Siemens SIMATIC PG 720, Manual

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5
5-2
PG 720 Programming Device
C79000-G7076-C720-02
5.1 Opening the Unit
The device is designed for easy maintenance so that any work that is
necessary can be done quickly and at low cost.
!
Caution
The electronic components on the cards are extremely sensitive to
electrostatic discharge. Certain precautionary measures are therefore
necessary when handling such components. These measures are explained in
the guidelines for handling electrostatically sensitive devices at the end of
this manual.
All technical specifications and licences apply only to expansion functions
approved by SIEMENS.
No liability can be accepted for impairment of functions caused by the use of
devices and components of other manufacturers.
All the modules and components in the PG 720 are electrostatically sensitive.
Please read the ESD guidelines at the end of this book carefully. The
following symbol warns that electrostatically sensitive modules are present.
It is essential that the following rules are adhered to when carrying out any
work on the open unit and you should read them carefully before opening the
unit.
S
Before you disconnect the power supply cable, discharge any electrostatic
charge on your body. You can do this by touching the metal mounting
plate for the interfaces on the left panel of the unit.
S
Discharge any electrostatic charge from tools that you are using.
S
Wear a grounding wrist-strap if you are handling components.
S
Leave components and modules in their packing until you are ready to
install them.
S
Disconnect the PG 720 from its power supply and remove the battery
before plugging in or removing any modules or components.
S
Touch components and modules only on their edges. Above all, do not
touch the connecting pins and printed conductors.
S
Never operate the PG 720 with the cover open.
Prerequisites
Limitation of
Liability
Before Opening
the Unit
PG 720 Expansions