Two-Position Control - Mitsubishi Electric MELSEC FX Series User Manual

FX -4LC User's Manual
3U
6.5

Two-position Control

When the proportional band (P) or heating proportional band (P) value is set to "0", the 4LC performs
two-position control.
In two-position control, the control output (MV) is set to ON when the measured value (PV) is larger than the
set value (SV) or OFF when the measured value (PV) is smaller than the set value (SV).
When the adjustment sensitivity (dead zone) is set, repetitious turning ON/OFF of the output around the set
value (SV) can be prevented.
However, if the adjustment sensitivity (dead zone) is set to a large value, upward/downward fluctuation
becomes large accordingly. If the adjustment sensitivity (dead zone) is set to a small value, chattering may be
caused by small oscillations of measured values (PV).
Select control mode "0" to "7" for performing two-position control.
Operation
Set value (SV)
Control output (MV) ON OFF
Associated buffer memory
BFM No.
CH1 CH2 CH3 CH4
#9 #10 #11
#13 #14 #15
#48 #88 #128 #168 Set value (SV)
#58 #98 #138 #178 Proportional band (P)/Heating proportional band (P)
#69 #109 #149 #189 Adjustment sensitivity (dead zone) setting
#240 #241
40
ON
Control output value (MV) monitor/
#12
Heating control output value (MV) monitor
#16 Cooling control output value (MV) monitor
Control mode switch
→ For details on the control mode switch, refer to Section 6.2.
Adjustment sensitivity (dead zone)
The adjustment sensitivity (dead zone) is
equally given to the upper portion and the
lower portion of the set value (SV).
OFF
Time
Description
6 Introduction of Functions
6.5 Two-position Control
Reference
Subsection 8.2.4
Subsection 8.2.5
Subsection 8.2.15
Subsection 8.2.22
Subsection 8.2.23
Subsection 8.2.62