Rockwell Automation 1336T Function Block Prog. Manual, Series A/B - Manual (Page 63)

Chapter 4
4–1
1336 FORCE — 5.9 August 1995
Function Block Library
Detailed in this chapter are the (28) function blocks that make up the
PLC Comm Board function block set.
Each function block is a firmware subroutine stored in PLC Comm
Board Memory. Each type of function block has a unique Block type
number that identifies the functionality and the nodes that are
associated with the block. Function blocks can be linked together to
perform the same functions as equivalent analog or digital circuits.
Function blocks are executed in the order in which they are entered
in the execution list. Each function block type can be used any
number of times.
For each function block shown, the value of an I/O node will be one
of the following:
1. A signed decimal integer with a value range of
±
32767.
2. An unsigned decimal integer with a value range of 0 – 65535.
3. A logical value where 0 = False and any non-zero value = True.
Important: The use of integer math causes the truncation of any
fractional remainder resulting from a divide operation.
In addition, nodes used for input may be either linkable or
non-linkable.
4. Linkable input nodes are indicated by a in the function block
diagram.
5. Non–linkable input nodes are indicated by a in the function
block diagram.
6. The nodes used for output are not linkable and are indicated by a
in the function block diagram. However, you can use output
nodes to provide data for inputs to other function blocks or to
drive linear parameters.
When you connect function blocks, you need to be careful. Linkable
inputs can get data from any function block node or linear parameter,
regardless of its data type. As an example, you could link a signed
decimal output to a logical input. The characteristics of the
destination node determine how the input value will be interpreted.
In the case where a signed decimal output is linked to a logical input,
the value would be interpreted as a true value unless the source value
(such as a velocity or position feedback) passed through zero.
Chapter Objectives
Function Block Overview