blue PiraT2 / 5E / 5E
User Guide
Datum: 21.09.2016
Seite 37 von 71
blue_PiraT2_UserManual_V2.4.1.doc
10 Interfaces
The different interfaces of the blue PiraT2 supported bus systems are described in this chapter
in more detail.
10.1 CAN
The blue PiraT2 is able to record data in compliance with the CAN specification 2.0a (11 Bit
identifier) and 2.0b (29 Bit identifier).
10.1.1
High Speed and Low Speed operating modes
Depending on the model, the blue PiraT2 has different numbers of High Speed (HS) and Low
Speed (LS) CAN interfaces. It is not possible to change a CAN interface from Low to High
Speed or vice versa. Each type is using different transceivers.
The electrical behavior of the Low Speed and the High Speed CAN is different, hence, the Low
Speed CAN port of the blue PiraT2 must not be connected to a High Speed CAN bus and vice
versa.
Both operating modes use differential signals (CANH, CANL). For the correct data recording, all
nodes of the bus must have a common reference potential. The blue PiraT2 uses the connec-
tion
“
clamp 31
” as a reference potential. The lines of the High Speed CANs are terminated with
a high resistance.
Low Speed CAN
High Speed CAN
Transceiver chip
Philips TJA1054
Philips TJA1041
Terminating resistor
12k
2k6
Baud rate
50 kbit/s - 125 kbit/s
50 kbit/s - 1 Mbit/s
Supported identifiers (SW)
11 and 29 Bit
11 and 29 Bit
Disabling acknowledge
possible
possible
Time stamps
at the end of the telegram
at the end of the telegram
Table 10.1: CAN
10.1.2
CAN data with 29 Bit identifiers
The blue PiraT2 can also log CAN data with 29
Bit identifiers. You don’t have to configure any-
thing. All the CAN data will be logged as they are available on the CAN bus. It is also possible
to log CAN messages mixed with 11 Bit and 29 Bit identifiers.
