IMCB02-E5 7
6. OPERATIONS
6.1 Operation procedures
(1) Prior to starting operation, check that the mounting and wiring
have been finished, and that the SV and various parameters
have been set.
(2) As this instrument does not have a power supply switch, it is
ready to operate as soon as the power is turned on. Prior to
factory shipment, the instrument is set to "RUN (operation
start)."
•
If the instrument is switched to operation stop (STOP), its display,
output, etc. become as follows.
•
Display : The PV display unit
shows (STOP).
•
Output: Control output OFF, Alarm output OFF
•
Suspended when the AT function is activated. (The PID
constants are not updated.)
•
Stopped when the ST function is activated. (Re-started in RUN
mode.)
•
This instrument holds the conditions that exist just before the
power is turned on. For example, if the power is turned off in
STOP mode, the instrument starts in STOP mode when the power
is turned on again.
6.2 Set data lock (LCK) function
The set data lock function is used to prevent misoperation by not
setting any parameter which is not used frequently. The parameter
thus locked cannot be set or changed, but can only be monitored.
6.3 Autotuning (AT) function
The AT function automatically measures, computes and sets the
optimum PID and LBA constants. This function is activated after-
ON, during temperature rise and/or when control is stabilized from
any process state.
!"
!"
!"
!"
Requirements for AT start
Start AT when all the following conditions are satisfied:
•
Prior to starting the AT function, end all the parameter settings
other than PID and LBA.
•
Confirm the LCK function has not been engaged.
!"
!"
!"
!"
Requirements for AT suspension
The AT function is suspended if any of the following conditions is
established:
•
When the SV is changed.
•
When the PV bias value is changed.
•
When the RUN/STOP function is changed to the "STOP."
•
When the PV becomes abnormal. (According to the burnout.)
•
When the power is turned on.
•
When a power failure longer than 20 ms occurs.
•
When the AT function does not end in about 9 hours after tuning
started.
•
If the AT suspension condition is established, the AT function is
immediately suspended to be changed to PID control.
The PID and LBA constants at this time are the same as before
starting AT. In addition, even if the AT is completed, it is
automatically transferred to PID control.
•
If any problems arise due to hunting exists in the control system,
do not use the AT function. In this case, set each value to match
the controlled object.
6.4 Self-tuning (ST) function
The ST function is used to automatically calculate and set adaptive
PID constants anytime when the power is turned on; the SV is
changed or the control system becomes oscillatory as the
characteristic of the controlled system varies.
••••
In a controlled system in which ripples may be contained by
the application of periodic disturbances, use this instrument
with the ST function turned off.
••••
When the power is turned on or the SV is changed with the
ST function turned on, turn on the power of the controlled
system (heater, etc.) before or just when the power of this
instrument is turned on.
!"
!"
!"
!"
Requirements for ST start
Start ST when all the following conditions is satisfied: The
instrument should be in PID control. (P
≠
0, I
≠
0, D
≠
0 and ARW
≠
0.)
!"
!"
!"
!"
Requirements for ST stop
The ST function is stopped if any of the following conditions is
established:
•
When PV is out of the input range
(When the instrument is overscaled or downscaled)
•
When the ST function is set to the OFF state.
•
When the AT function is activated.
*1
•
When the RUN/STOP function is changed to the "STOP."
*2
•
When the power is turned off.
*1:
If the AT function is activated, the ST function is set to the stop
state. After the AT function is stopped, the ST function re-starts
from the stop state.
*2:
If the operation state is changed from the "RUN" to "STOP," the
ST function is set to the stop state. If the operation state is
changed from the "STOP" to "RUN," the ST function re-starts
from the stop state.
•
When control action is in heat/cool PID action, the ST function is
not activated.
•
The PID and ARW settings cannot be changed while the ST
function is being activated. However, they can only be monitored.
NOTES
NOTES
CAUTIONS
NOTES
CAUTIONS
#"
Connect the input signal wiring, and then turn on the power. If the input signal wiring opens, the instrument judges the input
is disconnected.
•
Upscale
*1
: TC input , RTD input (Downscale when the input is shorted.)
•
Downscale
*1
: TC input (To be specified when ordering), Voltage input (Current input)
*2
*1 : Alarm output ON (However, for the W or A control action type, the control output on both heat-side and cool-side is
turned off.)
*2 : For 0 to 5 V DC or 0 to 20 mA DC, both control and alarm outputs are indefinite.
#"
No influence is exerted upon the instrument for power failure of 20 ms or less. For power failure of more than 20 ms , the
instrument performs the same operation as that at the time of power on after power recovery (This applies only when
alarm action is turned off).
#"
The alarm hold action is activated when not only the power is turned on, but also the SV is changed.
