ProSoft Technology MVI56E-MCMR - Manual (Page 166)

Reference MVI56E-MCMR ♦ ControlLogix Platform
User Manual Modbus Communication Module with Reduced Data Block
Page 166 of 225 ProSoft Technology, Inc.
May 13, 2014
Warm Boot Block (9998)
The Warm Boot special function is used to restart the module application from
within processor logic. This allows the module to be restarted without removing it
from the chassis or removing power from the chassis. Restarting or "rebooting"
the module will momentarily interrupt normal module operation, such as Modbus
polling and backplane data transfers. It will also clear and reset all module
diagnostic counters and user database memory.
This special function is one of the few that is sent in the Output Image Write Data
block instead of a MSG instruction. Therefore, the effect of triggering a Warm
Boot is almost immediate.
If you follow the sample ladder logic or AOI, the block identification code 9998 for
the Warm Boot special function is embedded in the logic that formulates the
Write Data block to be sent to the module in the Output Image. You can activate
this special block logic by setting the controller tag,
MCMR.CONTROL.W
ARM B OOT , to a value of 1. This will force an immediate
module reboot.
The following table describes the format of the Warm Boot data block
constructed by the processor.
Block Request from Processor to Module
Word Offset Description Length
0 9998 1
1 to 41 Spare 41
Warm Boot and Cold Boot special functions are almost identical in what they do
to reboot the module. The main difference between the two is that the Warm
Boot restarts the internal firmware application without interrupting backplane
power to the module. Therefore, a Warm Boot will complete and the module will
return to normal operation a few seconds faster than when a Cold Boot is used.
However, if the module is not operating correctly and a Warm Boot does not
completely restore normal operation, a Cold Boot may be required and may be
more effective at clearing errors and restarting the application.