System planning, Protecting the circuit board from contamination – Rockwell Automation 1769-SDN Compact I/O DeviceNet Scanner Module User Manual User Manual
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Publication 1769-UM009E-EN-P - August 2009
Chapter 3 Installation and Wiring
Protecting the Circuit Board from Contamination
The printed circuit boards of the modules must be protected from dirt, oil,
moisture, and other airborne contaminants. We recommend installing the
system in an enclosure suitable for the environment to protect these boards.
The interior of the enclosure should be kept clean and the enclosure door
should be kept closed whenever possible.
System Planning
Consider the following when planning your system:
• The scanner module can communicate with up to 63 DeviceNet devices.
• The scanner, as a master, can own up to 63 slave I/O nodes.
• The scanner module can simultaneously be a master and a slave owned
by another DeviceNet master.
• A 1769-ECR right end cap or 1769-ECL left end cap is required to
terminate the end of the Compact I/O bus.
• Each bank of Compact I/O modules must have its own power supply.
A MicroLogix 1500 controller acts as the power supply for modules
directly connected to it.
• A Compact I/O power supply, or MicroLogix 1500 base unit, has limits
on the amount of +5V DC and +24V DC current it can supply to
modules in its I/O bank.
These limits depend on the catalog number of the power supply, for
example, 1769-PA2. A bank of modules must not exceed the current
limits of the I/O bank power supply or MicroLogix 1500 base unit.
1769-IN028
1764-UM001
.
• The scanner module has a distance rating of four, therefore, the scanner
module must be within four modules of the I/O bank’s power supply.
• Determine the DeviceNet communication rate, based on standard
DeviceNet considerations.
• Consider the number of words of I/O data the host controller supports.
DNET-UM072
.