T-Connectors; Terminal Resistances - ProMinent DULCOMARIN 3 Compact Assembly And Operating Instructions Manual

Assembly and installation

6.4.2 T-connectors

6.4.3 Terminal resistances

Summary
62
that the threaded connectors are not damaged. In environments
with aggressive chemicals, the cables and plug connectors may be
discoloured. This has no impact on functionality assuming that the
components are correctly screw-connected. The discolouration is
simply optical in nature.
Various components are available for installing the CAN system
bus:
pre-assembled M12 cables of various lengths
n
installation cables without plugs, sold by the metre (Li02YSCY)
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M12 T-connectors
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M12 terminating resistances (plug & coupling)
n
Do not connect T-connectors directly
T-connectors must not be connected directly with
an end device. There must always be a CAN con‐
necting cable between a T-connector and end
device.
T-connectors are used to connect individual end devices to the
CAN backbone. The T-connectors are inserted in the backbone
and the end device is connected using a CAN cable with a length
of no more than 2 m. T-connectors cannot be strung together.
However, the number of T-connectors directly connected to one
another should not exceed 5 for reasons of mechanical stability. If
T-connectors are strung together, ensure that they have sufficient
mechanical strength.
The CAN bus is a differential fieldbus. A CAN terminal resistance
must be fitted at both ends of the CAN backbone. Terminal resis‐
tances come in a male and female version. Generally speaking, a
male terminal resistance is needed at one end of the backbone
and a female one at the other end. You should avoid using more
than two terminal resistances in a CAN network. Terminal resis‐
tances are fitted either directly at the end of a cable or on a T-con‐
nector.
Summary:
Maximum elongation of the CAN backbone: 400 m.
n
Only tighten threaded connectors by hand and ensure that the
n
threaded connector is complete and watertight.
Never connect T-connectors directly to an end device.
n
Branching cables to the end devices should be as short as
n
possible, maximum 2 m.
If producing islands, a maximum of four end devices should be
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connected to the backbone via a branching cable.
If using M12 plug connectors provided by the customer, ensure
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the correct pin coding. The end devices may be damaged if the
polarity is reversed.
It is essential that the braid is connected electrically to the plug
n
to ensure the function.