train.rbc_ertms_wire Namespace Reference

Classes
class	ErtmsDecodeError

Functions
	_pack_position_report (pos)
	_unpack_position_report (buf, offset)
	_finalize (nid_message, body_after_header, nid_engine, t_train)
	encode_msg_155 (nid_engine, t_train=0)
	encode_msg_156 (nid_engine, t_train=0)
	encode_msg_159 (nid_engine, m_version, t_train=0)
	encode_msg_146 (nid_engine, t_train_ack, t_train=0)
	encode_msg_136 (nid_engine, position_report, t_train=0)
	encode_msg_136_packet1 (nid_engine, packet1_report, t_train=0)
	encode_msg_132 (nid_engine, q_marqstreason, position_report, t_train=0)
	encode_msg_129 (nid_engine, position_report, l_train, v_maxtrain, m_loadinggauge, m_axleload, m_airtight, t_train=0)
	encode_msg_130 (nid_engine, position_report, t_train=0)
	encode_msg_147 (nid_engine, nid_em, q_emergency_stop, position_report, t_train=0)
	encode_msg_150 (nid_engine, position_report, t_train=0)
	encode_msg_154 (nid_engine, t_train=0)
	encode_msg_157 (nid_engine, q_status, position_report, t_train=0)
	encode_msg_158 (nid_engine, nid_textmessage, position_report, t_train=0)
	_decode_header_c2t (buf)
	decode_msg_3 (buf)
	decode_msg_24 (buf)
	decode (buf)

Variables
int	MSG_VALIDATED_TRAIN_DATA = 129
int	MSG_REQUEST_FOR_SHUNTING = 130
int	MSG_MA_REQUEST = 132
int	MSG_POSITION_REPORT = 136
int	MSG_ACKNOWLEDGEMENT = 146
int	MSG_ACK_EMERGENCY_STOP = 147
int	MSG_INIT_SESSION = 155
int	MSG_TERMINATE_SESSION = 156
int	MSG_SESSION_ESTABLISHED = 159
int	MSG_MOVEMENT_AUTHORITY = 3
int	MSG_UNCONDITIONAL_EMERGENCY_STOP = 16
int	MSG_REVOCATION_EMERGENCY_STOP = 18
int	MSG_GENERAL_MESSAGE = 24
int	PACKET_NATIONAL_VALUES = 3
int	PACKET_LINKING_INFO = 5
int	PACKET_LEVEL_2_3_MA = 15
int	PACKET_GRADIENT_PROFILE = 21
int	PACKET_STATIC_SPEED_PROFILE = 27
int	PACKET_MA_REQUEST_PARAMS = 57
int	PACKET_POSITION_REPORT_PARAMS = 58
int	PACKET_TEMPORARY_SPEED_RESTRICT = 65
int	PACKET_TSR_REVOCATION = 66
int	PACKET_TEXT_MESSAGE = 72
	_HEADER_T2T = struct.Struct(">BHII")
	_HEADER_C2T = struct.Struct(">BHIBHH")
	_POSITION_REPORT = struct.Struct(">BHHIBBIIHBB")
	_POSITION_REPORT_PACKET1 = struct.Struct(">HHHHIHBB")
int	Q_SCALE_10CM = 0
int	Q_SCALE_1M = 1
int	Q_SCALE_10M = 2
int	Q_DIRLRBG_REVERSE = 0
int	Q_DIRLRBG_NOMINAL = 1
int	Q_DIRLRBG_UNKNOWN = 2
int	Q_DLRBG_REVERSE = 0
int	Q_DLRBG_NOMINAL = 1
int	Q_DLRBG_UNKNOWN = 2
int	PACKET_0_POSITION_REPORT = 0
int	PACKET_1_POSITION_REPORT_2BG = 1
dict	_DECODERS

Detailed Description

Real Subset-026 ERTMS message codec - Python mirror of
safeAPIRBC2oo2GP/src/application/AB/GP/ertms/train/ab_gp_ertms_train_codec.c
(byte shape and order only). Keep this file in exact sync with that C
file by hand; there is no shared schema between the two languages, same
"by-hand port, not a generated binding" precedent rbc_wire.py's own
module doc already states for the flat ADR-029 scheme.

