TON and TAON provide the capability to delay the effect of an input changing from OFF to ON after a specified amount of time. When the input turns ON, a timer begins incrementing from its initial value to the specified value. When the specified value is reached, the output is turned ON. TON increments every 0.01 seconds and TAON increments every 0.1 seconds.
|Type of Timer||Time units||Maximum Time|
|TON||0.01 sec||655.35 sec|
|TAON||0.1 sec||6553.5 sec|
For TON and TAON there are 2 parameters. The first parameter can be any value from T0 through T99, and the second parameter can be any numeric constant or data register, such as D0.
In the ladder above, when START turns ON, the timer increases from 0 to 100 in increments of 0.01 seconds. When 100 is reached, T0 will turn ON. Here, 100 is equal to a time of 1 second for TON, and 10 seconds for TAON.
When START turns OFF, the timer is reset to its initial value and T0 will turn OFF. TON and TAON will reset their values upon powering OFF. Using KTON and KTAON, the battery backup feature can be used to retain the timer's values between power cycles. The example below illustrates how to reset TAON.