User`s manual

Synchronizing the Multimeter with a Computer
This is an example of how an HP 9000 Series 200/300 computer can
monitor the multimeter to determine when data is available. This allows the
computer to perform other functions while the multimeter is making
measurements. When the readings are available, the computer stops its
current function and enters the data.
10 !Dimension a computer array to store the readings.
20 DIM Rdgs(1:15)
30 !
Clear and reset the multimeter. Unmask the Message Available (MAV)
40 !bit (4) in the Status Byte Register.
50 OUTPUT 70903;"*CLS"
60 OUTPUT 70903;"*RST"
70 OUTPUT 70903;"*SRE 16"
80 !
Configure the multimeter for DC voltage measurements. Make 5 scans
90 !through the channel list with each scan 5 seconds apart. Store the
100 !readings in mainframe memory.
110 OUTPUT 70903;"CONF:VOLT:DC (@104:106)"
120 OUTPUT 70903;" TRIG:COUN 5"
130 OUTPUT 70903;" TRIG:DEL 5"
140 OUTPUT 70903;"INIT"
150 OUTPUT 70903;"FETC?"
160 !
Monitor the message available bit. Have the computer perform another
170 !function (e.g. display a message) until the bit indicating a reading is
180 !available is set. Enter and display the readings.
190 WHILE NOT BIT (SPOLL(70903),4)
200 DISP "WAITING FOR DATA"
210 WAIT 1
220 DISP ""
230 WAIT 1
240 END WHILE
250 ENTER 70903;Rdgs(*)
260 FOR
I=1 TO 15 STEP 3
270 PRINT Rdgs(
I),Rdgs(I+1),Rdgs(I+2)
280 NEXT
I
290 END
Comments
• Readings are not fetched from memory until all scans and all
measurements have completed.
• The message available bit (MAV) is set when the first reading
retrieved from memory enters the output buffer.
• Only the data from one command can be in the output buffer or in
mainframe memory. Synchronizing the computer with the
multimeter in this manner ensures the data is entered into the
computer before it is overwritten by data from another command.
68 Using the HP E1326B/E1411B Multimeter Chapter 3