User`s manual

535 User's Manual Chapter 7 77
Applications
horizontal axis. Draw a vertical line at that point. At the intersection of this vertical
line and the respective output line, draw a horizontal line. The physical output
is the value where this horizontal line intersects the respective axis.
The illustrations assumes a manual reset/load line term of 50%. Therefore, at
zero error (process variable equals setpoint) the PID output is 50%.
Duplex with reverse and direct acting outputs
A reverse acting output 1 and a direct acting output 2 with: no offset, no restrictive
outputs limits, and a neutral relative gain with PID control.
Duplex with direct and reverse acting outputs
A reverse acting output 1 and a direct acting output 2 with: no offset, no restrictive
output limits, and a neutral relative gain with PID control.
Figure 7.2
Duplex with Reverse and Direct
Acting Outputs
PID OUTPUT
100%
PARAMETER SETTINGS
ACTION:1 = REVERSE
ACTION:2 = DIRECT
PID OFST.:1 = 0
PID OFST.:2 = 0
LOW OUT = 0
HIGH OUT = 100
REL. GAIN = 1.0
100%
50%100% 0%
Out 1
Out 2
Out 1
Out 2
0%
0%
PID OUTPUT
PARAMETER SETTINGS
ACTION:1 = DIRECT
ACTION:2 = REVERSE
PID OFST.:1 = 0
PID OFST.:2 = 0
LOW OUT = 0
HIGH OUT = 100
REL. GAIN = 1.0
100%
100%
50%100% 0%
Out 1
(Heat)
Out 2
(Cool)
0%
0%
Out 2
Out 1
Out 2
Out 1
Figure 7.3
Duplex with Direct and Reverse
Acting Outputs