34 SAFETY DEVICES, SAFETY LABELS, AND CONSTANTS
34.4 Safety Label
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34.4 Safety Label
A label used in safety programs is called a safety label. Information not described in this section is same as that of standard
labels. ( Page 372 LABELS)
Safety label types
There are three safety label types. Only the following labels can be used in safety programs.
• Safety global label
*1
• Standard/safety shared label
*2
• Safety local label
*1 Safety devices can be assigned.
*2 Can be used in standard programs and standard function blocks as well.
• An initial value cannot be set for safety labels and standard/safety shared labels.
• Only safety labels can be used as alias source of a safety label. Only standard/safety shared labels can be
used as alias source of a standard/safety shared label. Safety labels and standard/safety shared labels
cannot be used as alias source of a standard label. ( GX Works3 Operating Manual)
How to use standard/safety shared labels
A standard/safety shared label is used to pass device data from a safety program to a standard program, and vice versa.
When a standard/safety shared label is used in a safety program as shown in the examples below, the program needs to be
created so that the safety state is secured.
■To restart safety control by the command from the GOT
Standard control
Standard control
Safety control
Safety control
Used in a safety control.Transfer data.
Standard/safety
shared label
Standard/safety
shared label
Standard program
Perform write to turn on M0 from GOT.
Safety program
Create a program in which the safety control processing is set in
a safety program and the standard/safety shared label is used.
Restart processing
SM400 M0
[ SET GOT_OPE ]
GOT_OPE SA\M0
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