Useful definitions for the traction modem. More...

#include <TractionModemDefs.hxx>

Classes
struct	CRC

struct	Header
	The header of a message. More...

struct	Message
	The definition of a message. More...

Public Types
enum	Command : uint16_t { CMD_PING = 0x0000 , CMD_NOP = 0x0001 , CMD_REBOOT = 0x0002 , CMD_BAUD_RATE_QUERY = 0x0003 , CMD_BAUD_RATE_REQUEST = 0x0004 , CMD_SPEED_SET = 0x0100 , CMD_FN_SET = 0x0101 , CMD_ESTOP_SET = 0x0102 , CMD_SPEED_QUERY = 0x0110 , CMD_FN_QUERY = 0x0111 , CMD_DC_DCC_PRESENT = 0x0200 , CMD_WIRELESS_PRESENT = 0x0201 , CMD_MEM_R = 0x1000 , CMD_MEM_W = 0x1001 , RESP_PING = RESPONSE \| CMD_PING , RESP_BAUD_RATE_QUERY = RESPONSE \| CMD_BAUD_RATE_QUERY , RESP_SPEED_SET = RESPONSE \| CMD_SPEED_SET , RESP_FN_SET = RESPONSE \| CMD_FN_SET , RESP_ESTOP_SET = RESPONSE \| CMD_ESTOP_SET , RESP_SPEED_QUERY = RESPONSE \| CMD_SPEED_QUERY , RESP_FN_QUERY = RESPONSE \| CMD_FN_QUERY , RESP_DC_DCC_PRESENT = RESPONSE \| CMD_DC_DCC_PRESENT , RESP_WIRELESS_PRESENT = RESPONSE \| CMD_WIRELESS_PRESENT , RESP_MEM_R = RESPONSE \| CMD_MEM_R , RESP_MEM_W = RESPONSE \| CMD_MEM_W }
	Command values. More...

using	Payload = std::string

Static Public Member Functions
static Payload	get_wireless_present_payload (bool is_present)
	Computes payload for the wireless present message.

static Payload	get_fn_set_payload (unsigned fn, uint16_t value)
	Computes payload to set a function.

static Payload	get_speed_set_payload (openlcb::Velocity v)
	Computes payload to set speed and direction.

static Payload	get_estop_payload ()
	Computes payload to set estop.

static Payload	get_memr_payload (uint8_t space, uint32_t address, uint8_t count)
	Computes payload to read some data.

static Payload	get_memw_payload (uint8_t space, uint32_t address, const std::string &data)
	Computes payload to write some data.

static Payload	get_memw_payload (uint8_t space, uint32_t address, const uint8_t *buf, size_t count)
	Computes payload to write some data.

static void	append_uint32 (Payload *p, uint32_t v)
	Appends an uint32_t in network byte order to the payload.

static void	append_uint16 (Payload *p, uint16_t v)
	Appends an uint16_t in network byte order to the payload.

static void	append_uint8 (Payload *p, uint8_t v)
	Appends an uint8_t to the payload.

static void	prepare (Payload *p, Command cmd, uint16_t len)
	Prepares the header of a packet.

static void	append_crc (Payload *p)
	Computes and appends the CRC to the payload.

static uint32_t	get_uint32 (const Payload &p, unsigned ofs)
	Extract uint32_t value from a given offset in a wire formatted payload.

static uint16_t	get_uint16 (const Payload &p, unsigned ofs)
	Extract uint16_t value from a given offset in a wire formatted payload.

static const CRC	get_crc (const Payload &p, uint16_t length)
	Extract the CRC value(s) from a given payload.

static bool	is_valid (const Payload &p)
	Verifies that a given payload is a valid packet.

Static Public Attributes
static constexpr uint32_t	PREAMBLE = 0x41d2c37a
	Every command starts with these bytes.

static constexpr char	PREAMBLE_FIRST = 0x41
	First byte of the preamble.

static constexpr uint16_t	RESPONSE = 0x8000
	The most significant bit of each command means "response" to a previous message.

static constexpr unsigned	LEN_HEADER = 4+2+2
	Length of a the header. 4 bytes preamble, 2 bytes cmd, 2 bytes length.

static constexpr unsigned	LEN_BASE = 14
	Length of a zero-payload packet.

static constexpr unsigned	LEN_FN_SET = 6
	Length of the data payload of a set function packet.

