Transmit

This page documents the transmit configuration.

The CANedge can be configured to automatically schedule and transmit a list of static messages. Each transmit message can be configured as either single-shot or periodic.

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Configuration file fields

This section is autogenerated from the Rule Schema file.

Transmit messages can.transmit

List of CAN bus messages transmitted by the device. Requires a CAN-bus physical mode supporting transmissions.

Type	Max items
array	64

Item can.transmit.item

Name can.transmit.item.name

Optional transmit message name.

Type	Max length
string	16

State can.transmit.item.state

Disabled transmit messages are ignored.

Type	Default	Options
integer	1	Disable: 0 Enable: 1

ID Format can.transmit.item.id_format

ID format of the transmit message.

Type	Default	Options
integer	0	Standard (11-bit): 0 Extended (29-bit): 1

Frame format can.transmit.item.frame_format

Frame format of the transmit message.

Type	Default	Options
integer	0	Standard: 0 Standard RTR: 2 FD: 1

Bit-Rate Switch can.transmit.item.brs

Determines if an FD message is transmitted using a switched bit-rate.

Type	Default
integer	0

Include in log can.transmit.item.log

Determines if the transmitted message is included in the log file.

Type	Default	Options
integer	0	Disable: 0 Enable: 1

Period (10 ms steps) can.transmit.item.period

Time period of the message transmission. 0: single shot, >0: periodic. Unit is ms.

Type	Minimum	Maximum	Multiple of
integer	0	4294967290	10

Delay (10 ms steps) can.transmit.item.delay

Offset message within the period or delay a single shot message. If multiple messages are transmitted by the device, it is recommended to offset each separately to reduce peak load on bus. If period > 0, delay < period. If single-shot, delay can be up to max value. Unit is ms.

Type	Minimum	Maximum	Multiple of
integer	0	4294967290	10

Message ID (hex) can.transmit.item.id

ID of message to transmit in hex. Example: 1FF.

Type
string

Messages Data (hex) can.transmit.item.data

Data bytes of message to transmit. RTR frames only use the number of bytes do determine the DLC. Example: 01020304 or 0102030405060708.

Type	Max length
string	128

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Configuration explained

This section contains additional information and examples.

Period and delay

Transmit messages can be configured as either single-shot or periodic.

The period value determines if a message is single-shot (0) or periodic (>0). The interpretation of the delay value depends on whether the message is single-shot or periodic (see more below).

Note

When possible, it is recommended to spread multiple transmit messages in time by using the delay value.

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Single-shot

A transmit message is single-shot when the period is set to 0. In this case, the delay is the time between boot-up1 and the single-shot transmission. Delaying a single-shot message can be useful if e.g. the receiving node has a long boot-up time. The maximum value allows for a delay of up to several hours.

Example: Four single-shot transmit messages are configured with different delay values.

#	Period [ms]	Delay [ms]
A	0	0
B	0	20
C	0	40
D	0	60

Below figure illustrates the transmission scheduling (arrow-heads symbolize transmissions).

Note

Note how the transmissions do not coincidence.

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Periodic

A transmit message is periodic when the period value is more than zero. In this case, the delay is the time from the start of each period to the transmission (the offset within the period). Consequently, the delay value must be less than the period value.

Example: Four periodic transmit messages are configured with delay values set to zero.

#	Period [ms]	Delay [ms]
A	10	0
B	20	0
C	30	0
D	40	0

Below figure illustrates the transmission scheduling (arrow-heads symbolize transmissions).

Note

Note how the transmissions periodically coincide in time. Avoid this by using delay values.

Example: Four periodic transmit messages are configured with the same period value and different delay values.

#	Period [ms]	Delay [ms]
A	40	0
B	40	10
C	40	20
D	40	30

Below figure illustrates the transmission scheduling (arrow-heads symbolize transmissions).

Note

Note how the transmissions do not coincidence.

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1

The single-shot delay starts from when the internal transmission scheduling starts shortly after power is applied.