VIPA CPU 21 Series, Руководство пользователя

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Manual VIPA CPU 21x Chapter 10 Deployment CPU 21xSER-2
HB103E - Rev. 05/45 10-9
Initialize interfaces
The initialization of the interfaces happens in OB 100 and should be
executed with the following approach:
•
Call SYNCHRON with SFC 235 and enter the wanted block size (page
frame basic address=0, block size, PAFE)
•
Parameterize the interfaces via SEND (SFC 230) with order no. 201 and
parameter DB
•
To take over the parameters, call RESET (SFC 234) with order no. 0
The SYNCHRON block initializes the synchronization between CPU and
CP during the boot process and for this it has to be called in the start-up
OB 100. Simultaneously the transition area of the interface is deleted and
predefined and the CP and the CPU agree about the block size.
Number of the logical interface (page frame address) to which the
according order refers to. SSNR must be 0!
To avoid long cycle run-times it is convenient to split large data amounts
into smaller blocks for transmitting them between CP and CPU. You
declare the size of this blocks by means of „block size“.
A large block size = high data throughput, but also longer run-times and
therefore a high cycle time strain.
A small block size = smaller data throughput, but also shorter run-times of
the blocks.
Following block sizes are available:
Value Block size Value Block size
0 Default (64Byte) 4 128Byte
1 16Byte 5 256Byte
2 32Byte 6 512Byte
3 64Byte 255 512Byte
Parameter type : Integer
Valid range : 0 ... 255
CALL SFC 235
SSNR:=0
BLGR:=6
PAFE:=MB199
Overview
SFC 235
SYNCHRON
Parameter
SSNR
Block size
Example