Fetch data from a storage station

Data stored in a ProviewR storage station can be fetched by the client interface sevcli.
First you initiate sevcli with sevcli_init() and state which storage station you want to
fetch the data from with sevcli_set_servernode().

sevcli_tCtx sevctx;

char server_node[40] = "MyStorageStation";

if ( !sevcli_init( &sts, &sevctx))

    throw co_error(sts);

if ( !sevcli_set_servernode( &sts, sevctx, server_node))

    throw co_error(sts);

Then you can fetch data with sevcli_get_itemdata(). Data is identified by object identity and
attribute name. You also state the time range for the data that is to be fetched and
maximum number of points.

pwr_tTime *time_buf;

void *value_buf;

pwr_tTime from = pwr_cNTime;

pwr_tTime to = pwr_cNTime;

int rows;

pwr_eType vtype;

unsigned int vsize;

pwr_tOName name = "H1-H2-Temperature";

pwr_tOName aname = "ActualValue";

pwr_tObjid oid;

char timstr[40];

sts = gdh_NameToObjid( name, &oid);

if (EVEN(sts)) throw co_error(sts);

if ( !sevcli_get_itemdata( &sts, sevctx, oid, aname, from, to, 1000, &time_buf, &value_buf,

                                                      &rows, &vtype, &vsize))

    throw co_error(sts);

for ( int i = 0; i < rows; i++) {

    time_AtoAscii( &time_buf[i], time_eFormat_DateAndTime, timstr, sizeof(timstr));

    cout << timstr << " " << ((pwr_tFloat32 *)value_buf)[i] << endl;

free( time_buf);

free( value_buf);

Finally you call sevcli_close() to disconnect the server node.

sevcli_close( &sts, sevctx);