This double call was causing the following error:
sr: scpi_usbtmc: USBTMC bulk in transfer error: LIBUSB_ERROR_TIMEOUT.
* return VOLT/CURR. We always return a GVariant string in
* the Rigol notation.
*/
- if ((ret = sr_scpi_get_string(sdi->conn, NULL, &s)) != SR_OK)
- return ret;
+ s = g_variant_get_string(*data, NULL);
if (!strcmp(s, "CV") || !strcmp(s, "VOLT")) {
*data = g_variant_new_string("CV");
} else if (!strcmp(s, "CC") || !strcmp(s, "CURR")) {