Siemens CPU417-4 H Produktinformation Seite 15

3. Programming
I/O Access Errors Within DP
If errors occur accessing existing modules without an obvious cause (error-free station), it
might be because the parameter assignment monitoring time has been set too short (see also
the information on the parameter assignment monitoring time in Section 2, Configuration).
I/O Access Using Word and Double Word Commands
If, in the case of I/O access via word and double-word commands, the first byte or the first one
to three bytes are present, but the rest of the addressed range is not, "0" is loaded in the accu-
mulator.
Example: The I/O is present In the S7-400H with the addresses 8 and 9; the addresses 10
and 11 are not used. The access LED 8 results in the value "0000
cumulator.
Fewer Start Events for OBs 73 and 87
The operating system no longer triggers the events W#16#38DA and W#16#39DA (previously
start events for OB87) and W#16#72E0 and W#16#73E0 (previously start events for OB73).
OB73 therefore no longer has a function.
Disabling the Priority Classes By Means of SFC 39 and Entries in the Diagno-
stics Buffer
If you disable the priority classes by means of SFC 39 in the modes B#16#80, B#16#81 or
B#16#82, or the priority classes OB 70, OB 71, OB 72, as well as disabling OB 80, OB 81,
OB 82, OB 83, OB 86 and OB 87, then the causal event will still be entered into the diagnostics
buffer (the entry in the diagnostics buffer is suppressed for all other priority classes which are
disabled).
4. Modifications to the System During Operation
Performing an Operating System Update
In contrast to the information in Section 10.8 of the S7-400H Programmable Controller; Fault-
Tolerant Systems manual, an operating system update during operation to firmware version
V2.1.0 is not possible.
Adding and Removing Interface Modules
In contrast to the information in Section 10.1 of the S7-400H Programmable Controller; Fault-
Tolerant Systemsmanual, it is permissible to add and remove the interface modules IM460
and IM461 and the external DP master interface module CP443-5 Extended as well as all the
relevant connecting cables. Only remove and insert these hardware components in a deener-
gized state.
Below you will find a detail description of how to proceed. The references below are all to the
S7-400H Programmable Controller; Fault-Tolerant Systems manual.
A5E00073168-02
CPU 417-4H
" being loaded into the ac-
H
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