Use sequential auto addressing – Rockwell Automation 1734-XXXX POINT I/O Digital and Analog Modules and POINTBlock I/O Modules User Manual

Page 198

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Rockwell Automation Publication 1734-UM001E-EN-P - July 2013

206 Configure POINT I/O Modules for DeviceNet Networks

device has been commissioned and attached to a network, you can use the
RSNetWorx for DeviceNet node commissioning tool to edit the node address
and data rate that were set previously.

Exercise caution while editing node addresses when on a network. When you
apply a new node address, it immediately overwrites the node address data in the
device currently specified. If you decide to reassign node addresses, you should
first determine the order in which this needs to be done so that all the devices still
have unique node addresses when you finish.

For example, if two of the devices on your network are a photoelectric sensor and
a hand controller and you accidentally change the node address of the hand
controller to be the same as that of the photoelectric sensor, then the
photoelectric sensor no longer has a unique address. This means it is not able to
provide data to the scanner. If you cannot access a device, because you have used
its node address for another device, you have to remove it from the network,
recommission it, then reinstall it on the network.

Use Sequential Auto Addressing

Sequential Auto Addressing (SAA) reassigns the node address of every module to
the right of the one you select on the POINTBus network. Each module changes
its node address to one greater than its neighbor.

When this command is set, each module to the right gets a new address one
greater than its neighbor. The addressing ripples through a line of POINT I/O
modules, assigning a node number to each module installed in a mounting base
on the same POINTBus network.

Follow these steps to Auto Address a line of POINT I/O modules.

1. Set the address of the first module you want to address.
2. Set the Auto Address command to Sequential Address.

All modules in line reset with new sequential addresses.

ATTENTION: Do not change the data rate of devices while they
are connected to a network. Erratic operation may result. We
recommend that if you need to change the data rate of a device,
you should remove it from the network, establish a point-to-point
connection between the PC, which hosts the RSNetWorx for
DeviceNet software, and the target device, recommission it, and
then, reconnect it to the network.

IMPORTANT

Make sure the node address of the selected module is the desired
value before issuing the SAA command.

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