E5AX-P
E5AX-P
11
Starting Control Operation
The E5AX will start control operations as soon as power is turned on
until power is turned off. If you don’t want control operations to be
performed while setting parameters, turn off the power and then turn
it back on after setting the desired parameters.
Auto-tuning
When the Level Key and Mode Key are pressed at the same time for
1 second minimum, the Temperature Controller automatically starts
tuning the PID constants. While auto-tuning is in operation, the au-
to-tuning indicator on the front panel will flash. The Temperature
Controller executes control based on the set PID constants (factory
set to P = 40
%
C, I = 240 seconds, and D = 40 seconds) until the tem-
perature of the controlled system reaches the set temperature. After
that, the Temperature Controller automatically adjusts the PID con-
stants using the limit cycle method. When the auto-tuning indicator
turns off, the auto-tuning is terminated and PID constants are re-
newed.
Main setting
Previous PID
constants
New PID constants
AT indicator flashes
Limit Cycle Method: the optimum PID constants are calculated by
this method by varing the control output variable and generating ex-
ternal oscillation.
Auto-tuning can be carried out regardless of whether the Tempera-
ture Controller is performing reverse (heating) or normal (cooling)
operation. To stop auto-tuning, hold down the Level Key and Mode
Key again simultaneously for 1 second minimum. All settings will re-
turn to those prior to the beginning of auto-tuning. Automatic tuning
can be executed at any time: at power application, while the temper-
ature is rising, or after the control action has stabilized.
Error Messages
The Temperature Controller is provided with self-diagnostic functions, and will display an error message on the PV display when an error is
detected.
Message
Cause
Control output
Alarm output
Normal
Reverse
ffff
Input temperature has exceeded the upper
limit of the temperature range by more than
20
%
C.
Open: OFF
Close: ON
Open: ON
Close: OFF
Sends alarm signal in ac-
cordance with the set
alarm mode.
––––
Input temperature has fallen below the lower
limit of the temperature range by more than
20
%
C.*
Open: ON
Close: OFF
Open: OFF
Close: ON
Sends alarm signal in ac-
cordance with the set
alarm mode.
5.err
(flashes)
The thermocouple has burned out or
short-circuit bar has been removed. The plati-
num resistance thermometer has burned out
or A and B terminals have been short-cir-
cuited.
Open: OFF
Close: ON
Open: ON
Close: OFF
Sends alarm signal in ac-
cordance with the set
alarm mode. Proportional
alarm output is OFF, how-
ever.
e111
(flashes)
e333
(flashes)
Memory failure (
e111
) or A/D converter failure
(
e333
) has occurred. Temperature Controller
must be repaired if recovery is not made by
turning power off once and on again.
Open: OFF
Close: OFF
Open: OFF
Close: OFF
OFF
*When the temperature resistance thermometer is used, this message is displayed when the temperature has fallen below -99.9
%
C.
