RP 1210

Brief introduction to RP1210

RP 1210 is a proven programming interface initiated through the “Recommended Engineering and Maintenance Practice” of the Technology & Maintenance Council (TMC) and the American Trucking Associations (ATA). This interface primarily enables access to vehicle communication interfaces (VCIs) in the truck sector. RP 1210 allows access to J1708/J1587, CAN, J1939, and J1850 bus systems. Key use cases include programming, diagnostics, and analysis. Much like SAE J2534, the diagnostic interface can be used independently of the OEM—a clear advantage for workshops.

Overview

The following diagram shows a simplified workflow of how an application uses RP1210:

RP1210_SendMessage transfers a byte buffer to the RP1210 library. The application is responsible for ensuring that the buffer content is in the format appropriate for the protocol. For ISO15765, for example, the format is as follows:
1 byte (Message Type) + 4 bytes (CAN ID) + 1 byte (Extended Address) + (0–4096) message bytes

RP1210_ReadMessage returns a byte buffer, the format of which depends on the protocol. For ISO15765, the following information is added to the beginning of the buffer in addition to the format described above:
4 bytes (time stamp) + 0/1 (echo) + 1 byte (indication status)

Echo: when enabled, indicates whether the client originally sent the message. If echo mode is disabled, this byte is not present.
Indication Status: Message acknowledged, error occurred, first message of a segment (first frame of a multi-frame message).

The API offers the following functions:

Function	Description
RP1210_ClientConnect	Establishing a logical connection to the RP 1210 DLL.
RP1210_ClientDisconnect	Terminating the logical connection to the RP 1210 DLL.
RP1210_SendMessage	Sends a message to the RP 1210 DLL.
RP1210_ReadMessage	Reads a message from the RP 1210 DLL.
RP1210_SendCommand	Sends a command to the RP 1210 DLL.
RP1210_GetErrorMsg	Translates an RP 1210 error code into text.
RP1210_GetLastErrorMsg	Translates an RP 1210 error code into a more detailed text.
RP1210_GetHardwareStatus	Returns the connection status.
RP1210_ReadVersion	Reads the version information of the RP 1210 API DLL via the API.
RP1210_ReadDetailedVersion	Reads the version information of the RP 1210 API DLL via the API (new preferred version).
RP1210_Ioctl	Used to change the status of vehicle communication. This was introduced in RP1210B and is currently used by RP1210 only for ISO9141 and KWP2000 communication. This function enables the future development of RP1210 to support additional automotive protocols.

Features

• Multiple client applications can access the same vehicle bus in parallel.
• It is the task of the client application to assign the messages to the corresponding control units.
• Pure C API with 11 functions
• Error Handling by Evaluating Return Values (No Exceptions)
• Specified primarily for Windows

Since RP 1210 is a relatively simple programming interface, a large part of the logic must be handled by the application itself.

Integration into an Application

Every RP 1210 installation includes an .INI file and a .DLL file. The RP 1210 specification mandates the format for the filenames and their paths.

File type	Installation path	File name
INI	GetSystemWindowsDirectory – WIN API	VENDRX32.ini
DLL	GetSystemDirectory() – WIN API	VENDRX32.dll

VENDRX is the manufacturer name of the interface.