National Instruments GPIB-SCSI-A, Руководство пользователя

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Chapter 6 Programming in G Mode
© National Instruments Corp. 6-5 GPIB-SCSI-A User Manual
Status and Error Information
The function descriptions in Chapter 7, G Mode Functions, explain that the
GPIB-SCSI-A records specific status and error information. This means
that it stores that information in its memory so that when you request it it is
available.
The function descriptions also explain that the GPIB-SCSI-A returns to you
certain information. This means that the GPIB-SCSI-A sends information
to you over the GPIB when requested. You then interpret this status in your
application. This information is returned either separately in response to the
issuing of the
stat
command or continuously if specified by the
C
flag in
the
stat
command. In the event of an error, the GPIB-SCSI-A may or
may not complete the command to its fullest extent, depending on the error.
For more information about G mode error indications, refer to the
description of
stat
in Chapter 7, G Mode Functions, as well as Appendix
B, Status and Message Information.
Communicating with the GPIB-SCSI-A and SCSI
Peripherals
The GPIB-SCSI-A uses two channels for data processing. These channels
are referred to as the Command and Status Channel and the Data Channel.
The GPIB-SCSI-A differentiates between the data depending on which
channel is addressed.
There are two different ways to address the channels. The types of
addressing are user selectable between Major/Minor GPIB addressing and
secondary GPIB addressing by setting Switch 5 of SW2. For a more
detailed description of the two types of addressing, refer to the Switch 5
section in Chapter 3, Technical Information.