User manual

38
User Manual
Interface cards IF-XX
EN
Date: 04-09-2012
About the interface cards
6. CAN card IF-C1 / IF-C2
CAN Standard: V2.0 part A
Cable length: depending on the baud rate
The communication over the CAN bus is specifically desi-
gned to suit the needs of test applications and systems, like
for instance in the automotive industry. A subsequent imple-
mentation into existing systems and the modification of a
related software application is possible and unproblematic.
The networking of CAN devices provides the advantage of a
faster communication and a fail-safe bus topology. The driver
chip on the CAN card can support up to 110 device nodes
(the term „device node“ is used for CAN bus members).
The communication protocol can handle up to 30 units per
address segment (RID). Thus it is theoretically possible to
set up a bus system of up to 110 units, which will operate
with at least 4 address segments. The address segments
are relocatable, so that the one or multiple devices can be
implemented into an existing CAN bus without the need to
reconfigure the whole system.
6.1 Configuring the CAN card
The interface card is configured in the setup menu.
Since June, 2011 there is a new CAN ID system that will is
going to replace the old ID system. This is just done with a
software update of the device, the hardware is not effected.
You can recognize which of the CAN ID systems currently is
implemented in the device by the available setup menu items.
By selecting the card with
Slot: IF-C1 +
you enter the configuration menu for that particular card.
Each card has to be configured individually. You can now
setup some parameters.
Figure shows IF-C1 settings of the „old“ CAN-ID system,
see below
Setting the baud rate
All common baud rates between 10kBd and 1MBd are
supported. Only with PSI 9000 models, for each baud rate
setting the so-called „Sample point“ can be chosen, which
is used to optimise the data transmission for various cable
lengths and qualities. It adjusts the point of time when a
transmitted bit is sampled.
 baudrate Default: 100 kBd
sample point: 75% (only available with series PSI 9000)
= { 10 kBd { 60, 65, 70, 75, 80, 85}%,
20 kBd { 60, 65, 70, 75, 80, 85} %,
50 kBd { 60, 65, 70, 75, 80, 85} %,
100 kBd { 60, 65, 70, 75, 80, 85} %,
125 kBd { 58, 68, 70, 75, 81, 87} %,
250 kBd { 58, 68, 70, 75, 81, 87} %,
500 kBd { 58, 66, 75, 83} %,
1 MBd { 58, 66, 75, 83} % }
Bus termination
The CAN bus requires a termination resistor of 120 Ohms
on both ends of the line. If a unit is located at the end of the
chain/line and it is not connected to a next unit, it has to be
terminated. The parameter „bus terminate“ is used to easily
set the termination without any circumstancial hardware
termination by jumpers.
 bus terminate Default: NO
=YES The bus is terminated with a 120Ω resistor.
=NO No termination is done.
Gateway function (only PSI9000)
 CAN Default: Client
=Client The device is monitored and controlled by an
external unit, like a PC or a SPS
=Gateway The interface card additionally serves as a
gateway between the CAN and RS232/USB
cards
The RS232 or USB card inside the device which is assi-
gned as the gateway (here: PSI 9000) allows the user to
control and monitor all further units, which are linked to that
particular device by CAN. All that is needed is a device with
an extra IF-R1 or IF-U1 interface card to set up a CAN bus
system. Both cards, RS232 and USB, can only utilise the
high performance of the CAN bus very poorly. In order to
use the CAN bus with full performance (high data rate) and
many devices, it is recommended to directly control the bus
with a CAN master hardware.