PL-565
Accumass BW500
Page 95
P
ID Control
PID Control
The PID control algorithm in the BW500 is designed specifically to work for feed rate
control applications. It is based on motor control type algorithms and includes several
anti-wind up provisions.
One way to prevent wind up is to monitor the input speed frequency from the
weighfeeder. If the input frequency drops below 5 Hz, the PID control output freezes
at its current value. Otherwise, the output winds up to 100% if the feeder is shut off
while there is still a set point greater than zero. When the feeder is turned back on,
there would be a surge of product flow until the system regains stability. With anti-
wind up, the feeder can be stopped and started with minimal disruption to the
controlled flow rate.
In order for the BW500 to operate as a controller, the following must be addressed:
✔
hardware
✔
connections
✔
setup and tuning
✔
programming
Hardware
In order for the BW500 to operate as a controller, the optional mA I/O board must be
installed. Refer to Installation on page 13.
Connections
Connections to process instruments, in addition to standard operating connections,
must be made.
Refer to Installation on page 13, specifically:
Relay Output on page 25, for relay connections
mA I/O board on page 15, for mA input and output connections
Auxiliary Inputs on page 23, for optional remote control
Connect the BW500 as either a:
1.
setpoint controller – load control
2.
setpoint controller – rate control
3.
setpoint controller – rate and load control
4.
setpoint controller – external process variable with or without rate and load control
PID loop
mA output
terminals
mA input
terminal
(mA I/O)
(mA I/O)
1
2
1 & 2
1
5 & 6
2
3
3 & 4
2
7 & 8
Summary of Contents for ACCUMASS BW500
Page 1: ...ACCUMASS BW500 Instruction Manual PL 565 January 2001 CCUMASS BW500 33455650 Rev 1 2...
Page 6: ...Page 6 Accumass BW500 PL 565...
Page 12: ...Page 12 Accumass BW500 PL 565 Specifications...
Page 28: ...Page 28 Accumass BW500 PL 565 Installation...
Page 88: ...Page 88 Accumass BW500 PL 565 Parameters...
Page 94: ...Page 94 Accumass BW500 PL 565 Operation...
Page 106: ...Page 106 Accumass BW500 PL 565 PID Control...
Page 110: ...Page 110 Accumass BW500 PL 565 Batching...
Page 112: ...Page 112 Accumass BW500 PL 565 Certification...