4 Commissioning
4.12 Acyclic data
88
DX-NET-PROFINET2-2
01/22 MN040062EN
www.eaton.com
Write request - write job
Only individual parameter writing is supported (i.e., array and multiple para-
meter writing is not supported). The maximum telegram length of the para-
meter request is set at 16 bytes. The maximum length of a writable parame-
ter is one double word. Various objects can be transmitted in the parameter
channel – these objects are identified by what is referred to as a PNU (para-
meter number) and a subindex. The write request includes a declaration that
specifies that the job is a write job.
Table 47:
Write request
In this case, the number of bytes is variable (13, 14, or 16) and will depend on
the selected format
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. They are then mirrored by variable
frequency drive/variable speed starter.
01
hex
- FF
hex
(i.e. 1
dec
- 255
dec
)
1
Request ID
Request ID
Specifies the type of request.
02
hex
: Write job
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.
10h
ex
(16
dec
): Value
5
No. of Elements
Number of elements
Number of vector elements or length of the string being accessed
PNU 0 to PNU 999: 00
hex
(only for subindex 0)
PNU 0 to PNU 999: 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
)
10
Format
Format
01
hex
- 7C
hex
(i.e. 01
dec
- 124
dec
): Data types
11
No. of Values
Number of values
Number of values being accessed.
01
hex
12 - (15)
Value
Value
The value of the parameter being accessed
The length depends on the format and can be a maximum of 4 bytes.
00000000
hex
- FFFFFFFF
hex
(i.e. 0
dec
- 4294967295
dec
)
