1756-CNB – ALLEN BRADLEY
Use of the Network Access Port (NAP)
Do not connect any device to the network access port (NAP) of
a 1756-CNB/D/E or -CNBR/D/E module in a redundant chassis.
• If you connect a device to the NAP of a CNB module in a
redundant chassis, a switchover will fail to occur if the
CNB module is disconnected from the network. While
the CNB module is disconnected from the network, the
controller will be unable to control any I/O devices
through that CNB module.
• If you connect a workstation to the NAP of a CNB
module in a redundant chassis, the workstation will be
unable to go online after a switchover.
To connect a device to a ControlNet network via a NAP, use a
NAP that is outside of a redundant chassis.













