Parker 8903/DN, Technical Manual

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5
DeviceNet Communications Interface
Wiring the System
DeviceNet is a 4-wire system. Two wires convey the DeviceNet data and the remaining two
wires convey power if the product is remotely powered. Remote powering is recommended and
is necessary if the network is to remain operational between other devices when the drive is
powered down.
Cable Specification
The DeviceNet specification makes recommendations for cable type depending on whether the
cable is to serve in a trunk or a drop.
Full cable specifications are provided in the DeviceNet specification, Volume1 appendix B.
A summary is given here.
Trunk cable Drop cable
Signals wires Twisted pair, #18. Blue / white Twisted pair, #24. Blue / white
Power wires Twisted pair, #15. Black / red Twisted pair, #22. Black / red
Shield Foil / braid with drain wire (#18);
bare.
Each pair shielded separately in
aluminized mylar.
Combined pair shielded
Foil / braid with drain wire (#22);
bare.
Signal pair shielded in foil.
Overall braid shield
Internal insulation PVC insulation on power pair PVC insulation on power pair
Electrical
High speed (VP
≥
0.75), low loss,
low distortion data pair.
High speed (VP
≥
0.75), low loss, low
distortion data pair.
Characteristic
impedance of
data pair
120 Ω ± 10% 120 Ω ± 10%
Maximum Cable Lengths
The maximum cable length depends on the baud rate selected:
Data Rate Trunk Distance Drop Length
Maximum Cumulative
125kbaud 500 metres (1600
ft.)
156 metres (512 ft.)
250kbaud 200 metres (600 ft.) 3 metres (10ft) 78 metres (256 ft.)
500kbaud 100 metres (300 ft.) 39 metres (128 ft.)
Motor
Controller
Sensor Actuator
Controller
Trunk
Drops
Sensor