Mitsubishi Electric MELSEC-Q/L Programming Manual page 1069

■Cautions on using timers
QCPU, LCPU updates the present value of timers and turns ON/OFF the contacts of them at the execution of OUT T
instruction.
Therefore, if "Present value  Set value" when the timer coil is turned ON, the contact of that timer is turned ON.
When creating a program in which the operation of the timer contact triggers the operation of another timer, create the
program for the timer that operates later first.
In the following cases, all timers go ON at the same scan if the program is created in the order the timers operate.
• With high speed timers, if the set value is smaller than a scan time.
• With slow timers, if "1" is set.
Ex.
For timers T0 to T2, the program is created in the order the timer operates later.
T1
K1
T2
T0
K1
T1
X0
K1
T0
Ex.
For timers T0 to T2, the program is created in the order of timer operation.
X0
K1
T0
T0
K1
T1
T1
K1
T2
Comparison of counters
Function
Designation method
Index modification Contact
Coil
Set value
Present
value
Update processing for present value
Contact ON/OFF processing
*1 The Q00J/Q00/Q01CPU can use Z0 to Z9.
The Universal model QCPU/LCPU can use Z0 to Z19.
*2 The universal model high speed type QCPU can use those other than Z0 and Z1.
T2 timer starts measurement from the next scan after turning the contact of T1 ON.
T1 timer starts measurement from the next scan after turning the contact of T0 ON.
T0 timer starts measurement when X0 is turned ON.
T0 timer starts measurement when X0 is turned ON.
Contacts of T1 and T2 timers are turned ON when contact of T0 is turned ON.
QCPU/LCPU
K100
C0
• Enabled (only Z0 and Z1 are usable)
• Enabled (only Z0 and Z1 are usable)
• Disabled
• Enabled (Z0 to Z15 are usable)
• When OUT Cn instruction is executed
AnUCPU
*2
• Enabled
*2
• Disabled
• Disabled
*1
• Enabled
• When END processing is done
Appendix 2 CPU Performance Comparison
AnACPU AnNCPU
K100
C0
• Disabled
• Disabled
• Disabled
• Enabled
APPENDICES
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