2.9.2 - Raw Byte Functions

Raw Byte Functions Overview

These functions do not provide full device synchronization within LJM. They are provided for advanced users familiar with Modbus that want to control the exact bytes sent/received.

2.9.2.1 - ReadRaw

Attempts to receive unaltered bytes from a device.

Syntax

LJM_ERROR_RETURN LJM_ReadRaw(
                      int Handle,
                      unsigned char * Data,
                      int NumBytes)

Parameters

Handle [in]: A device handle. The handle is a connection ID for an active device. Generate a handle with LJM_Open or LJM_OpenS.

Data [Out]: Buffer to be filled with bytes from the read

NumBytes [out]: The number of bytes that were read, or -1 for error.

Returns

LJM errorcode or 0 for no error.

Remarks

Must be used in conjunction with LJM_WriteRaw.

2.9.2.2 - WriteRaw

Attempts to send unaltered bytes to a device.

Syntax

LJM_ERROR_RETURN LJM_WriteRaw(
                      int Handle,
                      const unsigned char * Data,
                      int NumBytes)

Parameters

Handle [in]: A device handle. The handle is a connection ID for an active device. Generate a handle with LJM_Open or LJM_OpenS.

Data [in]: Buffer of bytes to send to the device.

NumBytes [in]: The number of bytes in Data.

Returns

LJM errorcode or 0 for no error.

Remarks

Must be used in conjunction with LJM_ReadRaw.