VIPA CP 240 RS232, Руководство пользователя

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Chapter 4 CP 240 - serial Manual VIPA System 200V
4-18 HB97E - CP - Rev. 11/30
For the deployment of the CP 240 together with a System 200V CPU VIPA
offers you a series of standard handler blocks that provide the software
handshake comfortable and easy.
At deployment of the CP 240 without handler blocks, the functionality is
elucidated with an example of data send and receive.
For example, a telegram with 30Byte length is to send. The CPU writes the
first 12Byte user data of the telegram into the Bytes 4 to 15. Byte 2/3
contain the telegram length, i.e. "30". The CP 240 receives the data via the
back plane bus and copies the 12Byte user data into the send buffer. For
the acknowledgement of the telegram the CP 240 writes the value "30"
back to Byte 2/3 (length of the telegram).
At reception of the "30", the CPU can send further 12Byte user data to Byte
4 to 15 and the rest length of the telegram ("18" Byte) to Byte 2/3 to the
CP 240. Again, this stores the user data in the send buffer and sends back
the length information ("18") in Byte 2/3 to the CPU.
The CPU receives the "18" and sends the remaining 6Byte user data in the
Bytes 4 to 9 and the according rest length ("6") in Byte 2/3 to the CP 240.
The user data is stored in the send buffer and the value "6" is send back to
the CPU via Byte 2/3.
The CPU receives the "6" and sends back a "0" via Byte 2/3. The CP 240
now initializes the sending of the telegram via the serial interface. After
data transfer is completed, the CP 240 sends back a "0" to the CPU via
Byte 2/3.
At reception of the "0", the CPU is able to send a new telegram to the
CP 240.
The interface of the CP 240 has e.g. received a telegram with a length of
18Byte via the serial interface. The CP 240 writes the 12Byte user data into
the Bytes 4 to 15 of the receive buffer and the telegram length (i.e. "18")
into Byte 0/1. The data is transferred to the CPU via the back plane bus.
The CPU stores the 12Byte user data and sends back the length value "18"
to the CP 240.
At reception of the "18", the CP 240 writes the remaining 6Byte user data
into the Bytes 4 to 9 of the receive buffer and the received length of user
data ("6") in Bytes 0/1. The user data are stored by the CPU and "6" in
Byte 0/1 is returned to the CP 240.
Having received the "6", the CP 240 returns the value "0" via Byte 0/1, i.e.
the telegram has been completed. The CPU acknowledges with another
"0" in Byte 0/1 to the CP 240.
Receiving "0" the CP 240 may send another telegram to the CPU.
Software
handshake
Example
SEND data
Example
RECEIVE data