Eaton DS7 - Page 203

8 SmartWire-DT
8.9 Programming
DS7 Soft starter 09/16 MN03901001Z-EN www.eaton.com 199
8.9.6.3 SmartWire-DT write request – Read job
Only individual parameter reading is supported (i.e., array and multiple
parameter reading is not supported). The parameter request’s frame length
is set at 10 bytes.
Various objects can be transmitted in the parameter channel – these objects
are identified by what is referred to as a PNU (parameter number) and a
subindex. The write request includes a declaration that specifies that the job
is a read job.
Byte Designation Description
0 Request Reference Request identification:
Unique identification for a request/response pair for the master.
The master can increment the identification number for each new
request in the application.
It will be echoed by the DS7-SWD soft starter after this.
01
hex
- FF
hex
(i.e. 1
dec
- 255
dec
)
1 Request ID Request ID:
The type of request is specified here.
01
hex
: Read request
2 DO-ID Drive-Object-ID:
00
hex
3 No. of Paramters Number of parameters:
Only individual parameter processing is supported.
01
hex
4 Attribute Attribute:
Defines which object type should be accessed.
10
hex
(16
dec
): Value
5 No. of Elements Number of elements:
Address of the parameter that should be accessed
PNU 0 - PNU 999: 00
hex
(for subindex 0 only)
PNU 0 - PNU 999 (without 202): 01
hex
6, 7 Parameter number Parameter number (PNU):
Address of the parameter that should be accessed
0000
hex
- FFFF
hex
(i. e. 0
dec
- 65535
dec
)
8, 9 Subindex Subindex:
Address of the parameter’s first field element or start of the text
0000
hex
- FFFF
hex
(i. e. 0
dec
- 65535
dec
)
￫
In this case, the number of bytes is always 10.