IMC CANSAS - CAN-Bus-Wiring; Connecting the Terminators

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imc CANSAS Users Manual - Doc. Version 1.9 - 05.12.2014© 2014 imc Meßsysteme GmbH
2.6.3 CAN-Bus-wiring
Connecting imc CANSAS without a tee-junction is recommended
In this case the module has 2 sockets; an input and an output as per CiA :
One 9-pin, male DSUB socket and one 9-pin, female DSUB socket or two 10-pin LEMO.1B.310 sockets
at SL modules.
This is the preferable alternative for connecting, and this is the only alternative imc CANSAS is
designed for. In this case it doesn't matter whether other sensors are connected with the CAN-Bus
with or without tee-junctions. The illustration shows an example of several imc CANSAS-modules and
an imc device all connected via CAN-Bus.
CANSAS connected without tee-junction
Connecting imc CANSAS with a tee-junction is Not recommended
If a module has only one terminal socket, then this one socket is 9-pin female. In this case, an external
tee-junction must be used.
Note that with a CAN-Bus data transfer rate of 1Mbit/s, the tee-junction stub line may only be max.
30cm long. Therefore, if an external tee-junction is connected, plug the junction directly into the
module socket.
2.6.4 Connecting the terminators
The terminators' resistance is 124W as per CiA .
Connect terminators between Pins 2 and 7, if applicable.
Terminators are connected at both ends of the bus. There is no other place in the line where they may be
connected. The bus must end at terminators.
Safety note!
In general, it is OK to pull the CAN-plug during operation. When it is re-plugged afterwards, reset of
the imc CANSAS-module's CAN-controllers will automatically be carried out, and then it will resume
working with the CAN-Bus. However, the device is not designed to allow operation under these
circumstances; it normally functions acceptably, but this cannot be guaranteed. For example, re-
connecting can lead to an electrostatic discharge where voltages higher than permitted can develop
and cause fatal damage to the circuitry. A person can receive a charge of 1000 V from an electric
discharge; much higher than specified in ISO 11898. To ensure proper functioning, it is best to
switch imc CANSAS off and then on again.