**Deliberately a DIFFERENT wire shape from rbc_wire.py, not a variant of
it** - this is not an oversight, don't "fix" the two into consistency:
  - rbc_wire.py: one fixed 96-byte struct, little-endian, every field at
    a fixed offset regardless of kind - mirrors rbc_wire_types.h/
    rbc_wire.c's own flat ADR-029 envelope.
  - This module: real Subset-026 message-specific shapes, BIG-endian,
    genuinely variable length (optional packets each self-identify with
    their own leading NID_PACKET byte) - mirrors ab_gp_ertms_train_codec.c,
    a byte-aligned TLV codec (not literally the real spec's own sub-byte
    bit-packing - see that C file's own header doc for why: a deliberate,
    already-made MISRA-friendly simplification this module also follows).

Both scheme's bytes are wrapped identically at the TRANSPORT level by one
new envelope kind, RBC_MSG_ERTMS_ENVELOPE (rbc_wire_types.h) - see that
kind's own doc: byte 0 = the kind (22 - moved from 21 after a real
collision with this project's own flat TRAIN_CONNECT=21, see
rbc_wire_types.h's/rbc_messages.py's own comments), byte 1 = train_id, bytes 2..
= this module's own encode()/decode() output verbatim. rbc_messages.py's
MessageCatalog is what actually builds/parses that 2-byte prefix (its own
"ertms" wireFormat branch) - this module only ever sees/produces the
bytes AFTER that prefix, same "SimCore doesn't know kind numbers"
boundary rbc_wire.py's own module doc draws for the flat scheme.

Real NID_MESSAGE/NID_PACKET numbers only, never this project's own flat-
scheme project-specific numbering (rbc_wire.py's `kind` byte) - see
ab_gp_ertms_train_interface.h/ab_gp_ertms_train_packets.h for the C-side
`#define`s these mirror.

Function Documentation

_decode_header_c2t()

_decode_header_c2t ( buf )

protected

Definition at line 249 of file rbc_ertms_wire.py.

_finalize()

_finalize ( nid_message, body_after_header, nid_engine, t_train )

protected

Builds the full Train-to-Track frame and patches l_message with the
real total length, exactly matching
rbc_train_codec_encode_track_to_train()'s own "l_message computed
here, not caller-supplied" fix on the C side - never trust a
placeholder length, always the real encoded size.

Definition at line 130 of file rbc_ertms_wire.py.

_pack_position_report()

_pack_position_report ( pos )

protected

@param pos: dict with the full Packet 0 field set - q_scale, nid_c,
nid_bg, d_lrbg, q_dirlrbg, q_dlrbg, l_doubtover, l_doubtunder, v_train,
m_mode, m_level - matching rbc_packet_read_0_position_report()'s own
field order exactly (ab_gp_ertms_train_packet_codec.c).

Definition at line 108 of file rbc_ertms_wire.py.

_unpack_position_report()

_unpack_position_report ( buf, offset )

protected

Unused today (this sim only ENCODES Packet 0, as the message
originator - see _pack_position_report()'s own doc) - kept for
encode/decode symmetry with the rest of this module.

Definition at line 118 of file rbc_ertms_wire.py.

decode()

decode

(

buf

)

@return (nid_message, decoded_dict) by peeking buf[0], dispatching
to the matching decode_msg_*() above. Raises ErtmsDecodeError for an
empty buffer or an nid_message this module doesn't yet decode
(Msg 16/18 - Emergency Stop - have real C-side encoders already but
no Python decoder yet, out of scope for the SoM/Running/EoM flow).

Definition at line 399 of file rbc_ertms_wire.py.

decode_msg_24()

decode_msg_24

(

buf

)

Msg 24: General Message. @return dict with header and whichever of
Packet 3/57/58/65/66/72 were present - same has_X/X pairing
ab_gp_ertms_train_interface.h's own rbc_msg_24_general_message_t
struct uses.