static constexpr unsigned	LEN_SPEED_SET = 1
	Length of the data payload of a set speed packet.

static constexpr unsigned	LEN_ESTOP_SET = 0
	Length of the data payload of a set estop packet.

static constexpr unsigned	LEN_WIRELESS_PRESENT = 1
	Length of the data payload of a wireless present packet.

static constexpr unsigned	LEN_MEM_R = 6
	Length of the data payload of a set estop packet.

static constexpr unsigned	LEN_MEM_W = 5
	Base length of the data, add the number of payload bytes.

static constexpr unsigned	MAX_LEN = 512
	Maximum allowed len value.

static constexpr unsigned	OFS_CMD = 4
	Offset of the command in the packet.

static constexpr unsigned	OFS_LEN = 6
	Offset of the length in the packet.

static constexpr unsigned	OFS_DATA = 8
	Offset of the first data byte in the packet.

Detailed Description

Useful definitions for the traction modem.

Definition at line 46 of file TractionModemDefs.hxx.

Member Typedef Documentation

◆ Payload

using traction_modem::Defs::Payload = std::string

Definition at line 48 of file TractionModemDefs.hxx.

Member Enumeration Documentation

◆ Command

enum traction_modem::Defs::Command : uint16_t

Command values.

Enumerator
CMD_PING	ping
CMD_NOP	no-operation (do nothing)
CMD_REBOOT	reboot request
CMD_BAUD_RATE_QUERY	query the supported baud rates
CMD_BAUD_RATE_REQUEST	request a specific baud rate
CMD_SPEED_SET	set velocity
CMD_FN_SET	set function
CMD_ESTOP_SET	emergency stop request
CMD_SPEED_QUERY	query current speed
CMD_FN_QUERY	query function status
CMD_DC_DCC_PRESENT	DC/DCC present.
CMD_WIRELESS_PRESENT	wireless present
CMD_MEM_R	memory read
CMD_MEM_W	memory write
RESP_PING	ping response
RESP_BAUD_RATE_QUERY	baud rate query response
RESP_SPEED_SET	set velocity response
RESP_FN_SET	set function response
RESP_ESTOP_SET	emergency stop response
RESP_SPEED_QUERY	query current speed response
RESP_FN_QUERY	query function status response
RESP_DC_DCC_PRESENT	DC/DCC present response.
RESP_WIRELESS_PRESENT	wireless present response
RESP_MEM_R	memory read response
RESP_MEM_W	memory write response

Definition at line 60 of file TractionModemDefs.hxx.

Member Function Documentation

◆ append_crc()

static void traction_modem::Defs::append_crc ( Payload * p )

inlinestatic

Computes and appends the CRC to the payload.

Parameters

p	wire formatted payload, including prepended preamble, to append to

Definition at line 322 of file TractionModemDefs.hxx.

◆ append_uint16()

static void traction_modem::Defs::append_uint16	(	Payload *	p,
		uint16_t	v
	)

inlinestatic

Appends an uint16_t in network byte order to the payload.

Parameters

p	wire formatted payload to append to
v	value to append

Definition at line 293 of file TractionModemDefs.hxx.

◆ append_uint32()

static void traction_modem::Defs::append_uint32	(	Payload *	p,
		uint32_t	v
	)

inlinestatic

Appends an uint32_t in network byte order to the payload.

Parameters

p	wire formatted payload to append to
v	value to append

Definition at line 282 of file TractionModemDefs.hxx.

◆ append_uint8()

static void traction_modem::Defs::append_uint8	(	Payload *	p,
		uint8_t	v
	)

inlinestatic

Appends an uint8_t to the payload.

Parameters

p	wire formatted payload to append to
v	value to append

Definition at line 302 of file TractionModemDefs.hxx.

◆ get_crc()

static const CRC traction_modem::Defs::get_crc	(	const Payload &	p,
		uint16_t	length
	)

inlinestatic

Extract the CRC value(s) from a given payload.

The assumption is that p contains a valid (correctly formatted) message. Additional partial or complete messages contained within p are ignored.

Parameters

p	wire formatted payload
length	length field from the Header in host endianess (length in bytes of the message data)

Definition at line 368 of file TractionModemDefs.hxx.

◆ get_estop_payload()

static Payload traction_modem::Defs::get_estop_payload ( )

inlinestatic

Computes payload to set estop.

