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13 -
(3) Heater break alarm setting
•
The heater break alarm set screen is shown in case where heater break alarm option is added and heater break alarm of the alarm type select digit on
mode 2 screen is selected.
•
Displayed by pressing the
key on higher limit alarm set screen, upper row shows the real time current value and lower row shows alarm action
current set value.
•
Break alarm value can be selected from OFF and range of 0.1~50.0A, heater break alarm is disabled by selecting OFF.
•
By setting OFF during heater break alarm signal output, heater break alarm output is terminated.
•
For set value other than OFF, heater break alarm signal is output if the current that flows in case where control output (contact or SSR drive voltage)
is ON, is less than set value.
•
If LOCK mode is selected at heater break alarm action mode select digit on mode 2 screen and the break alarm signal is output, alarm signal is only
terminated by changing the break alarm value into OFF or shutting down power.
If REAL mode is selected and heater current is less than current value being set, break alarm signal is generated. If heater current exceeds the
current threshold (0.1A), output of break alarm is terminated.
•
With the
or
key, value at which heater break alarm signal should be output is set and registered with
key.
Example: In case of setting heater break alarm action point at 25.0A.
6. Supplement
6-1. Auto return function
When no key action is made for longer than three (3) minutes on each screen except heater break alarm value set screen, the screen moves back to the
basic screen of the mode 0 screen group (auto return).
6-2. PID (Screen No.2,4 and 5 of mode 1 screen group)
PID values are automatically set by performing auto tuning, modification may be required for object to be controlled.
If auto tuning is not performed, PID values should be set. Description for PID is as follows:
(1) P (proportional action)
Control output rate (%) is set for measuring range.
Control output value changes in proportion with measured value (PV) and set value (SV).
For wide proportional band, change of control output is small relative to deviation. The narrower the proportional band is, the larger the output
variation is and the more intense proportional action is. Too narrow proportional band causes ON-OFF like action with oscillation (hunting). By setting
P to be OFF, ON-OFF action is performed.
(2) I (integral time)
A function that compensates the offset created by proportional action. Effect of compensation is weaker for longer integral time and is intensified by
shortening time. Too short integral time causes integrating hunting and may result in wavy operation.
(3) D (derivative time)
Improves stability of control by reducing overshooting of integration from expected change of the control output. Effect of compensation is weaker for
shorter derivative time and is intensified for longer time. Too long derivative time may result in oscillating operation.
0-4 heater break alarm set screen
point flashing
point flashing
point goes off to
indicate registration
key
key
key
one by one
continuing