Definition at line 324 of file rbc_ertms_wire.py.

decode_msg_3()

decode_msg_3

(

buf

)

Msg 3: Movement Authority. @return dict with header, ma (Packet 15,
always present), and optional gradient/ssp/linking (Packets 21/27/5) -
same has_X/X pairing ab_gp_ertms_train_interface.h's own
rbc_msg_3_movement_authority_t struct uses.

Definition at line 260 of file rbc_ertms_wire.py.

encode_msg_129()

encode_msg_129	(		nid_engine,
			position_report,
			l_train,
			v_maxtrain,
			m_loadinggauge,
			m_axleload,
			m_airtight,
			t_train = 0 )

Msg 129: Validated Train Data - Packet 0 then the flat train-data
fields (same field subset ab_gp_ertms_train_codec.c's own decode
reads).

Definition at line 197 of file rbc_ertms_wire.py.

encode_msg_130()

encode_msg_130	(		nid_engine,
			position_report,
			t_train = 0 )

Msg 130: Request for Shunting - Packet 0.

Definition at line 208 of file rbc_ertms_wire.py.

encode_msg_132()

encode_msg_132	(		nid_engine,
			q_marqstreason,
			position_report,
			t_train = 0 )

Msg 132: MA Request - Q_MARQSTREASON then Packet 0.

Definition at line 191 of file rbc_ertms_wire.py.

encode_msg_136()

encode_msg_136	(		nid_engine,
			position_report,
			t_train = 0 )

Msg 136: Train Position Report, Packet 0 - the normal active-mission
cadence. Real Subset-026 Msg 136 self-identifies which packet variant
it carries with a leading NID_PACKET byte (see
rbc_train_codec_decode_train_to_track()'s own Msg 136 case) - this
encoder writes PACKET_0_POSITION_REPORT then the Packet 0 body.

Definition at line 167 of file rbc_ertms_wire.py.

encode_msg_136_packet1()

encode_msg_136_packet1	(		nid_engine,
			packet1_report,
			t_train = 0 )

Msg 136: Train Position Report, Packet 1 (2-balise-group variant) -
the post-EoM idle heartbeat cadence (see train_sim.py's own post-EoM
phase tracking). @param packet1_report: dict with nid_c, nid_bg,
prv_nid_c, prv_nid_bg, d_lrbg, v_train, m_mode, m_level - same field
set read_position_report_packet1() reads on the C side.

Definition at line 177 of file rbc_ertms_wire.py.

encode_msg_146()

encode_msg_146	(		nid_engine,
			t_train_ack,
			t_train = 0 )

Msg 146: Acknowledgement - real Subset-026 146 acks by TIMESTAMP of
the acked message, not a sequence number (see message_catalog.json's
own _subset026Reference comment on this).

Definition at line 160 of file rbc_ertms_wire.py.

encode_msg_147()

encode_msg_147	(		nid_engine,
			nid_em,
			q_emergency_stop,
			position_report,
			t_train = 0 )

Msg 147: Ack Emergency Stop - NID_EM, Q_EMERGENCY_STOP then Packet 0.

Definition at line 213 of file rbc_ertms_wire.py.

encode_msg_150()

encode_msg_150	(		nid_engine,
			position_report,
			t_train = 0 )

Msg 150: End of Mission - Packet 0.

Definition at line 219 of file rbc_ertms_wire.py.

encode_msg_154()

encode_msg_154	(		nid_engine,
			t_train = 0 )

Msg 154: No compatible version supported - header only.

Definition at line 224 of file rbc_ertms_wire.py.

encode_msg_155()

encode_msg_155	(		nid_engine,
			t_train = 0 )

Msg 155: Initiation of a Communication Session - header only.

Definition at line 145 of file rbc_ertms_wire.py.

encode_msg_156()

encode_msg_156	(		nid_engine,
			t_train = 0 )

Msg 156: Termination of a Communication Session - header only.

Definition at line 150 of file rbc_ertms_wire.py.

encode_msg_157()

encode_msg_157	(		nid_engine,
			q_status,
			position_report,
			t_train = 0 )

Msg 157: SoM Position Report - Q_STATUS then Packet 0.

