VIPA CP 240 RS232, Manual

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Chapter 5 CP 240 - EnOcean Manual VIPA System 200V
5-8 HB97E - CP - Rev. 11/30
For the deployment of the CP 240 together with a System 200V CPU VIPA
offers handling blocks that enable a comfortable software handshake.
For the deployment of the CP 240 without handling blocks, the following
text shows the functionality for transmitting and receiving data with an
example.
An EnOcean telegram contains 11Byte user data. At the transmission the
CPU writes for every telegram 11Byte user data into the Bytes 4 to 14 and
into Byte 2/3 the length of the telegram (i.e. "11"). The CP 240 receives the
data via the back plane bus. To acknowledge the telegram, the CP 240
writes the value "11" (length of the telegram) back to the CPU into Byte
2/3.
At reception of this "11" in Byte 2/3 the CPU sends back a "0" at Byte 2/3.
Thereupon the user data in the CP 240 are supplemented to 14Byte with 2
sync bytes at the beginning and the Checksum at the end and stored in the
send buffer. After this, the CP responds with a "0" at Byte 2/3. After the
CPU received this "0", it may send a new telegram to the CP 240.
The telegrams stored in the send buffer are immediately transmitted via
EnOcean.
Every EnOcean telegram has a size of 14Byte. When the CP 240 receives
a telegram this is stored in the receive buffer. For every telegram the
11Byte of user data are handled over to the CPU via the back plane bus
into Byte 4 to 14 and the length (i.e. "11") into Byte 0/1. The first two sync
bytes and the Checksum are deleted.
The CPU stores the user data and responds with the value "11" at
Byte 0/1. The CP acknowledges this with a "0" at Byte 0/1 and thus
announces that the transfer has been completed. As soon as new data
may be transferred the CPU answers with "0".
With the reception of "0" the CP 240 may send a new telegram to the CPU.
Software
handshake
Example
transmitting data
w/o handling blocks
Example receiving
data without
handling blocks