Agilent Technologies 8935 Series Manual do Utilizador descarregar pdf (Página 168)

168 Chapter 6

O:\Manuals\E6380A_Progguid\Book\Advoper.fm

Advanced Operations

HP-IB Service Requests

Setting Up and Enabling SRQ Interrupts

Test Set status information is maintained in eight register groups.

Information in each register group is summarized into a Summary

Message. All of the Summary Messages are, in turn, summarized into

the Status Byte Register, either directly to specific bit positions in the

Status Byte Register as shown in Table 6-10, or indirectly through

another register group (refer to “Status Reporting Structure Overview”

on page 121 for a detailed discussion of the register groups and status

reporting).

Bits in the Status Byte Register can be used to generate a Service

Request (SRQ) message by enabling the associated bit in the Service

Request Enable Register. When an enabled service request condition

exists, the Test Set sends the Service Request message (SRQ) on the

HP-IB bus and reports that it has requested service by setting the

Request Service (RQS) bit in the Status Byte register to the TRUE,

logic 1, state. When read by a serial poll, the RQS bit is cleared (set to

logic 0) so that the RQS message will be FALSE if the Test Set is polled

again before a new reason for requesting service has occurred.

Table 6-10 Status Byte Register Bit Assignments

Bit

Position

Binary

Weighting

Assignments

7 128 Operation Status Register Group Summary Message

6 64 Request Service (RQS) message when read by serial poll, or, Master

Summary Status (MSS) message when read by STB? command

5 32 Standard Event Status Bit (ESB) Summary Message

4 16 Output Queue Message Available (MAV) Summary Message

3 8 Questionable Data/Signal Register Group Summary Message

24 Unused in Test Set

1 2 Hardware #2 Status Register Group Summary Message

0 1 Hardware #1 Status Register Group Summary Message

1 2 ... 163 164 165 166 167 168 169 170 171 172 173 ... 328 329

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Agilent Technologies 8935 Series Manual do Utilizador Página 168