Profibus-Dp Networking; Service Access Point; Profibus -Dp Information Frame Data Structure - INVT Goodrive3000 Series Operation Manual

Goodrive3000 series medium voltage VFD

9.4 PROFIBUS-DP Networking

PROFIBUS-DP is a distributed I/O system, which enables master machine to use a large number of peripheral modules
and field devices. Data transmission shows cycle: master machine read input information from subsidiary machine then
give feedback signal. EC-TX103 communication card supports PROFIBUS-DP protocol.

9.4.1 Service access point

PROFIBUS-DP has access to PROFIBUS data link layer (Layer 2) services through service access point SAP. Every
independent SAP has clearly defined function. Please refer to relevant PROFIBUS user manual to know more about
service access point information. PROFIDRIVE - Variable speed drive adopts PROFIBUS model or EN50170 standards
(PROFIBUS protocol).

9.4.2 PROFIBUS -DP information frame data structure

PROFIBUS-DP bus mode allows rapid data exchange between master station and VFD. Adopting master-slave mode
dealing with VFD access, VFD is always subsidiary station, and each has definite address. PROFIBUS periodic
transmission messages use 16 words transmission, the structure shown in Figure 9-7.
Parameter identification (PKW) zone
Parameter identification (PKW): PKW zone describes treatment of parameter identification interface, PKW interface is a
mechanism which determine parameters transmission between two communication partners, such as reading and writing
parameter values.
In the process of periodic PROFIBUS-DP communication, PKW zone is composed of four words (16 bit), each word is
defined as follows:
Bit
The first word PKW1 (16
bit)
The second word PKW2
(16 bit)
The third word PKW3
(16 bit)
The fourth word PKW4
(16 bit)
Note: If the master node requests the value of a parameter, the values in PKW3 and PKW4 of the packet that the
master node transmits to the VFD are no longer valid.
Task request and response: When transmitting data to a slave node, the master node uses a request number, and the
slave node uses a response number to accept or reject the request. Table 9-3 lists the request/response function.
The definition of task identification flag PKW1 is as follows:
Parameter identification (PKW)
PKW1 PKW2 PKW3
Figure 9-7 PROFIBUS-DP packet structure
Parameter
identification (PKW)
PKW1 PKW2 PKW3
Request
Parameter
Parameter
No.
value error
Response address
No.l
Figure 9-8 Parameter identification zone
Bit
Bit 15–00
Bit 15–00
Bit 15–00 Parameter value (MSB) or return error code value
Bit 15–00
Process data (PZD)
Fixed
Free allocation zone
zone
CW PZD2 PZD3
PKW4
SW PZD2 PZD3
Process data
CW PZD2
PKW4
SW PZD2
Parameter
value
No.
Definition
Task or response identification marks
Basic parameter address
Parameter value (LSB)
-217-
PROFIBUS communication
... PZD12
PZD12
Range
0–7
0–247
0–65535
00