EM-RES-03 3110/07
5.10.2 Communication via field bus connection (SDO1)
If an frequency inverter has been defined as the system bus master and equipped with
a field bus interface, access to the parameterization of all the subscribers in existence
on the system bus is possible by means of this field bus interface via the first SDO
channel (SDO1). An extension has been created in the protocol frame of the field
buses for this purpose.
Attention: The prerequisite for this mechanism is that the identifier setting for the
first SDO channel (SDO1) corresponds to the Predefined Connection Set.
The parameter addressed must also be existent in the system bus mas-
ter.
5.10.2.1 Profibus-DP
If an object with communication channel (PKW) is used in Profibus-DP, access to all
the other subscribers on the system bus can be done via it. The structure of the com-
munication channel permits an additional addressing of a system bus subscriber. This
is done by the use of an unused byte in the communication channel.
Communication channel PKW
0 1 2 3 4 5 6 7
PKE Index - Data
AK/SPM Parameter
number
Data set Node-ID
system bus
Byte 3 is used to transmit the node ID of the required subscriber on the system bus. If
byte 3 = 0, the master inverter of the system bus is addressed. The display is binary
(0...63).
5.10.2.2 RS232/RS485 with VECTRON bus protocol
In the VECTRON bus protocol, there is a byte in the telegram header that is always
transmitted with 0 as a standard feature.
ENQUIRY
0 1 2 3 4 5 6
Address 0 p n n n ENQ
Node-ID
system bus
Data set Parameter number
SELECT
0 1 2 3 4
Address STX 0 p n n n ...
Node-ID
System bus
Data set Parameter number
Byte 1 in the enquiry and byte 2 in the select telegram are not defined and are used to
transmit the node ID of the required subscriber on the system bus. If this byte = 0,
the master inverter of the system bus is addressed. The display is ASCII corresponding
to the conventions for the display of the address in the VECTRON bus protocol.
Note: If there is an NAK fault message, the error is to be read out from the
system bus master with node ID = 0 via parameter 11.