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.

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.

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.