Micromod Micro-DCI: 53MC5000 Multi-Loop Process Controller CUSTOMIZATION GUIDE - Manual (Page 10)

these values are double and standard character sets (B09 = 0,1) are mapped to large character
sets. The DFC atom is forced to active prior to each execution of the display F-TRAN program. To
write display F-TRAN for the HiRes display DFC should be set to one at the beginning of the pro-
gram.
2.2.3 Subroutines
Up to 50 user written subroutines can be stored in the controller for use by both Control F-TRAN
and Display F-TRAN. A subroutine is written just like a regular program except it must include a
"Return" statement ("R") just before the "End" statement ("E"). When a subroutine is loaded, the
programmer assigns it a subroutine number in the range 200 - 255. F-TRAN programs can then
call the subroutine by using a "G" statement. For example, G240 will cause subroutine 240 to run.
Subroutines can use any of the statement type listed in the following sections. Subroutines which
use the Display Statements should only be called from Display F-TRAN programs.
2.3 Definition of Terms
The following terms are used in the discussion of the programming language.
data base — The entire group of data items that can be used in a
source program. Such data may be assigned by direct
configuration, computed by the program, or set by a
hardware function or condition.
expression — A valid series of operands and operators which evaluate
to a single value.
operand — A data element used in a program. An operand may be a
measured value, a fixed parameter, or the result of a computation.
operator — A symbol which represents an operation to be performed
on one or more operands.
statement — A meaningful expression or generalized instruction in a
source language that instructs the computer to perform
some sequence of operations.
2.4 The F-TRAN Language
2.4.1 General Discussion
Tables 1 list the operators that are commonly used in the Controller programs. The respective op-
erator symbols represent mathematical or logical functions and are assigned to groups according
to the type of data represented by the operand. Therefore, certain operator symbols are valid func-
tions only when they are used in the proper context; e.g., logic bits cannot be multiplied and data
representing computed analog values cannot be used in AND, OR and XOR logic statements with-
out data transformation to bit level logic.
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