- T0 - T199 timers works as Done bit of TON timer (time base-100ms).
- T200 - T245 timers works as Done bit of TON timer (time base-10 ms).
- T246 - T249 timers works as Done bit of retentive timer (time base- 1 ms).
- T250 - T255 timers works as Done bit of retentive timer (time base-100 ms).
- T256 - T511 timers works as Done bit of TON timer (time base- 1 ms).
You may be aware of the working of the TON timer and RTO timer, which works similarly of TON and Retentive timers in AB PLC, the only difference is you only get the done bit of timers in mitsubishi PLC.
To enter proper preset value to the timers of various time bases we need to convert the seconds into the respective time bases.
Below table shows the conversion of pre-set values into the respective time bases.
We can use the same timer to get the done bit and TT bit of the timer. By default we get the done bit from the timer and to get the TT bit of the timer we just need to replace the NO contact with NC contact with same timer address.
For example - we want to turn on the output Y000 for 10 sec when we pressed the input and another output Y001 after 10 sec and when second output gets ON first should gets OFF.
when we press the input X000 it set the memory bit M0 and latches the input.
In next rung this NO contact of M0 address is connected to the Timer function T0 with preset value of 10 sec.(As because the T0 timer has a 100 ms Time base).here K is a constant whose value is 100.
Now in next rung of program NO contact of M0, NC contact of T0 are connected to Output Y000, so when we press the input X000, M0 gets ON and until the Timer T0 finishes the preset value of 10 sec Output Y000 remain ON and after 10 sec NC T0 becomes open and NO To gets closed and Output Y001 gets ON.
In place of T0 timer we can use any timers from T0 - T511 but we need to calculate the time base accordingly.
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