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Simple Application Controllers
Function Block Programming 2
2 - 1
2.
Function Block Programming
The
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Series Controller is programmed with a user-friendly method of combining special
dedicated purpose function blocks. The task is broken down into various stages which can be
represented by a number of function blocks. Function Block Programming simplifies
application representation but ensures complete process control. The program can be
developed in very simple steps but even a complex task can be represented in this way. For
ease of use, the function blocks have been preprogrammed to perform certain tasks yet offer
flexibility to be tailored to individual requirements.
Figure 1.1: Principle of Function Block Programming
I0n - Input n
O0n - Output n
OR - OR Boolean Function Block
SR - Set/Reset Function Block
OS - One Shot Function Block
The user can build a complex circuit in small easy steps by starting at the input and working
forward in a logical manner. The
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will gather and process information and provide the
necessary control for the application according to the system algorithm. Each individual
function block provides specific control parameters, accessible by the user, to tailor each pro-
gram for complete application suitability. The function blocks are connected together to form a
circuit using the Function Block Diagram (FBD.)
2.1
Block Type and the FBD base
There are seven sets of items that can be used in the function block program: Inputs, Front
Panel Keys, System Memory Bits, Logic Blocks, Function Blocks, User-defined Function
Blocks and Outputs. A brief description of each follows.
I01
OR
1 B002
One Shot
I02
I03
2
3
4
OS
B001
S
C
SR
B003
Set/Reset
O01
O02
O03
S
R
