Baldor 23H Series, Инструкция по установке и эксплуатации

Страница: 49 / 127

will adjust the motor speed or torque to force the process variable to be as close as possible to the
programmed preset setpoint.
The external command setpoint input PID control mode is used for more complex applications
having a large external disturbance that can affect the process variable. This is useful for processes
that have significant time lag between a process disturbance and the generation of a process error
signal from the process sensor. This mode uses a feedforward command to anticipate changes in
the process. This feedforward signal directly changes the motor speed or torque without having to
develop a process error signal first.
Figure 2-21 shows a block diagram of the Process Mode control system. The user must make the
determination of which technique to implement.
Figure 2-21 Simplified Process Control Feedback System Diagram
NOTE: EXB = OPTIONAL EXPANSION BOARD
2-38 INSTALLATION
∑
∑
∑
∑
PROCESS FEEDBACK
Select The Source Through
Parameter Adjustment.
Available Sources:
POTENTIOMETER
+/-10 VOLTS
+/-5 VOLTS
4 TO 20 mA
10V EXB
4 TO 20 mA EXB
3 TO 15 psi EXB
TACHOMETER EXB
SERIAL EXB
NONE=FACTORY PRESET
COMMAND SELECT
Select The Source Through
Parameter Adjustment.
Available Sources:
POTENTIOMETER = F.P.
+/-10VOLTS
+/-5VOLTS
4 TO 20 mA
10V W/EXT CL
EXB PULSE FOL
10V EXB
4 TO 20 mA EXB
3 TO 15 psi EXB
TACHOMETER EXB
SERIAL EXB
NONE
Setpoint
Command
Parameter
Closed When Process
Mode is Enabled (J1-13)
ACC/DEC
S-Curve
Profiler
Differentiator
EXB Pulse
Follower Only
s
s
Proportional
Gp
Gp
Proportional
Differential
Differential
Amp
Gd s
Gd s
Integral
Integral
Motor
Enc.
Gi
s
Gi
s
Setpoint Adjustment Limit
w/ Integral Clamp To
Max Limit Value
Existing Baldor Control System
Differentiator
–
–
+
+
+
+
“PROCESS FEEDBACK”
“PROCESS FEEDFORWARD”
MN723H-10/95 11/28/95 1:11 AM Page 50 (Black plate)