Manual

Innotech Device Network Cabling Installation Instructions
© Mass Electronics Pty Ltd 2007
Chapter 2 – Primary Networks
Page 21
2-2.3 Earth Connections
The earth connection type on HMIs and converters depends on the typical application of the device.
A potential earth dierence between main installations and remote HMIs can cause problems in the
network.
An attempt must be made to eliminate the earth potential dierences between the Net comms
and Global comms network cabling. This applies to any so or floating earth device connected to a
primary network.
The list below indicates the dierent types of earth connections.
• The GENII VIEWPORT has terminal 3 for the dedicated earth connection. It is used for the so earth
path of the comms screen terminal
• The MP01 MiniPort has terminal E for the dedicated earth connection. It is used for the so earth
path of the comms screen terminal
Where either the GENII VIEWPORT or MP01 MiniPort may have the 24V neutral earthed there is no link to the earth
terminal. Therefore a hard earth connection to the earth terminal is still required.
NOTE
• The CONV E should have the 24 V supply earthed on the secondary of the transformer as best
practice. The CONV E has a floating type screen connection
• The CONV USB and the CONV 232 are isolated or floating devices and where they have a so earth
type comms connector fitted there is no path to earth available at these devices
The following indicates how a network can be practically wired to eliminate earth potential
dierences and problems that may occur between the Net and Global networks.
1. When the HMI or converter is mounted at the end of a run, the Global can finish at the last
controller. It is suicient to run NET only from the last controller to the HMI or converter.
Figure 2-8: End of Run Mounted HMIs or Converters
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