Allen-Bradley 1440-SDM02-01RA, User Manual, Page: 55 / 168

Rockwell Automation Publication 1440-UM001D-EN-P - September 2016 55
Install the XM-124 Standard Dynamic Measurement Module Chapter 1
Switch 1 - DIP Switch Enable (0) / Disable (1)
If the module’s DeviceNet address is set in firmware, then the DIP switch must
be disabled.
Switch 2 - Normal/Legacy Mode
In most cases, the module must be left in Normal (default) mode. However, if
the module is used to replace an existing XM-12X module, and DeviceNet V+
is not wired, then the mode must be set to Legacy.
Switches 3 and 4 - Set DeviceNet Communication Rate
These switches are ignored if switch #1 is in the on (1) position (switch
disabled). Use these switches to set the communication rate.
IMPORTANT When earlier XM modules are included on a network, it is left up to you to
confirm that no nodes exist with the same MAC ID and that only one Client
device is configured to access the same device using the Predefined Master/
Slave Connection Set. Bus errors can occur if either of these conditions
exists.
IMPORTANT When DIP switch #2 is set to Legacy mode (OFF), the XM 124 continues to
communicate even when DNet V+ is not present. If connections are
established when DNet V+ is restored, other XM modules do not perform a
Duplicate MAC ID check. Consequently if an address conflict exists it is not
always detected and erroneous data or unexpected behaviors including
potentially a BUS OFF condition can result.
IMPORTANT When DIP switch #2 is set to Normal mode (ON), the XM-124 module
behaves per the DeviceNet standard and does not communicate when
power is not present on DeviceNet V+. At any time that power is detected
on DeviceNet V+ the XM-124 module performs a Duplicate MAC ID check
and, in the event that a module with a duplicate address is detected,
terminates all communication.
TIP Legacy mode is consistent with how previous XM modules, including the
XM-12x modules, behaved with respect to the presence of power-on
DeviceNet V+. However, in both Legacy and Normal mode, an XM-124
module performs a Duplicate MAC ID check when the module detects power
that is applied to DeviceNet V+. This check is a change in behavior from
earlier XM modules.