User`s manual

535 User's Manual Chapter 7 71
Applications
NOTE: Controller capabilities depend
upon the specified hardware option.
CHAPTER 7
APPLICATIONS
The 535 controller provides a variety of user-programmable control features
and capabilities. The following topics are included in this chapter:
A. CONTROL TYPE
Software Configuration
1. Go to the CONTROL menu.
2. For the parameter ALGORITHM, select the type of 535 control:
• ON-OFF
“Crude” control similar to a household thermostat. Used primarily
on slow, stable processes where moderate deviation (cycling)
around setpoint is tolerable. Only available with SSR, SSR Drive,
and relay outputs.
•P
Proportional only control. Provides much better control than on/off.
Used on processes that are less stable or require tighter control, but
have few load variations and do not require a wide range of setpoints.
•PI
Proportional plus integral control. In addition to proportional control,
it compensates for control errors due to wide range of setpoints or
load requirements. The integral term works to eliminate offsets.
•PD
Proportional plus derivative control. In addition to proportional con-
trol, it compensates for control errors due to fast load variations.
• PID
Proportional plus integral plus derivative control. In addition to pro-
portional control, it compensates for changes in setpoint, load re-
quirements and process variations.
• PID/ON-OFF
Only available with Duplex control. First output uses the PID algo-
rithm, while second output uses on/off control.
3. For algorithms using the derivative function (D), choose the conditions for
the derivative term:
A. Control Type ......................................... 71
B. Alarms ................................................. 72
C. Duplex Control ...................................... 76
D. Slidewire Position Proportioning Control .. 81
E. Velocity Position Proportioning Control .... 82
F. Staged Outputs .................................... 83
G. Retransmission .................................... 83
H. Digital Inputs ......................................... 84
I. Remote Setpoint ................................... 86
J. Multiple Setpoints .................................. 87
K. Multiple Sets of PID Values .................... 87
L. Powerback ........................................... 88
M. Self Tune—POWERTUNE® ................. 89
N. Ramp-to-Setpoint ................................. 94
O. Input Linearization ................................. 95
P. Load Line ............................................. 97
Q. Security ............................................... 97
R. Reset Inhibition ..................................... 98
S. Process Variable Reading Correction ..... 98
T. Serial Communications ......................... 99
U. Cascade Control ................................. 100
V. Ratio Control ...................................... 103