Returns: wire formatted payload

Definition at line 222 of file TractionModemDefs.hxx.

◆ get_fn_set_payload()

static Payload traction_modem::Defs::get_fn_set_payload	(	unsigned	fn,
		uint16_t	value
	)

inlinestatic

Computes payload to set a function.

Parameters

fn	function number
value	function value. For binary functions, 0 is off, 1 is on.

Returns: wire formatted payload

Definition at line 196 of file TractionModemDefs.hxx.

◆ get_memr_payload()

static Payload traction_modem::Defs::get_memr_payload	(	uint8_t	space,
		uint32_t	address,
		uint8_t	count
	)

inlinestatic

Computes payload to read some data.

Parameters

space	address space
address	address offset within address space
count	size of read data requested in bytes

Returns: wire formatted payload

Definition at line 236 of file TractionModemDefs.hxx.

◆ get_memw_payload() [1/2]

static Payload traction_modem::Defs::get_memw_payload	(	uint8_t	space,
		uint32_t	address,
		const std::string &	data
	)

inlinestatic

Computes payload to write some data.

Parameters

space	address space
address	address offset within address space
data	data to write

Returns: wire formatted payload

Definition at line 254 of file TractionModemDefs.hxx.

◆ get_memw_payload() [2/2]

static Payload traction_modem::Defs::get_memw_payload	(	uint8_t	space,
		uint32_t	address,
		const uint8_t *	buf,
		size_t	count
	)

inlinestatic

Computes payload to write some data.

Parameters

space	address space
address	address offset within address space
buf	data to write
count	size of data to write in bytes

Returns: wire formatted payload

Definition at line 266 of file TractionModemDefs.hxx.

◆ get_speed_set_payload()

static Payload traction_modem::Defs::get_speed_set_payload ( openlcb::Velocity v )

inlinestatic

Computes payload to set speed and direction.

Parameters

v	speed and direction data.

Returns: wire formatted payload

Definition at line 210 of file TractionModemDefs.hxx.

◆ get_uint16()

static uint16_t traction_modem::Defs::get_uint16	(	const Payload &	p,
		unsigned	ofs
	)

inlinestatic

Extract uint16_t value from a given offset in a wire formatted payload.

Parameters

p	wire formatted payload
ofs	byte offset to start from for extraction

Returns: extracted value

Definition at line 351 of file TractionModemDefs.hxx.

◆ get_uint32()

static uint32_t traction_modem::Defs::get_uint32	(	const Payload &	p,
		unsigned	ofs
	)

inlinestatic

Extract uint32_t value from a given offset in a wire formatted payload.

Parameters

p	wire formatted payload
ofs	byte offset to start from for extraction

Returns: extracted value

Definition at line 336 of file TractionModemDefs.hxx.

◆ get_wireless_present_payload()

static Payload traction_modem::Defs::get_wireless_present_payload ( bool is_present )

inlinestatic

Computes payload for the wireless present message.

Parameters

is_present true if "present", else false

Returns: wire formatted payload

Definition at line 182 of file TractionModemDefs.hxx.

◆ is_valid()

static bool traction_modem::Defs::is_valid ( const Payload & p )

inlinestatic

Verifies that a given payload is a valid packet.

This checks for the preamble and the length matching what is needed for the packet size. Does not check the CRC.

Parameters

p	wire formatted payload

Returns: true if valid, else false.

Definition at line 382 of file TractionModemDefs.hxx.

◆ prepare()

static void traction_modem::Defs::prepare	(	Payload *	p,
		Command	cmd,
		uint16_t	len
	)

inlinestatic

Prepares the header of a packet.

Parameters

p	packet buffer.
cmd	command to add to header.
len	length of data payload that will come after the header.

Definition at line 311 of file TractionModemDefs.hxx.

Member Data Documentation

◆ LEN_BASE

constexpr unsigned traction_modem::Defs::LEN_BASE = 14

staticconstexpr

Length of a zero-payload packet.

4 bytes preamble, 2 bytes cmd, 2 bytes length, 6 bytes CRC.

Definition at line 109 of file TractionModemDefs.hxx.

◆ LEN_ESTOP_SET

constexpr unsigned traction_modem::Defs::LEN_ESTOP_SET = 0

staticconstexpr

Length of the data payload of a set estop packet.

