PROTOCOL COMMUNICATION
PT10789220
pag. 5/22
5. Telegram Control
The basic operations that must be performed in order to get data from NEMO 96HD are described in the following part of
the document.
Note
1. In the following of the document when referring to a bit, the notation "B.b" will be used where 'B' means BYTE and 'b'
means bit. So, for example, 3.4 means bit 4 of BYTE 3.
2. There is a variable, named "block number" which is initialized to 1 at the beginning.
The simplified sequence for retrieving data from NEMO is :
1. PLC sets bit 2.0 ( = 1 ).
The next telegram sends the information to NEMO 96HD
=>
the internal retrieving process starts
2. If the internal sequence has started (bit 3.4), PLC resets bit 2.0 and waits for the completion of the internal operation
(bit 3.4 or bit 3.5)
3. The first telegram from NEMO that contains the end condition also contains the first data packet.
4. By other 6 telegrams the PLC requires the other 6 data packet from NEMO 96HD and then the whole process may
restart again.
Note : in multi-byte data, the adjustment of the BYTEs is as following :
MSB MB2 MB1 LSB
E.g.
Decimal 123456 = 01e240
MSB MB2 MB1 LSB
00 01 e2 40
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