VIPA CPU 21 Series, Руководство пользователя

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Manual VIPA CPU 21x Chapter 10 Deployment CPU 21xSER-2
HB103E - Rev. 05/45 10-15
If the CP is able to take over the data directly, the SEND block transfers
the requested data in one session. If the CP requests only the order
parameters or the amount of the depending data is too large, the CP only
gets the sending parameters res. the parameter with the first data block.
The according data res. the assigned serials blocks for this order are
requested from the CP by SEND_ALL to the CPU. For this it is necessary
that the block SEND_ALL is called minimum one time per cycle.
The RECEIVE block receives data from a CP.
Normally the RECEIVE block is called in the cyclic part of the user
application program.
For activating a RECEIVE block is only started, if:
•
the RECEIVE has received a VKE "1"
•
the CP released the order (Bit "Handshake convenient" = 1)
Via the RECEIVE_ALL block, the data received from the CP is transmitted
from the CP to the CPU by using the declared block size.
Location and size of the data area that is to transmit with RECEIVE_ALL,
must be declared before by calling RECEIVE.
In the indicator word that is assigned to the concerned order, the bit
"ENABLE/DISABLE" is set, "Data transition starts" and "Data transi-
tion/fetch running" is analyzed or altered. The receiving amount is shown in
the following word.
Note!
In the following cases, the RECEIVE_ALL command has to be called for
minimum one time per cycle of the block OB1:
•
if the CP should send data to the CPU independently
•
if a CP order is initialized via RECEIVE, but the CP still has to request
the background communication data of the CPU for this order.
•
if the amount of data, that should be transmitted to the CPU by this
RECEIVE, is higher than the declared block size.
SEND_ALL for
data transmission
SFC 231 - RECEIVE
Parameter
SFC 237 -
RECEIVE_ALL
Parameter