Setting The Set Point; Using On/Off Control; Setting The Sp; On/Off Control Operation - Omron CJ Series Operation Manual

Setting the Set Point

Starting DM Area Word
3-7

Setting the Set Point

3-7-1

Setting the SP

Example
Starting CIO Area Word
3-8

Using ON/OFF Control

3-8-1

ON/OFF Control Operation

Control Sensitivity
56
The starting DM Area word (m) for a Special I/O Unit is:
m = 20000 + (100 × unit number)
Set the set point (SP) in the corresponding word of the Operation Data in the
CIO words allocated to the Unit. (See the following table.)
When setting the set point, use the data format set with pin 3 of the DIP switch
on the front of the Unit. The temperature units are set on pin 2 of the DIP
switch and the default setting is 0 s or 0.0 s.
CIO word
CIO (n) Loop 1 SP (set point)
CIO (n+1) Loop 2 SP (set point)
CIO (n+10) Loop 3 SP (set point)
CIO (n+11) Loop 4 SP (set point)
To change the loop 1 set point from 0 to 200 ° C, write a value of 0200 to CIO
word n if the Unit's data format is set to BCD or write a value of 00C8 to CIO
word n if the Unit's data format is set to binary.
Note Changing the set point is not enough to start temperature control, it is also
necessary for the Stop Bit for that loop to be OFF. See 3-12 Starting and Stop-
ping Temperature Control for details.
The starting CIO Area word (n) for a Special I/O Unit is:
n = 2000 + (10 × unit number)
With ON/OFF control, you set a set point in advance. During reverse opera-
tion, the Temperature Controller will turn OFF the control output when the set
point is reached. When the control output goes OFF, the system temperature
will begin to drop and the control output will be turned ON again when the sys-
tem temperature falls below the set point. This ON/OFF operation is repeated
around the set point.
The control sensitivity setting determines how far the system temperature has
to fall below the set point before the control output is turned ON again. Also,
the control operation setting determines whether the Unit operates with for-
ward operation (cooling) or reverse operation (heating). With forward opera-
tion, the manipulated variable increases as the PV increases; with reverse
operation, the manipulated variable decreases as the PV increases.
Pin 6 of the DIP switch on the front of the Unit selects whether the Tempera-
ture Control Unit uses ON/OFF control or PID control with 2 degrees of free-
dom. The Unit will use PID control if pin 6 is OFF; it will use ON/OFF control if
pin 6 is ON. The factory setting is PID control.
In ON/OFF control, the ON and OFF switching creates a stable hysteresis
loop. The width of the hysteresis loop is called the control sensitivity.
Setting
BCD
The setting ranges depend on the input type
set with the Input Type Switch on the front of
the Unit. Refer to 2-3-5 Setting the Input Type.
Section 3-7
Setting ranges
Binary