Multimeter Status System Examples - HP E1312A User Manual

Multimeter Status
There are two program examples that demonstrate how the HP E1312A and
HP E1412A Multimeter status system works. In both programs the status
System Examples
byte is repeatedly read to identify when actions by the Multimeter set the
appropriate bit in the status byte. The computer can identify when readings
are available by monitoring the status byte and can retrieve readings when
they are available.
Figure 2-5 illustrates the HP E1312A and HP E1412A status system. A
Questionable Data Register, an Output Buffer and a Standard Event Register
each have a respective status bit in the Status Byte Register. The Output
Buffer sets the MAV bit when there is data available such as measurement
readings or a response to a SCPI query command. The Questionable Data
Register and Standard Event Register require you to "unmask" the bits you
want to be OR'd into a summary bit which sets the respective bit in the Status
Byte. You must also "unmask" the status bits you want OR'd into a summary
bit to set the Service Request bit (SRQ) if you want to generate an interrupt.
The B-size HP E1312A requires you unmask any bit with the *SRE
command that you want to read with a SPOLL (the HP E1412A does not
require this unmasking). The example programs illustrate this requirement.
Figure 2-5. HP E1312A/E1412A Multimeter Status System
60 HP E1312A/E1412A Multimeter Application Information Chapter 2