4 PRECAUTIONS FOR USE OF SAFETY PROGRAMMABLE CONTROLLER
4.2 Precautions for Programming
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4
■Standard/safety shared label
This is a label to deliver data between safety program and standard program. The standard/safety shared label data are non-
safety data. Input data from standard remote I/O module are input as non-safety data to safety program by standard/safety
shared label, so that they cannot be used for safety control. Similarly, standard remote I/O module data output from safety
program by standard/safety shared label are non-safety data. Therefore, they cannot be used for safety control.
When a standard/safety shared label is used in a safety program, create the program so that the device operates only when
safety state is secured. For example, if there are safety devices or safety labels to check safety status using an AND circuit
such as an emergency stop switch connected to a safety remote I/O module and input data from a light curtain, combine the
safety devices and safety labels to form an AND circuit.
The following shows application examples for standard/safety shared labels.
Start processing of standard program (1) without establishing interlock with other devices. Start processing of standard
program (2) after establishing interlock with standard remote I/O module. In the following example, the standard data X100,
X101, and X102 input from standard remote I/O module is delivered to safety program with standard/safety shared label. The
safety program uses the start signal of the device "start_in" as part of an AND circuit together with the safety information
"SA\M5". Start processing of standard program (3) after establishing interlock with standard remote I/O module. Also, in the
following example, data same as safety information of safety program "SA\M5" is delivered to standard program with
standard/safety shared label. The standard program uses "safe_state" to establish an interlock. These methods are used
when desiring to start operation after completing safety check using the safety control.
For details on the described programs, refer to the following specific examples.
Page 51 SAFETY APPLICATION CONFIGURATION EXAMPLES
Standard
program (3)
Safety
program
Safety state signal
Standard
program (2)
Data link status of
the standard
remote I/O module
Standard
program (1)
Machine operation
(standard control)
Standard
output data
Standard
output data
Standard
output data
Standard input data
Standard/safety
shared label
Interlock
Interlock
Standard/safety
shared label
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