ProSoft Technology MVI56-AFC - Manual (Page 132)

Events MVI56-AFC ♦ ControlLogix Platform
User Manual Liquid and Gas Flow Computer
Page 132 of 316 ProSoft Technology, Inc.
February 25, 2011
9.5.6 Modbus Transaction Sequencing and Constraints
This section describes the details of the Modbus transactions that manage a log-
download session, including full specifications of transaction contents and the
conditions under which they are permitted. Also considered is smooth recovery
from failed transactions, as might happen over an intermittently failing
communication link; the general principle is that an otherwise valid transaction
may be repeated as many times as is necessary to ensure success.