Справочник Пользователя для Mitsubishi Electronics MELSEC -Q/L

7  APPLICATION INSTRUCTIONS
7.10  Debugging and Failure Diagnosis Instructions

Processing details

 • The check ladder pattern that will be used in the CHK instruction can be updated to any format desired. The actual failure 

checks are conducted with the CHKST and CHK instructions.

 • Failure checks are conducted according to the check conditions designated by the CHK instruction and the ladder pattern 

described between the CHKCIR and CHKEND instructions.

 • Refer to Page 520 Special format failure check for more information on the CHKST and CHK instructions.
 • To change the check format of the CHK instruction using the CHKCIR to CHKEND instructions, the user 

should create a ladder with index modification (Z0).

(1) Page 520 Special format failure check

J\

U\G

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Basic

Universal

LCPU

SM400

SM400

CHKST

CHK

CHKCIR

CHKEND

Fn

Fn

Fn

X

X

X

X

(1)

Ladder pattern to be checked

Max. 9 coils

Command