/**
* Add an event source for an SCPI device.
*
+ * @param session The session to add the event source to.
* @param scpi Previously initialized SCPI device structure.
* @param events Events to check for.
* @param timeout Max time to wait before the callback is called, ignored if 0.
/**
* Remove event source for an SCPI device.
*
+ * @param session The session to remove the event source from.
* @param scpi Previously initialized SCPI device structure.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or