Mitsubishi MELSEC-Q series Programming Manual page 59

Set Data
Processing contents
(1) Range check
(a) A range check is performed on the input value (E1).
An alarm is output if the input value (E1) exceeds the upper/lower limit value.
Range check
E1  HH
Upper limit check
E1  H
H < E1 < HH
E1  LL
Lower limit check
E1  L
LL < E1 < L
*1 When SEI or ERRI in the alarm detection inhibition (INH) is set to 1, SEA, BB1, BB2 and BB3 show 0 since the alarm is
prohibited.
(b) Last value hold processing
When a range excess occurs (BB1 = 1) in the range check, whether operation will be continued unchanged or the
S.IN instruction will be terminated is judged depending on whether SM1500 is ON or OFF.
1) When SM1500 is OFF (not in the hold mode), "(2) Input limiter processing" is performed if a range excess
occurs (BB1 = 1).
2) When SM1500 is ON (in the hold mode), the following processing is performed and the S.IN instruction is
terminated if a range excess occurs (BB1 = 1).
• BW retains the last value.
• Error information is set in BB.
(2) Input limiter processing
Upper/lower limiter setting is made on the input value (E1).
Condition
E1  NMAX
E1  NMIN
NMIN < E1 < NMAX
Condition
BB2
*1
1
0
Last value
––
––
––
Result (T1)
NMAX
NMIN
E1
Range check result (alarm output)
BB3
––
––
––
*1
1
0
Last value
S.IN
BB1, SEA
*1
1
0
Last value
*1
1
0
Last value
1
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