5.0 CONFIGURATION PARAMETERS
The configuration parameters provide the latitude to define the controller’s
personality attributes
,
so that while still functioning within its designed specifications, it can perform application require-
ments with greater refinement. Typical configuration parameters are the fine tuning variables to
set the controller’s responsiveness; the indicator zero point and span; the display tag names; engi-
neering units of the process variable; and alarm limits, etc.
IT IS NOT NECESSARY TO DEFINE
ALL OF THE CONFIGURATION PARAMETERS
, as commonly used default values may not have
to be altered, certain parameter selections eliminate others, and the process application itself may
not require specific controller attributes. Although all resident in a memory database as
data-
points
, the configuration parameters are clustered into modular groups as shown in Figure 5-1.
5.1 READY TO USE CONTROL STRATEGIES
Ready to use control strategies are listed in Table 5-1. More information about these control strate-
gies is provided in their respective sections.
Table 5-1. Ready to Use Control Strategies
CS Title Section
1 Single Loop Controller 6
20 Two Loop Controller 11
41 Four Loop Controller 15
5.2 DATAPOINT TYPES
A parameter can be any one of six data types. Each data type represents a specific data format:
integers, alphanumeric text strings, etc. A database module containing multiple parameters can
have a mix of data types. The data types are defined in Table 5-2 as follows:
Table 5-2. Datapoint Types
Type Byte
Size
Format
L 1 Bit Represents a single binary bit that can have the value of 0 or 1.
B 1 Represents a positive integer with values from 0 to 255.
C 3 Represents real analog (floating point) values that have a resolution of one part
in 32,768 (15 bits) and a dynamic range of
±
10
38
.
H 5 Represents high precision analog (floating point) values that have a resolution of
one part in 2 billion (31 bits) and a dynamic range of
±
10
38
.
A 10 Represents text strings that can be 10 characters long.
F 5 Represents text strings that can be 5 characters long.
Section 5. Configuration Parameters
5-1