User Manual

PD-1160 V1.1 Hardware Manual (Rev. 1.02 / 2013-JUL-23) 12
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3.2.2.2 CAN
For remote control and communication with a host system the PD-1160 provides a CAN bus interface.
Please note that the CAN interface is not available in case USB is connected. For proper operation the
following items should be taken into account when setting up a CAN network:
1. BUS STRUCTURE:
The network topology should follow a bus structure as closely as possible. That is, the
connection between each node and the bus itself should be as short as possible. Basically, it
should be short compared to the length of the bus.
c:>
node
1
node
n
- 1
node
n
Host
Slave Slave Slave
CAN
termination
resistor
(120 Ohm)
termination
resistor
(120 Ohm)
}
keep distance as
short as possible
Figure 3.6 CAN bus structure
2. BUS TERMINATION:
Especially for longer busses and/or multiple nodes connected to the bus and/or high
communication speeds, the bus should be properly terminated at both ends. The PD-1160 does
offer on-board termination resistors which can be activated with the help of a jumper (see
chapter 7). The jumper has to be removed for units not connected to one end of the bus!
3. NUMBER OF NODES:
The bus transceiver used on the PD-1160 units (TJA1050T or similar) supports at least 110 nodes
under optimum conditions. Practically achievable number of nodes per CAN bus highly depends
on bus length (longer bus -> less nodes) and communication speed (higher speed -> less nodes).