Omron SYSMAC CS Series Operation Manual page 40

Outline
PID Constant Bank
Selector Block
(Block Model 168)
Split Converter Block
(Block Model 169)
Disturbance Overshooting
Suppression
Note
MV Limit Alarm Stop
Switch
MV Error Control Stop
Switch
Calculate High Speeds
with Ramped Switch
(Block Model 167)
8
The PID constant bank selection function supported by OMRON Thermac R-
series Temperature Controllers can now be used simply with PLCs. The Bank
Selector block (Block Model 168) is used together with the Basic PID block
(Block Model 011), Advanced PID block (Block Model 012), or Blended PID
block (Block Model 013).
Up to 8 sets (bank numbers 1 to 8) can be recorded for each of the P, I, D, MH,
ML, and local SP values. The bank numbers can be switched and the
recorded bank data can be written all at once to the P, I, D, MH, ML, and local
SP values in the Basic PID or Advanced PID block at the connection destina-
tion, according to the analog input range or the ON status of input bits 1 to 8.
The autotuning results of Basic PID and Advanced PID blocks can also be
reflected in the PID setting for the current bank.
The Split Converter block (Block Model 169) is used in combination with the
Basic PID block (Block Model 011) or Advanced PID block (Block Model 012).
The MV output value is converted into two analog outputs for V characteristics
or parallel characteristics (e.g., MV for heating and MV for cooling) and output.
Both a heating side PID SP and cooling side PID SP are provided, and the
PID block SP at the MV connection source can be changed according to
whether the output is for heating or cooling. Conversely, autotuning results for
the PID blocks can also be reflected in either the PID constant for heating or
cooling.
This block simplifies continuous proportional control for heating/cooling, which
previously needed to be combined with segment approximation.
A disturbance overshooting suppression function has been added for the
Basic PID block (Block Model 011) and Advanced PID block (Block Model
012). Therefore, the influence of disturbance can be suppressed in applica-
tions that require high-speed response control, in particular (such as ceramic
heater control, flowrate control, and pressure control).
When disturbance overshooting suppression is enabled, the influence of dis-
turbance can be suppressed by setting the characteristics for disturbance
(disturbance gain and time constant of disturbance) that enters the control
system. Once the error has entered the disturbance stabilization zone (error
considered to be stabilized), the disturbance overshooting control function is
automatically started if the disturbance width is exceeded.
This function is disabled during autotuning, while changing the target value
(changing width exceeding the disturbance stabilization band), and during PD
control.
In Control blocks, such as Basic PID, even if the MV reaches the MV upper or
lower limit when the MV Limit Alarm Stop Switch turns ON, the MV Upper
Limit Flag or MV Lower Limit Flag is disabled and will not be set to ON. (The
MV limit will operate, however.).
In Control blocks, such as Basic PID, the MV Error Control Stop Switch turns
ON when an MV error occurs at the MV output value before MV traceback,
and the MV is maintained.
The calculation cycle for the Ramped Switch (Block Model 167) can be speci-
fied as 0.01 s, 0.02 s, or 0.05 s.
Section 1-1