535-PROF User's Manual
Chapter 7
93
Applications
PID OUTPUT
PARAMETER SETTINGS
ACTION:1 = REVERSE
ACTION:2 = DIRECT
PID OFST.:1 = 0
PID OFST.:2 = 0
LOW OUT = 0
HIGH OUT = 100
REL. GAIN
❶
= 2.0
REL. GAIN
❷
= 1.0
REL. GAIN
❸
= 0.5
100%
100%
50%
100%
0%
Out 1
(Heat)
Out 2
(Cool)
Out 1
0%
0%
50%
❶
25%
Out 2
❸
❷
PID OUTPUT
PARAMETER SETTINGS
ACTION:1 = REVERSE
ACTION:2 = DIRECT
PID OFST.:1 = – VALUE
PID OFST.:2 = + VALUE
LOW OUT = 10%
HIGH OUT = 85%
REL. GAIN = 1.0
100%
100%
50%
100%
0%
Out 1
(Heat)
Out 2
(Cool)
Out 1
Out 2
0%
0%
10%
85%
Duplex with overlapping outputs and output limits
A reverse acting output 1 and a direct acting output 2 with: a negative offset for
output 1, a positive offset for output 2, and restrictive high and low output limits
with PID control.
This combination of offsets results in an overlap where both outputs are active
simultaneously when the PID output is around 50%.
The output limits are applied directly to the PID output. This in turn limits the
actual output values. In this example, the high output maximum limits the
maximum value for output 1, while the low output minimum limits the maximum
value for output 2. The value the actual outputs are limited to depends on offset
settings, control action and relative gain setting with PID control.
Duplex with various relative gain settings
A reverse acting output 1 and a direct acting output 2 with: various relative gain
settings (assume no offset or restrictive outputs) with PID control.
Figure 7.7
Duplex with overlapping outputs and
output limits
Figure 7.8
Duplex with various relative gain
settings
