NORDAC FLEX (SK 200E ... SK 235E) – Users Manual for Frequency Inverters
262
BU 0200 en-US-4920
Physical structure
Standard
CAN
Physical design
2x2, twisted pair, shielded, stranded wires, wire cross-
section ≥0.25
mm² (AWG23),
surge impedance approx. 120
Ω
Bus length
max. 20 m total network
max. 20 m between 2 subscribers
Structure
preferably linear
Spur cables
possible, (max. 6 m)
Termination resistors
120
Ω
, 250 mW at both ends of a system bus
(with VFD or SK xU4-… via DIP switches)
Baud rate
250 kBaud - pre-set
The CAN_H and CAN_L signals must be connected using a
twisted pair of wires. The GND potentials are connected using
the second pair of wires.
Addressing
If several variable frequency drives are connected to a system bus, these devices must be assigned
with unique addresses. This happens preferably through the DIP switch S1 on the device (please see
chapter 4.3.2.2 "DIP switches (S1)").
For field bus modules, no assignment of addresses is necessary. The module identifies all the variable
frequency drives automatically. Access to the individual inverters takes place via the field bus master
(PLC) Details of how this is carried out are explained in the relevant bus instructions or data sheets
for the individual modules.
I/O extensions must be assigned to the relevant variable frequency drive. This is carried out by means
of a DIP switch on the I/O module. A special case for the I/O extensions is the "Broadcast" mode. In
this mode, the data from the I/O extension (analogue values, inputs etc.) are sent to all inverters
simultaneously. Via the parameterization in each individual variable frequency drive, a decision is
made as to which of the received values are to be used. More information about the settings can be
found in the
Information
Addressing
Care must be taken that each address is only assigned once. In a CAN-based network double assignment of
addresses may lead to misinterpretation of the data and therefore undefined activities in the system.
Integration of devices from other manufacturers
In principle, the integration of other devices into this bus system is possible. These must support the
CANopen protocol and a 250 kBaud baud rate. The address range (Node ID) 1 to 4 is reserved for
additional CANopen masters. All other participants must be assigned addresses between 50 and 79.
