Programming Restrictions - Omron CX-PROGRAMMER V8.1 Operation Manual

Programming Restrictions

2-4-3 Programming Restrictions
Restrictions in Locating Function Block Instances
No Branches to the Left of
the Instance
Only One Instance per
Rung
No Function Block
Connections
Downloading in Task
Units
Programming
Console Displays
Online Editing
Restrictions
54
Branches are not allowed on the left side of the instance. Branches are
allowed on the right side.
Incorrect
FB
Instruction
A program rung cannot have more than one instance.
Incorrect
FB
FB
A function block's input cannot be connected to another function block's out-
put. In this case, a variable must be registered to transfer the execution status
from the first function block's output to the second function blocks input.
0.0
FB1
FB2
EN
XIN1
XOUT
D100
XIN2
Tasks including function blocks cannot be downloaded in task units, but
uploading is possible.
When a user program created with the CX-Programmer is downloaded to the
CPU Unit and read by a Programming Console, the instances will all be dis-
played as question marks. (The instance names will not be displayed.)
The following online editing operations cannot be performed on the user pro-
gram in the CPU Unit.
• Changing or deleting function block definitions (variable table or algo-
rithm)
• Inserting instances or changing instance names
Note The instance's I/O parameters can be changed, instances can be
deleted, and instructions outside of an instance can be changed.
Correct
FB
Correct
FB
0.0
FB1
EN
D3000
XOUT
0.0
FB2
EN
D3000
XIN1
D100
XIN2
Section 2-4
Instruction
Temporary variables
transfer the value from
FB1 to FB2.