Definition at line 115 of file TractionModemDefs.hxx.

◆ LEN_FN_SET

constexpr unsigned traction_modem::Defs::LEN_FN_SET = 6

staticconstexpr

Length of the data payload of a set function packet.

Definition at line 111 of file TractionModemDefs.hxx.

◆ LEN_HEADER

constexpr unsigned traction_modem::Defs::LEN_HEADER = 4+2+2

staticconstexpr

Length of a the header. 4 bytes preamble, 2 bytes cmd, 2 bytes length.

Definition at line 105 of file TractionModemDefs.hxx.

◆ LEN_MEM_R

constexpr unsigned traction_modem::Defs::LEN_MEM_R = 6

staticconstexpr

Length of the data payload of a set estop packet.

Definition at line 119 of file TractionModemDefs.hxx.

◆ LEN_MEM_W

constexpr unsigned traction_modem::Defs::LEN_MEM_W = 5

staticconstexpr

Base length of the data, add the number of payload bytes.

Definition at line 121 of file TractionModemDefs.hxx.

◆ LEN_SPEED_SET

constexpr unsigned traction_modem::Defs::LEN_SPEED_SET = 1

staticconstexpr

Length of the data payload of a set speed packet.

Definition at line 113 of file TractionModemDefs.hxx.

◆ LEN_WIRELESS_PRESENT

constexpr unsigned traction_modem::Defs::LEN_WIRELESS_PRESENT = 1

staticconstexpr

Length of the data payload of a wireless present packet.

Definition at line 117 of file TractionModemDefs.hxx.

◆ MAX_LEN

constexpr unsigned traction_modem::Defs::MAX_LEN = 512

staticconstexpr

Maximum allowed len value.

Definition at line 124 of file TractionModemDefs.hxx.

◆ OFS_CMD

constexpr unsigned traction_modem::Defs::OFS_CMD = 4

staticconstexpr

Offset of the command in the packet.

Definition at line 127 of file TractionModemDefs.hxx.

◆ OFS_DATA

constexpr unsigned traction_modem::Defs::OFS_DATA = 8

staticconstexpr

Offset of the first data byte in the packet.

Definition at line 131 of file TractionModemDefs.hxx.

◆ OFS_LEN

constexpr unsigned traction_modem::Defs::OFS_LEN = 6

staticconstexpr

Offset of the length in the packet.

Definition at line 129 of file TractionModemDefs.hxx.

◆ PREAMBLE

constexpr uint32_t traction_modem::Defs::PREAMBLE = 0x41d2c37a

staticconstexpr

Every command starts with these bytes.

Definition at line 51 of file TractionModemDefs.hxx.

◆ PREAMBLE_FIRST

constexpr char traction_modem::Defs::PREAMBLE_FIRST = 0x41

staticconstexpr

First byte of the preamble.

Definition at line 53 of file TractionModemDefs.hxx.

◆ RESPONSE

constexpr uint16_t traction_modem::Defs::RESPONSE = 0x8000

staticconstexpr

The most significant bit of each command means "response" to a previous message.

Definition at line 57 of file TractionModemDefs.hxx.

The documentation for this struct was generated from the following file:

TractionModemDefs.hxx

Classes

Public Types

Static Public Member Functions

Static Public Attributes

Detailed Description

Member Typedef Documentation

◆ Payload

Member Enumeration Documentation

◆ Command

Member Function Documentation

◆ append_crc()

◆ append_uint16()

◆ append_uint32()

◆ append_uint8()

◆ get_crc()

◆ get_estop_payload()

◆ get_fn_set_payload()

◆ get_memr_payload()

◆ get_memw_payload() [1/2]

◆ get_memw_payload() [2/2]

◆ get_speed_set_payload()

◆ get_uint16()

◆ get_uint32()

◆ get_wireless_present_payload()

◆ is_valid()

◆ prepare()

Member Data Documentation

◆ LEN_BASE

◆ LEN_ESTOP_SET

◆ LEN_FN_SET

◆ LEN_HEADER

◆ LEN_MEM_R

◆ LEN_MEM_W

◆ LEN_SPEED_SET

◆ LEN_WIRELESS_PRESENT

◆ MAX_LEN

◆ OFS_CMD

◆ OFS_DATA

◆ OFS_LEN

◆ PREAMBLE

◆ PREAMBLE_FIRST

◆ RESPONSE