Definition at line 229 of file rbc_ertms_wire.py.

encode_msg_158()

encode_msg_158	(		nid_engine,
			nid_textmessage,
			position_report,
			t_train = 0 )

Msg 158: Text Message Ack - NID_TEXTMESSAGE then Packet 0.

Definition at line 235 of file rbc_ertms_wire.py.

encode_msg_159()

encode_msg_159	(		nid_engine,
			m_version,
			t_train = 0 )

Msg 159: Session Established.

Definition at line 155 of file rbc_ertms_wire.py.

Variable Documentation

_DECODERS

dict train.rbc_ertms_wire._DECODERS

protected

Initial value:

=  {
    MSG_MOVEMENT_AUTHORITY: decode_msg_3,
    MSG_GENERAL_MESSAGE: decode_msg_24,
}

Definition at line 393 of file rbc_ertms_wire.py.

_HEADER_C2T

train.rbc_ertms_wire._HEADER_C2T = struct.Struct(">BHIBHH")

protected

Definition at line 69 of file rbc_ertms_wire.py.

_HEADER_T2T

train.rbc_ertms_wire._HEADER_T2T = struct.Struct(">BHII")

protected

Definition at line 68 of file rbc_ertms_wire.py.

_POSITION_REPORT

train.rbc_ertms_wire._POSITION_REPORT = struct.Struct(">BHHIBBIIHBB")

protected

Definition at line 78 of file rbc_ertms_wire.py.

_POSITION_REPORT_PACKET1

train.rbc_ertms_wire._POSITION_REPORT_PACKET1 = struct.Struct(">HHHHIHBB")

protected

Definition at line 79 of file rbc_ertms_wire.py.

MSG_ACK_EMERGENCY_STOP

int train.rbc_ertms_wire.MSG_ACK_EMERGENCY_STOP = 147

Definition at line 46 of file rbc_ertms_wire.py.

MSG_ACKNOWLEDGEMENT

int train.rbc_ertms_wire.MSG_ACKNOWLEDGEMENT = 146

Definition at line 45 of file rbc_ertms_wire.py.

MSG_GENERAL_MESSAGE

int train.rbc_ertms_wire.MSG_GENERAL_MESSAGE = 24

Definition at line 54 of file rbc_ertms_wire.py.

MSG_INIT_SESSION

int train.rbc_ertms_wire.MSG_INIT_SESSION = 155

Definition at line 47 of file rbc_ertms_wire.py.

MSG_MA_REQUEST

int train.rbc_ertms_wire.MSG_MA_REQUEST = 132

Definition at line 43 of file rbc_ertms_wire.py.

MSG_MOVEMENT_AUTHORITY

int train.rbc_ertms_wire.MSG_MOVEMENT_AUTHORITY = 3

Definition at line 51 of file rbc_ertms_wire.py.

MSG_POSITION_REPORT

int train.rbc_ertms_wire.MSG_POSITION_REPORT = 136

Definition at line 44 of file rbc_ertms_wire.py.

MSG_REQUEST_FOR_SHUNTING

int train.rbc_ertms_wire.MSG_REQUEST_FOR_SHUNTING = 130

Definition at line 42 of file rbc_ertms_wire.py.

MSG_REVOCATION_EMERGENCY_STOP

int train.rbc_ertms_wire.MSG_REVOCATION_EMERGENCY_STOP = 18

Definition at line 53 of file rbc_ertms_wire.py.

MSG_SESSION_ESTABLISHED

int train.rbc_ertms_wire.MSG_SESSION_ESTABLISHED = 159

Definition at line 49 of file rbc_ertms_wire.py.

MSG_TERMINATE_SESSION

int train.rbc_ertms_wire.MSG_TERMINATE_SESSION = 156

Definition at line 48 of file rbc_ertms_wire.py.

MSG_UNCONDITIONAL_EMERGENCY_STOP

int train.rbc_ertms_wire.MSG_UNCONDITIONAL_EMERGENCY_STOP = 16

Definition at line 52 of file rbc_ertms_wire.py.

