Rockwell Automation T8xxx Application Note Trusted Intelligent Online Updates - Manual (Page 24)

Trusted TM
AN-T80009 Trusted
TM
Intelligent Online Updates
Issue 4 Nov 08 AN-T80009 24
1.13.18. Communications Blackout
During an update, the communications module Modbus task stops and restarts briefly (less than 1
second). This may be sensed by remote devices (e.g. OPC server, Modbus Masters) as a break in
communications and may cause alarms or failover actions as set up in the remote device.
With OPC server build 109 and earlier and communications interface (8151B) firmware 121, the OPC
server will not understand the ‘Slave Device Busy’ message sent by the 8151B and will take several
minutes to resynchronise. See TN20065. Upgrade the OPC server to the latest build.
1.13.19. Compilation for Intel
If the compiler options are set for Intel (for the NT Target/Target Simulator) as well as Motorola (for the
real system), then confusing contradictory messages may occur, implying first that an intelligent update
will be used, and then that an intelligent update is not possible. This is because the Intelligent Update
Manager is keeping track of the last downloaded snapshot for both versions, and the application has
moved on significantly since the last download to the Target Simulator. Before compiling for an online
update to a live system, first deselect the ‘TIC Code for Intel’ option in the Compiler Options. The
Intelligent Update Manager will then only compare against the Motorola code. The compilation will also
run more quickly.
1.13.20. Constant variables not updating when set to 0 initially
If an integer or real variable of type ‘Constant’ is created with an initial value of zero (‘0’), and the value
is changed on line, the offline dictionary will not be updated with the new value despite the message
given on changing the value. Therefore if a ‘Constant’ variable with an original initial value of zero is
changed online, the offline dictionary must also be manually changed.
1.13.21. Power Flow Debugging option change causes update problems on
untouched programs
This applies to Toolset versions before 3.51 build 111 (release 3.5.1), which fixes the problem. The
problem has been observed using Toolset version 3.46 build 9 and was fixed online by upgrading the
Toolset as described in section 1.13.1.
If an application is downloaded using one PC, and then the application is worked on using another PC,
then the intelligent online update (IOU) manager may report that unchanged programs include
deleted/new function blocks.
The cause is the option for ‘Enable Power Flow Debugging’. If the application was previously compiled
with the option on, and the application is then moved to a PC where the power flow debugging is turned
off, then some or all programs will lose all their internal power flow debugging variables and the IOU
will be unable to match the old and new function blocks that had inputs from these power flow
debugging variables.
The IOU manager uses the intermediate ‘Preprocessor output’ to make its decision on function block
matching. This code may be viewed after verifying a program. Instead of clicking ‘Exit’, on the final
dialog, click Continue. Select menu option Edit | Preprocessor Output.
Function block diagram programs are translated into an internal Structured Text equivalent as shown
in the example shown on the next page.