Siemens CP 342–5 Manual page 9

Extended Master Functions
The CP 342-5/342-5 FO supports the following:
S SYNC/FREEZE (acyclic)
S Shared input/output (acyclic)
S Activating/deactivating DP slaves
S Modifications during runtime
– own PROFIBUS address
– DP mode (no DP, DP master, DP slave active/passive)
S Hardware interrupts / diagnostic interrupts
Hardware and diagnostic interrupts do not need to be evaluated in the user
program. Hardware and diagnostic interrupts are acknowledged automatically
by the CP.
You can use single diagnostics to obtain interrupt information.
Reaction Times of a DP Master
To calculate the reaction times when operating the module as a DP master, the
runtime of the function blocks required for DP processing in the S7-300 CPU
(DP_SEND, DP_RECV) is the decisive factor.
Table 1-3
Components
Runtime on the CPU 314-1
(6ES7 314–1AE04–0AB0)
1)
At data lengths > 240 bytes: The data is transferred segmented. This then involves several block calls.
Note
The reaction times listed above are only intended as a guideline and only apply to
a single-master configuration when no other services (for example PG functions)
are processed on the CP.
Manual CP 342–5 / CP 342–5 FO
C79000–G8976–C146/01
Explanation / Values (Guidelines)
Per DP_SEND block call:
S
0,2 – 3,4 ms at 16 bytes
S
0,2 – 5,9 ms at 240 bytes
Per DP_RECV block call:
S
0,3 – 3,5 ms at 16 bytes
S
1)
0,3 – 6,9 ms at 240 bytes
1)
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