User manual

Copyright IXXAT Automation GmbH
CAN-CR2xx - Manual, V2.0
Configuration
13
3.3 Configuration of the lock time
With DIP switch S302 the lock time of the CAN-Repeater is defined. This time is
used to avoid bit errors created by the device itself in a result of the signal propa-
gation delay. Such an error could be a short dominant level inside of a recessive
bit, which could cause bit errors at other CAN nodes (depending on the sampling
point).
The setting of the lock time has to be done according to the baudrate and the
capacitive load of the network.
S302-1 S302-2 S302-3 S302-4 Lock time in ns
(tolerance ±10%)
OFF OFF OFF OFF 100
Default OFF OFF OFF ON 300
OFF OFF ON OFF 500
OFF OFF ON ON 800
OFF ON OFF OFF 1000
OFF ON OFF ON 1300
OFF ON ON OFF 1500
OFF ON ON ON 1800
ON OFF OFF OFF 2000
ON OFF OFF ON 2300
ON OFF ON OFF 2500
ON OFF ON ON 2800
ON ON OFF OFF 3000
ON ON OFF ON 3300
ON ON ON OFF 3500
ON ON ON ON 3800
Table 3-3 Configuration of the lock time
For reference values the following settings can be taken:
- for networks with less than 32 nodes the minimum lock time should
be about 300 ns
- for networks between 32 and 64 nodes a minimum lock time of 500 ns
should be used
- for networks with more the 64 nodes a minimum lock time of 1 µs should be
used, but with this setting the maximum baudrate is limited to 500 kBd.