Micromod Micro-DCI: 53MC5000 Multi-Loop Process Controller CUSTOMIZATION GUIDE - Manual (Page 12)

2.4.2 Operands
When writing programs for the Controller it is important to remember that the permissible operands
include all the various elements described in the DATA BASE.
DATA TYPES:
Lxxx
Bxxx
Cxxx
Hxxx
Axxx
Fxxx
In addition to the L, B, C, H, F and A type data values, it is permissible to use literal values in a pro-
gram. There are three types of literals allowed. String literals contain up to 10 characters sur-
rounded by double quotes, i.e., "STRING" equivalent to A data types. Integer literals are numeric
integers between 0 and 255. These are equivalent to B data types. Numeric literals are numbers
which contain a decimal point. These are equivalent to C data types. Numeric or Integer literals
may be used in mathematical computations, comparisons, etc., as their corresponding data type
would be used.
Standard Precision Numbers are used in the Controller programs for mathematical computations
and assigned as required for signal conversion and/or data handling. Typically, these numbers rep-
resent actual system operating parameters, scaling or span factors, debias or rebias, and com-
puted variables.
Standard Precision Numbers "C" are stored in random access memory and can be assigned 10-
digit (4 significant digit) floating point values between the limits of -999900000 to +9999000000 (mi-
nus sign counts as 1 digit).This limitation is the result of the readout. However, many of the
constants are preassigned for use in subroutines, as analog outputs, and for analog input span and
zero settings.
Similarly, many of the "H" data types(high precision) have hardware assignments;i.e., analog in-
puts, totals counters, pulse counters, etc. For example, ANI0 will be computed and stored in H00 in
the engineering unit assigned.
2.4.3 Operators
Table 1 lists the operators that are commonly used in the MICRO-DCI instrument source programs.
The respective operator symbols represent mathematical or logical functions and are assigned to
groups according to the type of data represented by the operand. When writing F-TRAN state-
ments, certain operators are valid functions only when they are used in the proper context (e.g.,
logic bits cannot be multiplied and floating point numbers cannot be used in AND, OR and XOR
logic statements without data transformation). F-TRAN operators and their respective functions are
discussed throughout the remainder of this section.
MODULAR CONTROLLER CUSTOMIZATION GUIDE
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