Fluke PM6685R manual Status Subsystem, Status Reporting Model, Introduction, The Status Structure

Using the Subsystems

Status Subsystem

Introduction

Status reporting is a method to let the controller know what the counter is do- ing. You can ask the counter what status it is in whenever you want to know.

You can select some conditions in the counter that should be reported in the Sta- tus Byte Register. You can also select if some bits in the Status Byte should gen- erate a Service Request (SRQ).

(An SRQ is the instrument’s way to call the controller for help.)

Status Reporting Model

￿The Status Structure

The status reporting model used by CNT-8X is standardized in IEEE 488.2 and SCPI, so you will find similar status reporting in most modern instruments. Figure 6-6 shows an overview of the complete CNT-8X status register struc- ture. It has four registers, two queues, and a status byte:

–The Standard Event Register reports the standardized IEEE 488.2 errors and condi- tions.

–The Operation Status Register reports the status of the CNT-8X measurement cycle (see also ARM-TRIG model, page 6-27).

–The Questionable Data Register reports when the output data from the CNT-8X may not be trusted.

–The Device Register 0 reports when the measuring result has exceeded prepro- grammed limits.

–The Output Queue status reports if there is output data to be fetched.

–The Error Queue status reports if there are error messages available in the error queue.

–The Status Byte contains eight bits. Each bit shows if there is information to be fetched in the above described registers and queues of the status structure.

Using the Registers

Each status register monitors several con- ditions at once. If something happens to any one of the monitored conditions, a summary bit is set true in the Status Byte Register.

Enable registers are available so that you can select what conditions should be re-

6-14 Status Subsystem