Rockwell Automation 1769-ADN Compact I/O DeviceNet Adapter - Manual (Page 7)

Compact I/O 1769-ADN DeviceNet Adapter 7
Rockwell Automation Publication 1769-IN001C-EN-P - February 2013
System Configurations
Configuration Rules
• The adapter must be the first and left-most module in the system (the first module of
Bank 1). Refer to page
9 for an example configuration.
• The adapter can communicate with up to 30 modules in a system.
• An end cap/terminator must be on the last I/O bank.
• Each bank of I/O must have its own power supply.
• A bank of I/O can have a maximum of 16 modules with a maximum of eight on either
side of the power supply, depending upon module loading on the supply.
• A 1769 I/O power supply has limits in the amount of +5V dc and +24V dc current it
can supply to the modules in its I/O bank. These limits depend on the catalog number
(for example, 1769-PA2) of the supply. A bank of modules should not exceed the current
limits of the I/O bank power supply. Refer to the Compact 1769 Expansion I/O Power
Supplies Installation Instructions, publication
1769-IN028 .
• The maximum amount of current the system supports in one direction (either side of the
power supply) is: 2A @ 5V dc, 1A @ 24V dc.
• If another bank of I/O is required due to module requirements or I/O loading, you can
use a cable to link them together. You can have a maximum of three banks of I/O
connected with up to two communication cables.
• Each module type has its own distance rating (the number of modules from the power
supply). Each module must be within this rating for its type.
• The Series B adapter has a distance rating of five, therefore the Series B adapter must be
within five modules of the power supply.
• The Series B adapter supports reading a maximum of 163-251 words (326-502 bytes) of
input data distributed across all the modules, depending on the number of modules
present in the system
Use the following equation to calculate the maximum number of input words:
Maximum Input Words = 256 - [(Number of Modules + 1) x 2 + Number of
Output-Only Modules + 1]
Where the “Number of Modules” is the total number of modules (input and output)
in the system, and the “Number of Output Only Modules” is the number of output
modules configured to have 0 words of input data.
The maximum number of input words is distributed across all of the input modules.
• The Series B adapter supports a maximum of 196-254 words (392-508 bytes) of output
data distributed across all of the modules, depending on the number of modules present
in the system.
Use the following equation to calculate the maximum number of output words:
Maximum Output Words = 256 - [(Number of Output Modules) x 2]