Siemens SIMATIC CP 340, Руководство пользователя

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Communication using function blocks
6.8 Technical data of the function blocks
PtP coupling and configuration of CP 340
Manual, 04/2011, A5E00369892-03
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6.8 Technical data of the function blocks
Introduction
Listed below is the technical specifications relating to memory requirements, runtimes,
minimum number of CPU cycles, and system functions used.
Memory requirements
The table below lists the memory requirements of the CP 340 function blocks/functions.
Table 6- 8 Memory requirements of the function blocks/functions (in bytes)
Block Name Version Load memory Work memory Local data
FB 2 P_RCV 2.0 2264 1888 40
FB 3 P_SEND 2.0 1942 1590 40
FB 4 P_PRINT 2.0 2094 1726 44
FB 12 P_RESET 1.0 1454 1170 30
FC 5 V24_STAT 2.0 182 108 2
FC 6 V24_SET 2.0 150 84 2
Minimum number of CPU cycles
The table below describes the minimum number of CPU cycles (FB/FC calls) required to
process a "minimum job" (14 bytes SEND, 13 bytes RECEIVE for the quantity of user data
transported per program cycle). This only applies in centralized operation.
Table 6- 9 Minimum number of CPU cycles
Number of CPU cycles for processing ...
Termination without
error
Termination with error RESET/RESTART
RECEIVE ≥3 ≥ 3 ≥ 4
SEND ≥ 3 ≥ 3 ≥ 4
PRINT ≥ 3 ≥ 3 ≥ 4
V24_STAT 1 - -
V24_SET 2 >> 2 -
Before the CP 340 can process an activated job after the CPU has changed from STOP to
RUN mode, the CP-CPU startup mechanism of the P_SEND or P_PRINT function block
must have been completed. Any requests initiated in the meantime do not get lost. They are
transmitted once the start-up coordination with the CP 340 is finished.
Before the CP 340 can receive a frame in the user program after a change in the CPU mode
from STOP to RUN, the CP-CPU startup mechanism "RCV" must be completed.