USERCANWRITE

Write frames to a CAN port

Platform:

OEM719, OEM729, OEM7700, OEM7720, PwrPak7, CPT7, CPT7700, SMART7

Use this command to write a basic CAN frame to the specified CAN port. The USERCANSTATUS log can be used to check the completion or status of the operation. An optional user defined Transaction ID can be provided to help synchronize requests with responses in the USERCANSTATUS log.

This command is primarily intended to be used by Lua applications that need to interact with external devices. See NovAtel API for information about creating Lua applications on OEM7 receivers.

Writing a CAN frame requires a Port ID, which indicates the CAN bus to write to; a identifier type (STANDARD or EXTENDED) and an identifier number. The operation can be set as "blocked" (TimeOutMS > 0) or "non-blocked" (TimeOutMS == 0). If set to "blocked", the operation will wait a certain period of time for a slot in the TX FIFO buffer. For system health reasons, there is no option for the operation to be blocked indefinitely.

Message ID: 2255

Syntax:

USERCANWRITE PortID MessageType MessageID Datalength Data [TimeOutMS] [TransactionID]

Abbreviated ASCII Examples:

USERCANWRITE CAN1 STD 123 8 3132333435363738 12 1234

USERCANWRITE CAN2 EXT 1767 3 ABCDED

Field	Field Type	ASCII Value	Binary Value	Description	Format	Binary Bytes	Binary Offset
1	Command header	–	–	USERCANWRITE header This field contains the command name for abbreviated ASCII or the message header for ASCII (see page 1) or Binary (see page 1).	–	Header	0
2	PortID	CAN1	1	The CAN port Identifier.	Enum	4	H
		CAN2	2
3	MessageType	STD	1	Standard message	Enum	4	H+4
		EXT	2	Extended message
4	MessageID			The Standard message ID has 11 bits. The Extended message ID has 29 bits.	HexUlong	4	H+8
5	Datalength	0 to 8		The length of data to be written in bytes.	Ulong	4	H+12
6	Data			The data to be written. The number of bytes in this data block must match the DataLength. In particular, when DataLength is 0, this field is empty. For ASCII and Abbreviated ASCII commands, this field is a hexadecimal string of two digits for each byte in the data block. There is no 0x prefix and spaces are not allowed in the string. Data is streamed to the device as a series of bytes in the order provided.	UChar Array	N1 In the binary command/log case, additional bytes of padding are added after this field to maintain 4-byte alignment for the fields that follow.	H+16
7	TimeOutMS	0 to 5000		The number of milliseconds for the operation to timeout. Default is 0. If set to 0, there is no wait for a free slot in the TX FIFO. If no slot is available, the data drops and a flag is set in USERCANSTATUS log. Maximum value is 5000.	Ulong	4	H+16+4*INT((N+3)/4)
8	TransactionID			An optional user provided ID for this transaction. Default = 0. This transaction ID is copied to the USERCANSTATUS log created for this write operation.	Ulong	4	H+20+4*INT((N+3)/4)