Siemens SIMATIC FM 452, Руководство пользователя

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Programming the FM 452
6-20
FM 452 Electronic Cam Controller
C79000-G7076-C452-04
6.9 Fast Access to Module Data
Application
In special applications or in an interrupt level, particularly fast access to return and
control signals is necessary. You can obtain this data directly via the input and
output areas of the module.
To coordinate startup following each module startup (for example after inserting the
module, CPU STOP
→
RUN), FC CAM_CTRL must be called continuously until
the end of the startup is indicated by RET_VAL = 0.
Note
If you access data on the FM 452 directly, you must only use the non-internal data
described here using the method described here. Otherwise, your user program
will encounter difficulties accessing the module.
Direct Access for Reading Return Signals
The byte addresses are specified relative to the output address of the module. The
names of the bits correspond to the names in the channel DB.
In STL, you access the data with the commands PIB (read 1 byte) and PID (read
4 bytes).
Address Bit Number
7 6 5 4 3 2 1 0
Byte 0 PARA intern
al internal DATA_ERR internal DIAG internal internal
Byte 1 0 0 0 CAM_ACT 0 0 0 0
Byte 2 internal
Byte 3 0 0 FVAL_DONE HYS GO_P GO_M MSR_DONE SYNC
Byte 4
Byte 5
ACT_POS
Byte 6
Byte 7
Byte 8
Byte 9
TRACK_OUT
Byte 10
Byte 11