FD Bit rate Parameter Definitions

PCAN-Basic

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PCAN-Basic Documentation

Defines the different configuration parameters used to create a Flexible Data rate string for FD capable PCAN-Channels initialization. These values are used as parameter with CAN_InitializeFD (class-method: InitializeFD).

Clock Frequency parameters:

Type	Constant	Value	Description
String	PCAN_BR_CLOCK	"f_clock"	Clock frequency in Hertz (80000000, 60000000, 40000000, 30000000, 24000000, 20000000).
String	PCAN_BR_CLOCK_MHZ	"f_clock_mhz"	Clock frequency in Megahertz (80, 60, 40, 30, 24, 20).

Nominal Bit rate parameters:

Type	Constant	Value	Description
String	PCAN_BR_NOM_BRP	"nom_brp"	Clock prescaler for nominal time quantum (1..1024).
String	PCAN_BR_NOM_TSEG1	"nom_tseg1"	TSEG1 segment for nominal bit rate in time quanta (1..256).
String	PCAN_BR_NOM_TSEG2	"nom_tseg2"	TSEG2 segment for nominal bit rate in time quanta (1..128).
String	PCAN_BR_NOM_SJW	"nom_sjw"	Synchronization Jump Width for nominal bit rate in time quanta (1..128).

Data Bit rate parameters:

Type	Constant	Value	Description
String	PCAN_BR_DATA_BRP	"data_brp"	Clock prescaler for fast data time quantum (1..1024).
String	PCAN_BR_DATA_TSEG1	"data_tseg1"	TSEG1 segment for fast data bit rate in time quanta (1..32).
String	PCAN_BR_DATA_TSEG2	"data_tseg2"	TSEG2 segment for fast data bit rate in time quanta (1..16).
String	PCAN_BR_DATA_SJW	"data_sjw"	Synchronization Jump Width for fast data bit rate in time quanta (1..16).

Remarks

These definitions are constants values in an object oriented environment (Delphi, .NET Framework) and declared as defines in C++ (plain API).

Following points are to be respected in order to construct a valid FD Bit rate string:

The string must contain only one of the two possible "Clock Frequency" parameters, depending on the unit used (Hz, or MHz).
The frequency to use must be one of the 6 listed within the "Clock Frequency" parameters.
The value for each parameter must be separated with a '='. Example: "data_brp=1"
Each pair of parameter/value must be separated with a ','. Blank spaces are allowed but are not necessary. Example: "f_clock_mhz=24, nom_brp=1,"
Both Bit rates, or only the nominal one, must be defined within the string (PCAN_BR_DATA_* and PCAN_BR_NOM_*, or only PCAN_BR_NOM_*).

Example with nominal Bit rate only:

A valid string representing 1 Mbit/sec for both, nominal and data Bit rates:

"f_clock_mhz=20, nom_brp=5, nom_tseg1=2, nom_tseg2=1, nom_sjw=1"

Example with nominal and data Bit rate:

A valid string representing 1 Mbit/sec for nominal Bit rate, and 2 Mbit/sec for data Bit rate:

"f_clock_mhz=20, nom_brp=5, nom_tseg1=2, nom_tseg2=1, nom_sjw=1, data_brp=2, data_tseg1=3, data_tseg2=1, data_sjw=1"

Parameter Value Ranges:

Parameter	Value Range
f_clock	[80000000, 60000000, 40000000, 30000000, 24000000, 20000000]
f_clock_mhz	[80, 60, 40, 30, 24, 20]
nom_brp	1 .. 1024
nom_tseg1	1 .. 256
nom_tseg2	1 .. 128
nom_sjw	1 .. 128
data_brp	1 .. 1024
data_tseg1	1 .. 32
data_tseg2	1 .. 16
data_sjw	1 .. 16

Python:

The definitions of these values have the following form: TPCANBitrateFD(string) where string is the value contained in the "value" column. e.g. PCAN_BR_CLOCK is defined as TPCANBitrateFD("f_clock").