Mitsubishi Electronics manual 163

11 TROUBLESHOOTING

MELSEC-Q

Special Relay List

(3) System clocks/counters

Number

Name

Meaning

Explanation

Set by

Corresponding

Applicable

(When Set)

ACPU

CPU

M9

SM400

Always ON

ON

• Normally is ON

S

M9036

(Every END

OFF

processing)

SM401

Always OFF

ON

S

• Normally is OFF

(Every END

M9037

OFF

processing)

ON for 1 scan

ON

1 scan

• After RUN, ON for 1 scan only.

S

SM402

• This connection can be used for scan execution type

(Every END

M9038

only after RUN

OFF

programs only.

processing)

After RUN, OFF

ON

• After RUN, OFF for 1 scan only.

S

SM403

1 scan

• This connection can be used for scan execution type

(Every END

M9039

for 1 scan only

OFF

programs only.

processing)

Low speed

• After RUN, ON for 1 scan only.

S

execution type

ON

1 scan

SM404

program

• This connection can be used for low speed execution

(Every END

New

OFF

ON for 1 scan

type programs only.

processing)

only after RUN

Low speed

• After RUN, OFF for 1 scan only.

S

execution type

ON

SM405

program

1 scan

• This connection can be used for low speed execution

(Every END

New

OFF

After RUN, OFF

type programs only.

processing)

for 1 scan only

• Repeatedly changes between ON and OFF at 5-ms

interval.

SM409

0.01 second

0.005 sec.

• When PLC power supply is turned OFF or a CPU module

S (Status

New

QCPU

0.005 sec.

reset is performed, goes from OFF to start.

clock

• Note that the ON-OFF status changes when the

change)

designated time has elapsed during the execution of the

program.

SM410

0.1 second clock

0.05 sec.

0.05 sec.

• Repeatedly changes between ON and OFF at each

M9030

designated time interval.

0.1sec.

SM411

0.2 second clock

0.1sec.

• When PLC power supply is turned OFF or a CPU module

M9031

S (Status

reset is performed, goes from OFF to start.

0.5 sec.

change)

SM412

1 second clock

0.5 sec.

• Note that the ON-OFF status changes when the

M9032

designated time has elapsed during the execution of the

1 sec.

SM413

2 second clock

1 sec.

program.

M9033

• Goes between ON and OFF in accordance with the

number of seconds designated by SD414.

SM414

2n second clock

n sec.

• When PLC power supply is turned OFF or a CPU module

S (Status

M9034 format

n sec.

reset is performed, goes from OFF to start.

change)

change

• Note that the ON-OFF status changes when the

designated time has elapsed during the execution of the

program.

• Switches between ON and OFF in accordance with the

number of milliseconds designated by SD415.

SM415

2n (ms) clock

n(ms)

• When PLC power supply is turned OFF or a CPU module

S (Status

New

QCPU

n(ms)

reset is performed, goes from OFF to start.

change)

• Note that the ON-OFF status changes when the

designated time has elapsed during the execution of the

program.

SM420

User timing clock

M9020

No.0

SM421

User timing clock

• Relay repeats ON/OFF switching at fixed scan intervals.

M9021

No.1

• When PLC power supply is turned OFF or a CPU module

S

User timing clock

SM422

reset is performed, goes from OFF to start.

(Every END

M9022

No.2

• The ON/OFF intervals are set with the DUTY instruction.

processing)

User timing clock

SM423

DUTY

n1

n2

SM420

M9023

No.3

SM424

User timing clock

n2

n2

M9024

No.4

scan

scan

SM430

User timing clock

n1

No.5

scan

SM431

User timing clock

No.6

S

User timing clock

SM432

• For use with SM420 to SM424 low speed programs.

(Every END

New

No.7

processing)

SM433

User timing clock

No.8

SM434

User timing clock

No.9

11 - 47

11 - 47