HP WaterSkis E1312A, WaterSkis E1412A manual Multimeter Status System Examples

Multimeter Status System Examples

There are two program examples that demonstrate how the HP E1312A and HP E1412A Multimeter status system works. In both programs the status 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