Table of Contents
Advertisement
VisuNet EX2 GMP RM/PC 3700 Series
Installation and Commissioning
3
Installation and Commissioning
Observe laws, standards, and directives applicable to the intended use and the operation
location. Observe Directive 1999/92/EC in relation to hazardous areas.
Preparation
3.1
Unpacking the unit
1. Check that all package contents are present and undamaged.
If anything is damaged, inform the shipper and contact the supplier.
2. Check that all items are present and correct based on your order and the shipping
documents.
If you have any questions, please contact Pepperl+Fuchs.
3. Keep the original packing material in case you need to store or ship the unit at a later time.
3.2
Shielding of data cables
Shielding concept
Shielded cables improve signal quality and reduce interference and radiation of
electromagnetic fields.
Thus Pepperl+Fuchs recommends to use shielded data cables (RS232, USB, Ehternet). To
ensure optimum signal quality the shield must be connected and grounded permanently.
The following 3 shielding concepts exist:
1. The shield is connected and grounded to both ends. Therefor electromagnetic interferenc-
es are reduced optimal. However, there is a risk that current loops with high compensating
currents occur. If the values of the compensating currents are to high, saftey-related prob-
lems will appear.
2. The shield is connected to the VisuNet on one side and is capacitive grounded in the safe
area. Electromagnetic interferences are clearly reduced. Current loops with high compen-
sating currents are prevented.
For this concept use a capacitor (approx. 10 nF) with fixed dielectric (ceramic) and a test
voltage > 1500 V in the safe area.
3. The shield is connected and grounded to one end. Electromagnetic interferences are re-
duced. Currents loops with high compensating currents are prevented.
Note!
Consider the equipotential bonding system, before you choose a shielding concept!
Warning!
To prevent spark formation, insulate the shield carefully, if you don't connect the shield to
VisuNet.
Example 1
If a low-impedance equipotential bonding system (building grounding system) is effective
under all operating conditions, connect and ground the shield at both ends (shielding concept
1). Consider, that transients caused by switching on/off machines cannot be statically
measured.
Example 2
If there is no equipotential bonding system, choose shielding concept 2 or 3.
This applies also to poor equipotential bonding systems that haven't got a good low-impedance
and to equipotential bonding systems that have a high noise voltage.
44
Advertisement
Table of Contents
