Mitsubishi Electric MELSEC iQ-R-R00CPU - Page 341

21 DEVICES
21.3 User Device
339
21
■Retentive timer (ST)
This device counts the sum of time duration in which the coil is turned on. When the retentive timer coil is turned on,
measurement starts and when the timer current value matches a setting value (when time is up), the retentive timer contact is
turned on. The current value and the contact on/off state is retained even when the retentive timer coil is turned off. When the
coil is turned on again, measurement starts with the retained current value. To clear the retentive timer current value and turn
off the contact, issue the RST ST instruction.
■Long retentive timer (LST)
This device counts the sum of time duration in which the coil is turned on. When the long retentive timer coil is turned on,
measurement starts and when the timer current value matches a setting value (when time is up), the contact is turned on. The
current value and the contact on/off state is retained even when the long retentive timer coil is turned off. When the coil is
turned on again, measurement starts with the retained current value. To clear the long retentive timer current value and turn
off the contact, issue the RST LST instruction.
The long retentive timer (LST) can be used in interrupt programs. ( Page 67 Interrupt Program)
(1) Even though the coil (1)) turns off, the current value is held.
(2) Even though the coil (1)) turns off, the contact remains on.
(1) Even though the coil turns off, the current value is held.
(2) Even though the coil turns off, the contact remains on.
0 01 … 150 150 151 … 199 200
X0
X0
X1
K200
ST0
ST0
ST0
Y10
RST
OFF
OFF
OFF
ON
ON
(1)
(2)
1)
3)
2)
Instruction execution
RST ST0
instruction (3))
Contact of
ST0 (2))
Current value of
ST0
Coil of ST0 (1))
15 seconds
5 seconds
0 1 … 150 150 151 … 199 200 0
ON
ON
OFF
X0
OFF
OFF
1.5ms
0.5ms
(2)
(1)
Coil of LST0
Current value
of LST0
Contact of
LST0
RST LST0
instruction
Instruction execution