Publication 1766-RM001A-EN-P - October 2008
344
Process Control Instruction
Automatic / Manual (AM)
The auto/manual bit can be set or cleared by instructions in your ladder
program. When off (0), it specifies automatic operation. When on (1), it
specifies manual operation. In automatic operation, the instruction
controls the control variable (CV). In manual operation, the user/control
program controls the CV. During tuning, set this bit to manual.
Control Mode (CM)
Control mode, or forward-/reverse-acting, toggles the values E=SP-PV and
E=PV-SP.
Forward acting (E=PV-SP) causes the control variable to increase when
the process variable is greater than the setpoint.
Reverse acting (E=SP-PV) causes the control variable to decrease when
the process variable is greater than the setpoint.
PV in Deadband (DB)
This bit is set (1) when the process variable is within the zero-crossing
deadband range.
Tuning Parameter
Descriptions
Address
Data Format Range
Type
User Program
Access
AM - Automatic/Manual
PD10:0/AM
binary (bit)
0 or 1
control
read/write
TIP
Output limiting is also applied when in manual.
Tuning Parameter
Descriptions
Address
Data Format
Range
Type
User Program
Access
CM - Control Mode
PD10:0/CM
binary (bit)
0 or 1
control
read/write
Tuning Parameter
Descriptions
Address
Data Format
Range
Type
User Program
Access
DB - PV in Deadband
PD10:0/DB
binary (bit)
0 or 1
status
read/write
efesotomasyon.com - Allen Bradley,Rockwell,plc,servo,drive
