Micromod Micro-DCI: 53MC5000 Training Manual - Manual (Page 149)

Training Manual
F-TRAN Programming Lab
10- 3
The maximum number for each of the program types:
Control F-TRAN programs 20
Display F-TRAN programs 70
User written F-TRAN subroutines 50
10.3.4 Reverse Polish Notation:
The statements in the F-TRAN program are executed in a sequence. The sequence in
which the controller performs a calculation in a statement is dictated by the push-down
stack operation. To accomplish this, the statements in F-TRAN program are written with
a method called Reverse Polish Notation (RPN). This is a special method and is different
from the standard way of executing the calculation in a statement. To understand this,
consider the following examples:
Example 1:
Operands: A and B
Operators: Addition (+)
Standard or Algebraic notation: Calculation: A+B
Reverse Polish Notation: AB +
Example 2:
Operands: A, B and C
Operators: Multiplication (*) and Addition (+)
Standard or Algebraic notation: Calculation: A*(B+C)
Reverse Polish Notation: BC + A *
In Reverse Polish Notation, the operands are written first followed by the operator as in
the example above.