Tektronix 070-9197-00 User Manual

Page of 72
PS2520G and PS2521G Programmer Manual
41
Status and Events
The PS2520G and PS2521G Programmable Power Supplies provide
a status and event reporting system for the GPIB interface. Various
registers and queues make up this system. This section explains how
these registers and queues work to inform you of significant events.
System Structure
Figure 7 on page 43 is a simplified diagram of the status and event
reporting system. In reality, each component of the diagram
represents a set of registers and queues that read, report, or enable
the occurrence of certain events within the system.
Status reporting begins when a specific event in the programmable
power supply sets a bit in a status register. Reading the status
registers tells you what types of events have occurred.
Each bit in the status register corresponds to a bit in an enable
register
; the enable bit must be high for the event to be reported to
the Status Byte Register.
The Output Queue stores and reports query responses. The
Error/Event Queue stores and reports error messages.
A Service Request (SRQ) is the last event to occur. The SRQ
requests an interrupt on the GPIB to report events to the system
controller.
The following sections explain the registers and queues in greater
detail.