Transmit

This page documents the transmit configuration.

The CANmod.router 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 phy.can_s1.transmit

List of scheduled transmit messages.

Type	Min items	Max items
array	0	16

Item phy.can_s1.transmit.item

Name phy.can_s1.transmit.item.name

Message name (optional).

Type	Max length
string	16

State phy.can_s1.transmit.item.state

Message state.

Type	Default	Options
integer	1	Disable: 0 Enable: 1

ID Format phy.can_s1.transmit.item.id_format

Message identifier format.

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

Frame format phy.can_s1.transmit.item.frame_format

Message frame format.

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

Bit-Rate Switch phy.can_s1.transmit.item.brs

Message data bit-rate-switch (FD only).

Type	Default
integer	0

Period (10 ms steps) phy.can_s1.transmit.item.period

Message schedule period in milliseconds. 0: single shot, >0: periodic.

Type	Minimum	Maximum	Multiple of
integer	0	4294967290	10

Delay (10 ms steps) phy.can_s1.transmit.item.delay

Message schedule offset in milliseconds. 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.

Type	Minimum	Maximum	Multiple of
integer	0	4294967290	10

Message ID (hex) phy.can_s1.transmit.item.id

Message identifier. Example: 1FF.

Type
string

Messages Data (hex) phy.can_s1.transmit.item.data

Message data bytes. For RTR frames, 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. Configuring multiple messages to transmit at the same time can result in messages not being transmitted.

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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-up[1] 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.