Baldor MintDrive, Installation Manual

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107
B.1 Outline
This section provides an introduction to the CAN (Controller Area Network) peripherals and how these
are configured to operate with the MintDrive.
B.1.1 MintDrive capabilities
The MintDrive can communicate with I/O expansion modules or other Mint v4 controllers via CAN,
and is compatible with DS-301, version 4 ( Application Layer and Communication Profile ) and
mandatory sections of DS-401, version 2 ( Device Profile for Generic I/O modules ). Some parts of
DS-403, version 1 ( Device Profile for Human Machine Interfaces ) are also supported. When connecting
third party devices please contact Baldor if you are unsure about compatibility.
CAN offers serial communications over a two wire twisted pair cable up to a maximum of 1640ft (500m)
in length, and offers very high communication reliability in an industrial environment; the probability of
an undetected error is 4.7x10
-11
. The default transmission rate is 125Kbaud although higher rates up to
1000Kbaud can be selected.
CAN is optimized for the transmission of small data packets and therefore offers fast update of I/O
devices (peripheral devices) connected to the bus. Several CAN peripheral devices may be attached to
the same controller via the CAN link using the CAL protocol. Up to 63 mixed type CAN peripherals may
be connected to the MintDrive CAN network, with the limitation that only 4 enabled keypads are allowed
at one time.
On the MintDrive, connection to the CAN networks are made using a 9-pin male D-type connector for
CAN bus channel 1 (CANopen) and a shielded RJ45 type connector for CAN bus channel 2 (Baldor
CAN). Both CAN channels are isolated. When MintDrive is at the end of a CAN network, the terminator
for that channel must be activated. The terminators are activated by setting the DIP switch on the front
panel to ON. Each CAN channel has its own DIP switch and terminator.
A very low error rate over CAN can only be achieved with a suitable wiring scheme, so the following
points should be observed:
H
CAN must be connected via twisted pair cabling to reduce RF emissions and provide immunity to
conducted interference. The connection arrangement is normally a simple multi-point drop. The
CAN cables should have a characteristic impedance of 120 Ω and a delay of 5ns/m. Other
characteristics depend upon the length of the cabling:
Cable length Maximum bit rate Resistance Conductor area
0ft ~ 131ft (0m ~ 40m) 1000Kbaud <70m Ω /m 0.25-0.34mm
2
131ft ~ 984ft (40m ~ 300m) 500Kbaud <60m Ω /m 0.34-0.60mm
2
984ft ~ 1968ft (300m ~ 600m) 100Kbaud <40m Ω /m 0.50-0.60mm
2
1968ft ~ 3280ft (600m ~ 1000m) 50Kbaud <26m Ω /m 0.75-0.80mm
2
B
CAN
B