Allen-Bradley GuardPLC 1753, Safety Reference Manual

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Publication 1753-RM002C-EN-P - September 2008 91
Technical Safety for the Application Program Chapter 8
Procedure for Locking the PES
(1)
Locking the PES means locking functions and access from the user
during operation to prevent manipulation of the application program.
The extent of disabling actions depends on the safety requirements for
the particular application of the PES. Consult the approving board in
charge of site acceptance for help in determining the safety
requirements.
Follow these procedure to lock the PES.
1. The following attribute values must be set in the controller
before compilation:
2. After loading and starting, you can modify the following
switches in the controller in the following sequence.
a. Start / Restart allowed to FALSE, and
Loading allowed to FALSE.
b. Main Enable to FALSE
.
(1)
The only distributed I/O module that can be locked is the 1753-IB20XOB8.
Functions to Lock
Attribute Value
Main Enable True
Autostart True/False
Start/Restart allowed True
Forcing allowed False (application-dependent)
Loading allowed True
Test Mode allowed False
Stop on Force Timeout True (application-dependent)
ATTENTION
to
The following switches can be set at other values only
upon consultation with the approving board:
Force Enable to TRUE
Stop on Force Timeout to TRUE/FALSE
Start / Restart allowed to TRUE
Autostart to TRUE
ATTENTION
The Test Mode switch must never be set to TRUE for
safety operation.
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