Program Description The instruments are programmed using Direct I/O objects connected as required by the sequence of SCPI commands. Reading of the HP E1476A status byte is performed using the I/O Advanced I/O Device Event object SPOLL whose action is set to ANY SET and its mask set to #H80. This mask allows reading only the OPR bit of the status byte (bit 7) which gets set by bit 8 (Scan Complete) from the Operation Status Register when the switch module completes the scan list. Following the detection of scan complete, the readings are retrieved with the Multimeter’s FETCh? command and sent in an array format to an HP VEE AlphaNumeric Display object titled

HP E1412A Measurements. The readings are also sent to a Strip Chart Display object which gives a plot of the measurements.

Strip Chart Object In parallel with the HP E1412A Measurements AlphaNumeric Display object is a Strip Chart Display object that displays the readings of the eight channels. The Strip Chart has an Auto Scale button to automatically scale the horizontal and vertical axis to best display the measured data. Upper and lower boundary traces could be added to the strip chart’s display.

Chapter 2

HP E1312A/E1412A Multimeter Application Information 65