CCW/Timers Reset

Hello All,
Can someone please tell me how to keep a timer from resetting or simply hold it's value until it is is manually reset?

This should be an easy task but I'm missing something. I have a simple start stop latching circuit that controls a TON timer. I'm trying to capture the value from the timer, display it, then reset it at the customer's convenience. Instead, every time the timer goes from true to false, it resets.

Thanks!

I'm still new to programming ladder logic, but if it were me, I would make a rung under the timer that compares a "Great-Than" block of the timer value greater than zero, so that when its greater than zero it passes through. Afterwards, make it use a"MOV" block to move that value into a variable. When the timer resets it wont be true therefore it wont overwrite the value. Use that stored value to display for the customer.

Also include a condition that a "reset" button must be pressed before the timer will restart/start. This will allow the stored value to stay at its "maximum" before being re-written after its reset and the TON is > 0.

It depends on the PLC you use but in Rockwell Universe it would be an RTO, a "retentive timer on delay"

The key word here is rententive

When I am looking to to display the accumulated time for the customer, I typically run the timer only when the function is occurring, then on the same rung convert the accumulated time to a REAL value.

Now when the function stops, the timer is reset, but the REAL value remains. The REAL value then resets as soon as the timer starts again.

Thanks for all of the input. If the people who made this software would have known a little more about RS500 this would be a pretty decent product, however it most certainly is a far cry from anything RA...no RTO timer, no TT instruction, no...etc...etc...etc.

This was the only way I could get it to work. I'm sure there is a better way, but this does work.

Rung 1. A Direct Contact tagged "Timer_Enable" then the TON_1 instruction.

Rung 2. A Greater Than instruction with i1 being TON_1.ET, i2 being T#0S, then a ANY_TO_REAL instruction with i1 being TON_1.ET and o1 being "T_1_TT"

Rung 3. (This is primarily for the read-out on the Maple HMI) Multiply instruction with i1 being "T_1_TT"and i2 being 0.001 and o1 being "Adjusted_Value"

Rung 4. Direct Contact "Reset" followed by a MOV instruction with i1 being 0.0 and o1 T_1_TT.

This is a little different that I originally wanted it to (or thought it should) be. But at the end of the day, the timer works on an input (Timer_Enable) and stops when that input drops out and the counter retains it's value and can be manually reset.

Thanks Again!

P.S. If anyone is using this with a Maple HMI, the numeric object tag is Adjusted_Value using 32-bit Float for the format and 2 places left and right of decimal.