Since the operation for USB INSTR must retain knowledge of service request notifications, viReadSTB() a vendor MAY implement either a queue of status bytes from previous notifications or a single cached status byte, where each received status byte is bit-ORed into the single cached status byte. 6.1.9 viClear(vi) Purpose Clear a device. Parameters Name Direction Type Description vi IN ViSession Unique logical identifier to a session. Return Values This is the operational return status. It returns either a Type ViStatus completion code or an error code as follows. Completion Code Description VI_SUCCESS Operation completed successfully. Error Codes Description VI_ERROR_INV_SESSION The given session or object reference is invalid (both VI_ERROR_INV_OBJECT are the same value). VI_ERROR_NSUP_OPER The given does not support this operation. vi VI_ERROR_RSRC_LOCKED Specified operation could not be performed because the resource identified by has been locked for this vi kind of access. VI_ERROR_TMO Timeout expired before operation completed. VI_ERROR_RAW_WR_PROT_VIOL Violation of raw write protocol occurred during transfer. VI_ERROR_RAW_RD_PROT_VIOL Violation of raw read protocol occurred during transfer. VI_ERROR_BERR Bus error occurred during transfer. VI_ERROR_NCIC The interface associated with the given is not vi currently the controller in charge. VI_ERROR_NLISTENERS No Listeners condition is detected (both and NRFD are deasserted). NDAC VI_ERROR_INV_SETUP Unable to start operation because setup is invalid (due to attributes being set to an inconsistent state). VI_ERROR_CONN_LOST The I/O connection for the given session has been lost. Description This operation performs an IEEE 488.1-style clear of the device. For VXI INSTR sessions, VISA must use the Word Serial Clear command. For GPIB INSTR sessions, VISA must use the Selected Device Clear command. For Serial INSTR sessions, VISA must flush (discard) the I/O output buffer, send a break, and
Since the operation viReadSTB() for USB INSTR must retain knowledge of service request notifications, a vendor MAY implement either a queue of status bytes from previous notifications or a single cached status byte, where each received status byte is bit-ORed into the single cached status byte. 6.1.9 viClear(vi) Purpose Clear a device. Parameters Name Direction Type Description vi IN ViSession Unique logical identifier to a session. Return Values Type ViStatus This is the operational return status. It returns either a completion code or an error code as follows. Completion Code Description VI_SUCCESS Operation completed successfully. Error Codes Description VI_ERROR_INV_SESSION VI_ERROR_INV_OBJECT The given session or object reference is invalid (both are the same value). VI_ERROR_NSUP_OPER The given vi does not support this operation. VI_ERROR_RSRC_LOCKED Specified operation could not be performed because the resource identified by vi has been locked for this kind of access. VI_ERROR_TMO Timeout expired before operation completed. VI_ERROR_RAW_WR_PROT_VIOL Violation of raw write protocol occurred during transfer. VI_ERROR_RAW_RD_PROT_VIOL Violation of raw read protocol occurred during transfer. VI_ERROR_BERR Bus error occurred during transfer. VI_ERROR_NCIC The interface associated with the given vi is not currently the controller in charge. VI_ERROR_NLISTENERS No Listeners condition is detected (both NRFD and NDAC are deasserted). VI_ERROR_INV_SETUP Unable to start operation because setup is invalid (due to attributes being set to an inconsistent state). VI_ERROR_CONN_LOST The I/O connection for the given session has been lost. Description This operation performs an IEEE 488.1-style clear of the device. For VXI INSTR sessions, VISA must use the Word Serial Clear command. For GPIB INSTR sessions, VISA must use the Selected Device Clear command. For Serial INSTR sessions, VISA must flush (discard) the I/O output buffer, send a break, and
vpp43_2017-10-17.docx