Parker Hannifin S.p.A S.B.C. Division SLVDN User’s Manual
Page 129 of 181
[BK+LUN] = the LUN field (first 3 bits) indicates the number of bytes of the data transmitted
(a parameter or a PLC instruction); the values can range from 1 to 4. This value does not
include eventual 0 characters ($00) which are inserted after the values that coincide with the
character of transmission start ($7E). The length of each parameter is two bytes.
The BK field is represented by the 5 most significant bits and represents the 5 most
significant bits of the parameter address.
[PAR] = write/read address of the parameter or PLC instruction.
The parameter address is the number of the parameter * 2 with 13 bit field: PAR represents
the least significant eight bits of the address, the 5 most significant bits must be written in the
BK field. The table used by electronic cam starts at the address 4096. The PLC instructions
have the address from 0 up to 255.
[D0]... [Dn] = data transmitted.
[CHK] = 256 module sum of all the fields excluding the [STX] (checksum).
Message types
[CMD1] = is the response message of the converter to a data request. The response message
has the following format:
[STX] [001+ADDR] [BK+LUN] [PAR] [D0]... [Dn] [CHK]
or it can be the confirmation message to a data write or data modify. In this case, the format is
the following:
[STX] [001+ADDR]
where ADDR always identifies which converter is answering.
[CMD2] = is the read message of an instruction in the PLC area. The message has the
following format:
[STX] [010+ADDR] [BK+LUN] [PAR] [CHK]
[CMD3] = is the write message to an instruction in the PLC area. The message has the
following format:
[STX] [011+ADDR] [BK+LUN] [PAR] [D0]... [Dn] [CHK]
[CMD4] = is the read message of a parameter. The message has the following format:
[STX] [100+ADDR] [BK+LUN] [PAR] [CHK]
[CMD5] = is the write message of a parameter. The message has the following format:
[STX] [101+ADDR] [BK+LUN] [PAR] [D0]... [Dn] [CHK]
CMD
bit 7 bit 6 bit 5 type of message
1 0 0 1 converter response
2 0 1 0 reading a pico-PLC instruction
3 0 1 1 writing a pico-PLC instruction
4 1 0 0 reading a parameter
5 1 0 1 writing a parameter
6 1 1 0 bit modification
7 1 1 1 writing a parameter to all the slaves
To Next Page
Loading...
