Omron CJ - REFERENCE MANUAL 02-2010 Reference Manual page 689

Control data Item
Bit 00 of C+5 PID forward/reverse
designation
Bits 13 to 14 ID starting integral
of C+6 manipulated variable
designation (unit
version 4.0 or later
only)
Bit 12 of C+6 Manipulated variable
output limit control
Bits 08 to 11 Input range
of C+6
Bits 04 to 07 Integral and
of C+6 derivative unit
Bits 00 to 03 Output range
of C+6
C+7 Manipulated variable
output lower limit
C+8 Manipulated variable
output upper limit
Bit 15 of C+9 AT Command Bit
Bits 00 to 11 AT Calculation Gain
of C+9
C+10 Limit-cycle Hysteresis
Note 1 When the unit is designated as 1, the range is from 1 to 8,191 times the period. When the unit is designated as 9, the
range is from 0.1 to 819.1 s. When 9 is designated, set the integral and derivative times to within a range of 1 to 8,191
times the sampling period.
2 Setting the 2-PID parameter ( ) to 000 yields 0.65, the normal value.
3 When the manipulated variable output limit control is enabled (i.e., set to "1"), set the values as follows:
0000 MV output lower limit
CS/CJ/NSJ Series Instructions Reference Manual (W474)
Contents
Determines the direction of the proportional
action.
Determines the initial integral manipulated
variable when PID control is started (i.e., when
the input turns ON) .
Determines whether or not limit control will apply
to the manipulated variable output.
The number of input data bits.
Determines the unit for expressing the integral
and derivative constants.
The number of output data bits. (The number of
output bits is automatically the same as the
number of input bits.)
The lower limit for when the manipulated variable
output limit is enabled.
The upper limit for when the manipulated variable
output limit is enabled.
This control bit starts autotuning.
• Set the AT Command Bit to 1 to perform auto-
tuning. (Autotuning can be started while
PIDAT(191) is being executed.)
• This bit is turned OFF automatically when auto-
tuning is completed.
Autotuning will be interrupted if the AT Command
Bit is turned OFF manually. In this case, the PID
constants will be enabled if they were already
calculated when autotuning was interrupted.
Set this parameter to adjust the contribution of the
PID calculation results to the stored values.
Normally, leave this parameter set to its default
(0000).
• Increase the value when emphasizing stability.
• Decrease the value when emphasizing respon-
siveness.
Sets the hysteresis when the limit cycle is
generated. The default setting for reverse
operation turns ON the MV with a hysteresis of
SV 20%.
Increase this setting if a proper limit cycle cannot
be generated because the PV is unstable.
However, the AT accuracy will decline if the Limit-
cycle Hysteresis is higher than necessary.
MV output upper limit
Setting range
0: Reverse action
1: Forward action
Bit 14 = 0 and bit 13=0:
Start from same integral manipulated value
as manipulated variable output designation
(Pre-Ver. 4.0 operation).
Bit 14 = 0 or 1 and bit 13 = 1:
Bumpless operation (i.e., start from an
integral manipulated variable that will not
abruptly change the manipulated variable
output and result in a continuous change).
Bit 14 = 1 and bit 13 = 0:
Start with integral manipulated variable = 0.
0: Disabled (no limit control)
1: Enabled (limit control)
0: 8 bits 5: 13 bits
1: 9 bits 6: 14 bits
2: 10 bits 7: 15 bits
3: 11 bits 8: 16 bits
4: 12 bits
1: Sampling period multiple
9: Time (unit: 100 ms)
0: 8 bits 5: 13 bits
1: 9 bits 6: 14 bits
2: 10 bits 7: 15 bits
3: 11 bits 8: 16 bits
4: 12 bits
0000 to FFFF (binary)
(See note 3.)
0000 to FFFF (binary)
(See note 3.)
As a Control Bit:
• 0 1:
Executes autotuning.
• 1 0:
Interrupts autotuning.
(PID(191) turns the bit OFF automatically
when autotuning is completed.
As a Flag:
0: Autotuning is not being executed.
1: Autotuning is being executed.
0000 hex: 1.00 (Default)
0001 to 03E8 hex (1 to 1000);
(0.01 to 10.00, in units of 0.01)
0000 hex: 0.20% (Default)
0001 to 03E8 hex:
0.01 to 10.00% in units of 0.01%
FFFF hex: 0.00%
Note The percentage is with respect to the
input range.
Max. value of output range
3. Instructions
Change with ON
input condition
Not allowed
3
Allowed
Allowed
(These parameters
are read when
autotuning starts.)
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