Installation manual
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Examine the System Design of the Installation
Walk the network if possible to determine the actual layout. ( Make a sketch of the network )
Check number of nodes
Check cumulative drop length
Check individual drop lengths
Check branched drop length
Check total trunk length, including long drop near the ends
Check the termination location and measure the terminators
Check the power supply cable length and gauge
Check for one, and only one, earth ground of the V- and shield
Break the combination shield/V- connection to frame ground and verify >1.0 Mohm
to frame ground
Check for one and only one V- to shield connection
Break the shield/V- connection at the power supply and verify >1.0 Mohm shield to
V- with 24VDC off
Check for shorts of CAN- and/or CAN+ to shield or V- verify with an OHM meter
Check the length and gauge of the earth ground connection
Check total power load and its distribution points
Check the Power
Check trunk and drop current limits
Check type (size and length) of cable bringing power into the trunk
Measure the 24V supply at the middle and ends of the network
Consider spot checking the power for noise with an oscilloscope
It is recommended but not required that the 24 VDC Network Power for DeviceNet
should be used for the DeviceNet network only to aid in eliminating noise issues.
Check the Wiring
Check lead dress in junction boxes
Check that connectors are screwed together tightly
Check that glands are screwed tightly
Check for foreign material (electrical tape, RTV, etc.) in glands
Check that nodes are not touching extremely hot or cold surfaces
Check that cables are kept a few inches away from power wiring
Check that cables are not draped on electric motors, relays, contactors or solenoids
Check that cables are not constrained so as to place excessive tension on connectors
Wiggle connectors to provoke intermittent failures
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