Goodrive600 series high-performance multifunction VFD
Communication networking
-157-
master/slave mode and is generally used for periodic data exchange between VFD devices. PRNV PROFIBUS-DP
adapter modules support only the PROFIBUS-DP protocol.
The transmission media of a PROFIBUS field bus are twisted pairs (complying with the RS-485 standard), paired cables,
or optical cables. The baud rate ranges from 9.6kbit/s to 12Mbit/s. The maximum length of a fieldbus cable must be
within the range of 100 meters to 1200 meters, and the specific length depends on the selected transmission rate (see
the chapter of "Technical Data"). A maximum of 31 nodes can be connected to one PROFIBUS network segment when
no repeater is used. If repeaters are used, a maximum of 127 nodes (including the repeaters and master nodes) can be
connected.
In PROFIBUS communication, tokens are transmitted between master nodes or by master nodes to slave nodes.
Single-master or multi-master systems are supported. The node to respond to the command of a master is selected by
the master node, generally a programmable logic controller (PLC). For cyclic master/slave user data transmission and
non-cyclic master-master data transmission, a master can also transmit commands to multiple nodes in broadcast mode.
When the broadcast mode is adopted, the nodes do not need to transmit feedback signals to the master. On PROFIBUS
networks, nodes cannot communicate with each other.
The PROFIBUS protocol is described in details in the EN50170 standard. For details, refer to the EN50170 standard.
6.5.2 Communication packet structure
The PROFIBUS-DP communication data frame structure (PKW+PZD) is similar to the PROFINET communication data
frame structure. For details, see 6.6.2 Communication packet structure.
Parameter
identification
(PKW)
Process data
(PZD)
Free allocated
zone
PKW1
PKW2
PKW3
PKW4
CW
SW
PZD2
PZD3
PZD2
PZD3
PZD12
PZD12
Fixed
zone
6.5.3 Baud rate and communication distance
The max. cable length depends on the transmission rate. The following provides the relationship between transmission
rates and transmission distances.
Table 6-24 Relationship between transmission rates and transmission distances
Transmission rate (Kbps)
Type-A cable (m)
Type-B cable (m)
9.6
1200
1200
19.2
1200
1200
93.75
1200
1200
187.5
1000
600
500
400
200
1500
200
-----
12000
100
-----
Table 6-25 Transmission cable specifications
Transmission rate (Kbps)
Type-A cable (m)
Type-B cable (m)
Impedance (ohm)
135
–165
100
–130
Capacitance per unit length (pF/m)
< 30
< 60
Loop resistance (Ohm/km)
110
--------
Core diameter (mm)
0.64
> 0.53
Core section (mm
2
)
> 0.34
> 0.22