Chapter 4 Labels; Type - Mitsubishi Electric MELSEC iQ-F Series Programming Manual

4
LABELS
Labels are variables for I/O data or internal processing, specified by a character string.
Users can create a program without considering devices or buffer memory size by using labels.
Thus, a program, where labels are used, can be reused in a system with a different module configuration easily.
When labels are used, there are some precautions on programming and functions used. For details, refer to the following.
Page 41 Precautions
4.1

Type

This manual describes the following types of label.
• Global labels
• Local labels
Global labels
Global labels are labels that can be shared by programs in a project. Global labels can be used in all the programs in a
project.
Global labels can be used in program blocks and function blocks.
When setting a global label, set the label name, class and data type, and assign a device.
■Device assignment
Devices can be assigned to global labels.
Item
Label to which no device is assigned
Label to which a device is assigned
Local labels
Local labels are labels that can be used in each POU only. Local labels that are not included in POUs cannot be used.
When setting a local label, set the label name, class, and data type.
There are other types of labels available in addition to global labels and local labels.
System labels
System labels can be shared among iQ Works-compatible products and are managed by MELSOFT
Navigator. Global labels registered as system labels can be monitored or accessed using the system labels on
GOT.
For details, refer to the following.
iQ Works Beginner's Manual
Module labels
Module labels are labels defined uniquely by each module. Module labels are automatically generated by the
engineering tool from the module used, and can be used as a global label.
For details, refer to the following.
MELSEC iQ-F FX5 CPU Module Function Block Reference
For registration of module labels, refer to the following.
GX Works3 Operating Manual
4 LABELS
32
4.1 Type
Description
• Programming without concern to devices is possible.
• Defined labels are allocated to the label area or latch label area in the device/label memory.
• If a device is to be programmed as a label referring to a device that is being used for input or output, the device can
be assigned directly.
• Defined labels are allocated to the device area in the device/label memory.