Rockwell Automation 1771-SDN DeviceNet Scanner Module Installation Instructions - Manual (Page 25)

Publication 1771-IN014B-EN-P - September 2001
DeviceNet Scanner Module Catalog Number 1771-SDN/C 25
•
DeviceNet 2 Scan Counter (word 17) – the scanner increments
a one-word counter whenever a scan of the DeviceNet 2 devices
is completed. The counter rolls over when it reaches its
maximum value.
•
Device Idle State Bitmap (words 18–25, 4 words for Channel 1,
four words for Channel 2) – the scanner assigns one bit to
consecutive Device Addresses. Devices on Channel 1 are
indicated by a single bit in consecutive order in words 18–21.
Devices on Channel 2 are indicated by the bits in words 22–25.
If a bit is set, it indicates that the scanner received a valid
DeviceNet idle indication from this node. A device in idle mode
does not return updated I/O data to the scanner because the
device is not in its run mode.
•
Node Address/Status Indicator (word 26) –- Channel 1 and
Channel 2 node address and scanner diagnostic information is
copied to the low and high bytes of Word 26, respectively.
The descriptions of these codes are listed on page 36.
•
25 words of pad data (zeroes, words 27–51), to complete the
table for a total of 52 words.
Configure Your Module for
the DeviceNet Network To operate your 1771-SDN Scanner Module, you must configure the
two tables listed below, using RSNetworx for DeviceNet software. For
additional information, refer to your RSNetworx documentation or
online help and your 1771-SDN Scanner Configuration Manual
(publication number 1771-UM118C-EN-P).
Configure this table: To:
Scanner Configuration Table
Control how the scanner gathers DeviceNet messages.
The information you configure for this table includes:
• frequency of background poll messages on each
DeviceNet channel
• DeviceNet port disable/enable
Scan List Table
Use the information gathered from the scan list table to
map the I/O data between the scanner’s I/O data table
and DeviceNet nodes. A device must have a
configuration table entry in the scanner’s database
before its I/O messages are mapped to the PLC. The
information you configure for this table includes:
• the size of data in each node’s DeviceNet messages
• location of a device’s data in the data tables that are
transferred to and from the PLC