P-NET Wiring
P-NET bus cable
Cable connection to the terminals depends of the cable type used:
– 1 x twisted pair: the shield is connected to the ‘S’ terminal.
– 1.5 x twisted pair (3 wire cable): the 3’Th wire is connected to the ‘S’ terminal. The cable shield is ending close to the terminals.
– 2 x twisted pair: the second pair is connected to the ‘S’ terminal. The cable shield is ending close to the terminals.
It is recommended to use the 2 x twisted pair or 1.5 x twisted pair cable type.
This offers the best noise immunity and the most convenient installation.
Connecting using a 2 x twisted pair cable
When using bus cables with 2 x twisted pairs, the pair interconnecting ‘S’ terminals must be connected to ground in one point only. This avoids the ‘S’ reference potential to be free floating
Connecting using a 1.5 x twisted pair cable
When using bus cables with 1.5 x twisted pairs (3 twisted wires), the wire interconnecting ‘S’ terminals must be connected to ground in one point only. This avoids the ‘S’ reference potential to be free floating.
Connecting using a 1 x twisted pair cable
The cable connects the ‘A’,’B’ and ‘S’ terminals of each device.
The connection from one unit to the next unit is performed by connecting ‘A’ to ‘A’, ‘B’ to ‘B’ and ‘S’ to ‘S’
Depending of the device type one or two set of A/B/S terminals exists. With one set of terminals the incoming and outgoing wires must be connected to the same terminal, with two terminals sets the terminals are internally connected and one terminal is available for each wire.
The twisted pair of wires in the cable is normally colour coded. Use one colour for all ‘A’ terminals and the other colour for ‘B’ terminals. It is very important to use the same colour throughout the installation to avoid improper operation.
One set of terminals:
Two sets of terminals:
