Troubleshooting; Fuzzy Self-Tuning - Omron E5CN Manual

E5CN

TROUBLESHOOTING

When an error occurs, an error code will be displayed on the No. 1 display. Check the contents of an error and take appropriate
countermeasures.
No. 1 display Type of error
 
Input error

Memory error
Display range over
 
HB error
Note: Error will be displayed only when the display is set for the PV or PV/SP.

Fuzzy Self-tuning

The fuzzy self-tuning (ST) is a function that automatically calculates an optimum PID constant depending on items to be controlled.


FEATURE
The Temperature Controller determines when to execute this fuzzy self-tuning.


FUNCTIONS
SRT: Performs PID tuning according to the step response method when the SP is changed.
LCT: Performs PID tuning according to the limit cycle method when the SP is changed.
Requirements for SRT Functionality
The ST will be executed according to the step response method when the following conditions are satisfied when operation is started or
when the SP is changed.
When operation is started
1. The SP at the startup is different from the SP at the time the
previous SRT was executed. (See Note.)
2. The temperature upon startup is smaller than the SP in the
reverse operation and larger than the SP in the direct
operation.
3. Restarting of operation is not due to an input error.
Note: The "SP that existed when the previous SRT was
executed" refers to the SP used for obtaining the PID
constant in the previous SRT.
If the SP is changed while SRT is being executed and if SRT completion conditions are satisfied, no PID change will take place.
Stabilization State
Measured values remain in the stable range for a certain period
of time.
Balanced State
Output is 0% for 60 seconds and measured values fluctuate
within the width of the stable range.
Countermeasures
Check the wiring of inputs for miswiring, disconnections, short-circuits, and the input
type.
First, turn the power OFF then back ON again. If the display remains the same, the
Unit must be repaired. If the display is restored, then a probable cause can be external
noise affecting the control system. Check for external noise.
Though not error, this is displayed when the process value exceeds the display range
when the control range is larger than the display range.
•
When less than "-1999"
•
When larger than "9999"
First, turn the power OFF then back ON again. If the display remains the same, the
controller must be repaired. If the display is restored, then a probable cause can be
electrical noise affecting the control system. Check for electrical noise.
When SP is changed
1. The SP after change is different from the SP at the time the
previous SRT was executed. (See Note.)
2. In the reverse operation, the value obtained by deducting the
SP before change from the SP after change is larger than the
ST stable range. In the direct operation, the value obtained by
deducting the SP after change from the SP before change is
larger than the ST stable range.
3. The SP change width is larger than the current proportional
band x 1.27 + 4.
4. The temperature is in the stable state. (It can be in the
balanced state if no output is generated when the power is
turned ON.)
Tempera-
ture
This inclination is referred to as
ST stable range
R.
SRT completion
Time
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