Mitsubishi Electric MELSEC System Q, Special Instructions Manual

Page: 248 / 316

246
6 PID CONTROL INSTRUCTION
6.2 PID Control Instruction (Exact Differential)
*1 For process value after filtering (PVf), the value calculated based on the process value of input data are stored.
For the operational expression, refer to the following.

MELSEC-Q/L/QnA Programming Manual (PID Control Instructions)
(s)+16 Alarm ALARM • Used to determine if the
change rate of the MV
(manipulated value) and
the PV (process value) is
within or outside the limit
value range.
• Once set, the alarm data
are maintained until the
user resets it.
When the MV variation is outside the limit
range, bit 1 (b1) is set to '1'.
When the PV variation is outside the limit
range, bit 0 (b0) is set to '1'.
User
System

(s)+17

(s)+27
PID control work area
(reserved by the system)   
I/O data area for No. 2 loop (device: (s)+28 to (s)+45)
(s)+28 Setting
value SV The same as I/O data area for No. 1 loop
(s)+29 Process
value PV
(s)+30 Automatic
manipulated
value MV
(s)+31 Process
value after
filtering PVf
(s)+32 Manual
manipulated
value MV
MAN
(s)+33 Manual/
automatic
selection MAN/
AUTO
(s)+34 Alarm ALARM
(s)+35

(s)+45
PID control work area
(reserved by the system)
  
I/O data area for No. n loop
(s)+(m+0) Setting
value SV The same as I/O data area for No. 1 loop
m=(n-1)

18+10
n: number of loops
(s)+(m+1) Process
value PV
(s)+(m+2) Automatic
manipulated
value MV
(s)+(m+3) Process
value after
filtering PVf
(s)+(m+4) Manual
manipulated
value MV
MAN
(s)+(m+5) Manual/
automatic
selection MAN/
AUTO
(s)+(m+6) Alarm ALARM
(s)+(m+7)

(s)+(m+17)
PID control work area
(reserved by the system)
  
Device Data name Description Setting range Setting
side Processing when the
setting data are outside
the setting range
With PID limits Without PID
limits
…
b15
0 (2)
b1 b0
(1)