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6 timer processing method and accuracy, Timer processing method and accuracy – MITSUBISHI ELECTRIC 700 Series User Manual

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81

Description of devices

3

SEQUENCE PRO

G

RAM

M

ING

(2) 100ms retentive timers

1) A 100ms retentive timer is designed to time the ON period of the timer coil.

When its coil turns on, the timer starts timing the present value and maintains
the present value and contact ON/OFF state if the coil turns off.
When the coil turns on again, the timer resumes timing from the maintained
present value.

2) Use the RST T instruction to clear the present value and turn off the contact.

Fig 3.16 Timing Chart

3.9.6

Timer processing method and accuracy

(1) Timer processing method

The coil of the timer is turned on/off at execution of the OUT T instruction, and
the timer's present value is updated and its contact turned on/off at execution of
the END instruction.
1) When the coil of the timer turns on, the present value of that timer is updated

after execution of the END instruction, and when the timer times out, its contact
turns on.
(a) When the coil of the 10ms or 100ms timer turns off, the present value of

that timer is reset to 0 and the contact is also turned off after execution of
the END instruction.

(b) If its coil turns off, the 100ms retentive timer maintains the prevent value

and contact ON/OFF state.

2) When the timer is reset by the RST instruction, the present value of the timer is

reset to 0 and the contact turns off too at execution of the RST T instruction.

Ladder example

Timing chart

POINT

If the timer setting is "0", the setting becomes infinite and the timer does not time out.

Times ON of X5 for 20s.

Resets T5 contact and clears
present value when X6 turns on.

15s

Setting

ON

5s

OFF

T5 contact

Timer present
value

T5 coil

X5

OFF

ON

OFF

ON

OFF

OFF

ON

OFF

OFF

OFF

ON