s timer

[Fletcher87]

Hi all,

im using a fx3s along with a gt21 hmi, I’m asking for help with a timer programme, I looking to create a programme that will run a pump for 50 mins every 70 hrs of run time, I would like to adjust these values on the hmi as and when required.

is this possible?

thanks

[Colin Carpenter]

Yes, it's possible.

They key thing to remember is the magic number of +32,767 which is the highest decimal number that a 16 bit word (D register) can hold.

As most timers in the Mitsubishi world count in tenths of a second, the longest a normal timer can count up to is 32,767 / 10 = 3,276.7 seconds which equals 54.6 minutes, so you can use a normal timer for your 50 minute period (50 x 60 x 10 = 30,000 which is in range)

However, a normal timer cannnot time to 70 hours for the reasons explained above.

In 70 hours, there are 70 x 60 x 60 = 252,000 seconds (therefore too big to count in seconds)

However, there are 70 x 60 = 4,200 minutes, so fine to count the minutes.

So, the simple answer is to use the "special"  1 minute pulse bit ( address will be detailed in the manual), and use that in conjunction with the INC_P command to incremment a data register by one every time the special bit comes on ( It's on for 30 secs, off for 30 secs).

When that data register is equal to 4,200 (70 hours) then turn on the pump and when the normal timer times out, turn the pump off and pulse a value of zero into your "counter data register" so that it starts counting again.

[Fletcher87]

Ok thanks

i am bit of a novice with this, I will maybe need to look at the manual as I’m not 100% sure on the exact logic of it.

 

[Colin Carpenter]

Most of us learnt how to programme by reading the manuals ..... and getting confused by the deliberate mistakes that Mitsubishi seem to leave in them at random.

Scratching your head and working out how to do things for yourself is the only real way to get experience ..... there's plenty of clues in the post.