Parker SPD 16, User Manual

Page: 92 / 110

Parker Hannifin S.p.A. Divisione.S.B.C. manuale d’uso SPD
91
14.2 Description of the fields in communication
mode
Write or parameter request message from the master to the
data write or request
Data length
7 bytes
Field Name
Cmd & Len Data Address Data
Contents
5 bit command and 3 bit
length
16 bit data address 32 bit data
Identifier
ID2 ID1 ID0 - - - - - ID10 ID9 ID8 ID7 ID6 ID5 ID4 ID3
A2 A1 A0 X X X X X 0 0 0 0 1 0 0 A3
A0:A3 SPD slave address (Pr27+1), valid values 1..15.
Cmd & Len Sub-field Value Meaning
Cmd [0..4] 0 Read request
1 Write
2 SET bit Pr = Pr .OR. Data
3 RESET bit Pr = Pr .AND.
(.NOT.Data)
4 TOGGLE bit Pr = Pr .XOR. Data
5 – 31 Not used
Len [5..7] 0- 4 Number of significant bytes in the data field
Data Address
This is the address of the parameter interested in the operation (parameter number * 2).
The PLC instructions have the address from 8192 up to 8447.
The electronic cam table have the address from 4096 to 4610.
Data
If the parameter is written, it contains the value of the parameter.
If one or more bits are modified, it contains the mask of the bits to be modified.
If the parameter is to be read, the field has no meaning.
If plc programme is written, it contains the instruction code (see the section
Serial interface
).