MN1941WEN Input / Output 4-29
All cables and connectors should have a nominal impedance of 120 Ω. Cables should
have a length related resistance of 70 mΩ/m and a nominal line delay of 5 ns/m.
The maximum bus length depends on the bit-timing
configuration (baud rate). The table opposite shows
the approximate maximum bus length (worst-case),
assuming 5 ns/m propagation delay and a total
effective device internal in-out delay of 210 ns at
1 Mbit/s, 300 ns at 500 - 250 Kbit/s, 450 ns at
125 Kbit/s and 1.5 ms at 50 - 10 Kbit/s.
(1)
For bus lengths greater than about 1000 m,
bridge or repeater devices may be needed.
The compromise between bus length and CAN baud
rate must be determined for each application. The
CAN baud rate can be set using the BUSBAUD
keyword. It is essential that all nodes on the network are configured to run at the same
baud rate.
The wiring topology of a CAN network should be as close as possible to a single line/bus
structure. However, stub lines are allowed provided they are kept to a minimum (<0.3 m
at 1 Mbit/s).
The 0 V connection of all of the nodes on the network must be tied together through the
CAN cabling. This ensures that the CAN signal levels transmitted by NextMove e100 or
CAN peripheral devices are within the common mode range of the receiver circuitry of
other nodes on the network.
4.7.2.1 Opto-isolation
On the NextMove e100, the CAN channel is opto-isolated. A voltage in the range 12-24 V
must be applied between pin 9 (+24 V) and pin 3 or 6 (0 V) of the CAN connector. From this
supply, an internal voltage regulator provides the 5 V at 100 mA required for the isolated
CAN circuit. A connector such as the Phoenix Contact SUBCON-PLUS F3 (Phoenix part
2761871) provides a 9-pin D-type female connector with easily accessible terminal block
connections. CAN cables supplied by ABB are ‘category 5’ and have a maximum current
rating of 1 A, so the maximum number of NextMove e100 units that may be used on one
network is limited to ten.
4.7.3 CANopen
ABB has implemented a CANopen protocol in Mint (based on the ‘Communication Profile’
CiA DS-301) which supports both direct access to device parameters and time-critical
process data communication. The NextMove e100 complies with CANopen slave device
profile DS402, and can be a DS401 or DS403 master device. It is able to support and
communicate with a variety of devices including:
Any third party digital and analog I/O device that is compliant with the ‘Device Profile for
Generic I/O Modules’ (CiA DS-401).
Baldor HMI (Human Machine Interface) operator panels, which are based on the ‘Device
Profile for Human Machine Interfaces’ (DS403).
Other ABB controllers with CANopen support for peer-to-peer access using extensions
to the CiA specifications (DS301 and DS302).
The functionality and characteristics of all ABB CANopen devices are defined in individual
standardized (ASCII format) Electronic Data Sheets (EDS) which can be found on the Mint
Motion Toolkit CD (OPT-SW-001), or downloaded from www.abbmotion.com.
CAN
Baud Rate
Maximum
Bus Length
1 Mbit/s
500 Kbit/s
250 Kbit/s
125 Kbit/s
100 Kbit/s
50 Kbit/s
20 Kbit/s
10 Kbit/s
25 m
100 m
250 m
500 m
600 m
1000 m
2500 m
(1)
5000 m
(1)