eReadNames [LJM User's Guide]

Read multiple device registers in one command, each register specified by name.

Syntax

LJM_ERROR_RETURN LJM_eReadNames(
int Handle,
int NumFrames,
const char ** aNames,
double * aValues,
int * ErrorAddress)

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.

NumFrames [in]

The total number of frames to access. A frame consists of one value, so the number of frames is the size of the aNames array.

aNames [in]

An array of names that specify the Modbus register(s) to write. Names can be found throughout the device datasheet or in the Modbus Map.

aValues [out]

An array of values received from the device. The array size should be same as the aNames array. The values will be converted into doubles automatically.

ErrorAddress [out]

If error, the address responsible for causing an error.

Returns

LJM errorcodes or 0 for no error.

Remarks

This function is commonly used to read a handful of values at once, and is more convenient than LJM_eReadAddresses because it is not necessary to know the data type.

Example

Reading analog inputs 5, 6, and 10.

C

int LJMError;
int errorAddress;
const char * aNames[3] = {"AIN5", "AIN6", "AIN10"};
double ainValues[3];
double ain5;
double ain6;
double ain10;

// handle comes from LJM_Open()
LJMError = LJM_eReadNames(handle, 3, aNames, ainValues, &errorAddress);
if (LJMError != LJME_NOERROR) {
    // Deal with error
}
ain5 = ainValues[0];
ain6 = ainValues[1];
ain10 = ainValues[2];