SX8 User Manual
G-‐UM-‐00004 Rev 006
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Implemented Status Structures
There are three distinct status data structures implemented in
the SX8 switch:
•
IEEE 488.2 defined standard registers (standard status
structure)
•
SCPI defined operation registers (operation status structure)
•
SCPI defined questionable registers (questionable status
structure)
The 488.2 standard status structure consists of four registers:
•
status byte register
•
service request enable register
•
standard event status register
•
standard event status enable register
The operation and questionable status structures are identical
except for the use of their individual bits. These status
structures are each composed of five registers:
•
condition register
•
positive transition register (PTRansition)
•
negative transition register (NTRansition)
•
event register
•
event enable register
The bits in the operation status structure reflect a specific condition
within the switch. The SX8 switch only uses bit 1 of the condition
register. Bit 1, the “Settle” bit, is set when the SX8 switch is in the
process of switching channels.
The bits in the questionable registers give an indication of the quality of
the output of the SX8 switch. None of the bits in the questionable
register are currently used by the switch.
All three status structures are connected by the status byte register.
Refer to IEEE488.2 and SCPI1999 documents for the details.
Note that the standard event status register and the event register are
both “sticky” (i.e. once their bits are set to 1 they remain set until they
are cleared by appropriate commands). The status byte register and the
condition register are both dynamic and get updated when the state of
the instrument or the underlying status structures change.
