Mitsubishi Electric MELSEC iQ-R Series - Page 1287

11 PROCESS CONTROL INSTRUCTIONS
11.3 Control Operation Instructions
1285
11
■Engineering value inverse transformation (1)
The instruction performs the following operations to match the ranges of PH, PL, HH, and LL to the input values (E1).
■Upper/lower limit check (2)
The upper and lower limits of the input value (E1) are checked under the following conditions.
*1 If ERRI or PHI of disable alarm detection (INH) is set to 1, PHA of ALM and BB2 are set to 0.
*2 If ERRI or PLI of disable alarm detection (INH) is set to 1, the PLA of ALM and BB3 are set to 0.
*3 If ERRI or HHI of disable alarm detection (INH) is set to 1, HHA of ALM is set to 0.
*4 If ERRI or LLI of disable alarm detection (INH) is set to 1, LLA of ALM is set to 0.
■Variation rate check (3)
• A variation rate check is performed for the duration specified by the variation rate alarm check time (CTIM). The number of
executions of a variation rate check is determined by the following expression.
Set CTIM and T so that m  2.
No processing is performed when m = 0 (integral part).
Ex.
When m = 4, operations are performed as shown below.
Check item Condition ALM BB2 BB3
Upper limit check E1 > PH' PHA = 1
*1
1
*1

E1PH' - HS PHA = 0 0 
Others PHA: The last value is held.
*1
Hold
*1

Lower limit check E1 < PL' PLA = 1
*2
 1
*2
E1PL' + HS PLA = 0  0
Others PLA: The last value is held.
*2
 Hold
*2
Upper upper limit check E1 > HH' HHA = 1
*3

E1HH' - HS HHA = 0 
Others HHA: The last value is held.
*3

Lower lower limit check E1 < LL' LLA = 1
*4

E1LL'+HS LLA = 0 
Others LLA: The last value is held.
*4

(1) 0th time: E1
n
-E1
n-4
(2) 1st time: E1
n
-E1
n-4
(3) 2nd time: E1
n
-E1
n-4
(4) 3rd time: E1
n
-E1
n-4
(5) 4th time: E1
n+4
-E1
n
Ec: Execution cycle
PH'= ×(PH-RL)
RH-RL
100
PL'= ×(PL-RL)
RH-RL
100
HH'= ×(HH-RL)
RH-RL
100
LL'= ×(LL-RL)
RH-RL
100
m=
©T
CTIM
E1
n
E1
n+1
E1
n+2
E1
n+3
E1
n+4
(1) (2) (3) (4) (5)
CTIM
DPL
t
Ec