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5-22 Input / Output
MN1943
5.7 CAN interface
The CAN bus is a serial based network originally developed for automotive applications, but now
used for a wide range of industrial applications. It offers low-cost serial communications with very
high reliability in an industrial environment; the probability of an undetected error is 4.7x10
-11
.
It is optimized for the transmission of small data packets and therefore offers fast update of I/O
devices (peripheral devices) connected to the bus.
The CAN protocol only defines the physical attributes of the network, i.e. the electrical,
mechanical, functional and procedural parameters of the physical connection between devices.
The higher level network functionality on MotiFlex
e
100 is defined by the CANopen protocol, one
of the most used standards for machine control.
5.7.1 CAN connector
Location
CAN (top panel)
Mating connector: 9-pin female D-type
Pin Name
Description
1 -
(NC)
2 CAN-
CAN channel negative
3 CAN GND Ground/earth reference for CAN signals
4 -
(NC)
5 Shield
Shield connection
6 CAN GND Ground/earth reference for CAN signals
7 CAN+
CAN channel positive
8 -
(NC)
9 CAN V+
CAN power V+ (12-24 VDC)
5.7.2 CAN wiring
A very low error bit rate over CAN can only be achieved with a suitable wiring scheme, so the
following points should be observed:
H
The two-wire data bus line may be routed parallel, twisted and/or shielded, depending on
EMC requirements. Baldor recommend a twisted pair cable with the shield/screen
connected to the connector backshell, in order to reduce RF emissions and provide immunity
to conducted interference.
H
The bus must be terminated at both ends only (not at intermediate points) with resistors of a
nominal value of 120
Ω
. This is to reduce reflections of the electrical signals on the bus,
which helps a node to interpret the bus voltage levels correctly. If the MotiFlex
e
100 is at the
end of the network then ensure that a 120
Ω
resistor is fitted (normally inside the D-type
connector).
H
All cables and connectors should have a nominal impedance of 120
Ω
. Cables should have
a length related resistance of 70 m
Ω
/m and a nominal line delay of 5 ns/m.
1
5
6
9
Summary of Contents for MotiFlex e100
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Page 60: ...www baldormotion com 3 44 Basic Installation MN1943 ...
Page 102: ...www baldormotion com 5 28 Input Output MN1943 ...
Page 136: ...www baldormotion com 7 8 Troubleshooting MN1943 ...
Page 172: ...www baldormotion com 8 36 Specifications MN1943 ...
Page 188: ...www baldormotion com B 6 Control System MN1943 ...
Page 204: ...www baldormotion com C 16 Mint Keyword Summary MN1943 ...
Page 216: ...Index MN1943 ...
Page 218: ...www baldormotion com Comments MN1943 Thank you for taking the time to help us ...
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