57
•
P Control Action
Within the proportional band, the manipulated variable is output in proportion to
the deviation between the EVT1 value and ORP value.
EVT1 Type
Description
ORP input low limit
action
If ORP value is lower than [EVT1 value – EVT1 proportional
band], EVT1 output is turned ON.
If ORP value enters within the proportional band, EVT1 output
is turned ON/OFF in EVT1 proportional cycles.
If ORP value exceeds the EVT1 value, EVT1 output is turned
OFF.
ORP input high limit
action
If ORP value is higher than [EVT1 value + EVT1 proportional
band], EVT1 output is turned ON.
If ORP value enters within the proportional band, EVT1 output
is turned ON/OFF in EVT1 proportional cycles.
If ORP value drops below the EVT1 value, EVT1 output is
turned OFF.
•
ON/OFF Control Action
EVT1 Type
Description
ORP input low limit
action
If ORP value is lower than EVT1 value, EVT1 output is turned
ON.
If ORP value exceeds the EVT1 value, EVT1 output is turned
OFF.
ORP input high limit
action
If ORP value is higher than EVT1 value, EVT1 output is turned
ON.
If ORP value drops below the EVT1 value, EVT1 output is
turned OFF.
If ON and OFF time are set in [Output ON/OFF Time when EVT1 Output ON (p.25, 26)],
and when EVT1 output is turned ON, EVT1 output is turned ON/OFF in a configured
cycle.
Timing chart of Output ON time and OFF time while in EVT1 output ON
(Fig. 9.2-2)
EVT output status can be read by the status flag (EVT1, EVT2, EVT3, EVT4 output bit)
in Serial communication (C5 option).
EVT output status, when input errors occur, differs depending on the selection in
[EVT output when input errors occur (p.50)].
• If
(Disabled) is selected, EVT output is turned OFF when input errors occur.
• If
(Enabled) is selected, EVT output is maintained when input errors occur.
OFF
ON
OFF
ON
Actual EVT1 output
EVT1 output to
which ON time
and OFF time
are set.
ON
time
ON
time
ON
time
OFF
time
OFF
time
ON time is turned
OFF, caused by the
actual EVT1 output
turning OFF.