MSG_VALIDATED_TRAIN_DATA

int train.rbc_ertms_wire.MSG_VALIDATED_TRAIN_DATA = 129

Definition at line 41 of file rbc_ertms_wire.py.

PACKET_0_POSITION_REPORT

int train.rbc_ertms_wire.PACKET_0_POSITION_REPORT = 0

Definition at line 104 of file rbc_ertms_wire.py.

PACKET_1_POSITION_REPORT_2BG

int train.rbc_ertms_wire.PACKET_1_POSITION_REPORT_2BG = 1

Definition at line 105 of file rbc_ertms_wire.py.

PACKET_GRADIENT_PROFILE

int train.rbc_ertms_wire.PACKET_GRADIENT_PROFILE = 21

Definition at line 60 of file rbc_ertms_wire.py.

PACKET_LEVEL_2_3_MA

int train.rbc_ertms_wire.PACKET_LEVEL_2_3_MA = 15

Definition at line 59 of file rbc_ertms_wire.py.

PACKET_LINKING_INFO

int train.rbc_ertms_wire.PACKET_LINKING_INFO = 5

Definition at line 58 of file rbc_ertms_wire.py.

PACKET_MA_REQUEST_PARAMS

int train.rbc_ertms_wire.PACKET_MA_REQUEST_PARAMS = 57

Definition at line 62 of file rbc_ertms_wire.py.

PACKET_NATIONAL_VALUES

int train.rbc_ertms_wire.PACKET_NATIONAL_VALUES = 3

Definition at line 57 of file rbc_ertms_wire.py.

PACKET_POSITION_REPORT_PARAMS

int train.rbc_ertms_wire.PACKET_POSITION_REPORT_PARAMS = 58

Definition at line 63 of file rbc_ertms_wire.py.

PACKET_STATIC_SPEED_PROFILE

int train.rbc_ertms_wire.PACKET_STATIC_SPEED_PROFILE = 27

Definition at line 61 of file rbc_ertms_wire.py.

PACKET_TEMPORARY_SPEED_RESTRICT

int train.rbc_ertms_wire.PACKET_TEMPORARY_SPEED_RESTRICT = 65

Definition at line 64 of file rbc_ertms_wire.py.

PACKET_TEXT_MESSAGE

int train.rbc_ertms_wire.PACKET_TEXT_MESSAGE = 72

Definition at line 66 of file rbc_ertms_wire.py.

PACKET_TSR_REVOCATION

int train.rbc_ertms_wire.PACKET_TSR_REVOCATION = 66

Definition at line 65 of file rbc_ertms_wire.py.

Q_DIRLRBG_NOMINAL

int train.rbc_ertms_wire.Q_DIRLRBG_NOMINAL = 1

Definition at line 92 of file rbc_ertms_wire.py.

Q_DIRLRBG_REVERSE

int train.rbc_ertms_wire.Q_DIRLRBG_REVERSE = 0

Definition at line 91 of file rbc_ertms_wire.py.

Q_DIRLRBG_UNKNOWN

int train.rbc_ertms_wire.Q_DIRLRBG_UNKNOWN = 2

Definition at line 93 of file rbc_ertms_wire.py.

Q_DLRBG_NOMINAL

int train.rbc_ertms_wire.Q_DLRBG_NOMINAL = 1

Definition at line 95 of file rbc_ertms_wire.py.

Q_DLRBG_REVERSE

int train.rbc_ertms_wire.Q_DLRBG_REVERSE = 0

Definition at line 94 of file rbc_ertms_wire.py.

Q_DLRBG_UNKNOWN

int train.rbc_ertms_wire.Q_DLRBG_UNKNOWN = 2

Definition at line 96 of file rbc_ertms_wire.py.

Q_SCALE_10CM

int train.rbc_ertms_wire.Q_SCALE_10CM = 0

Definition at line 88 of file rbc_ertms_wire.py.

Q_SCALE_10M

int train.rbc_ertms_wire.Q_SCALE_10M = 2

Definition at line 90 of file rbc_ertms_wire.py.

Q_SCALE_1M

int train.rbc_ertms_wire.Q_SCALE_1M = 1

Definition at line 89 of file rbc_ertms_wire.py.