Tektronix 070-9180-01 Computer Hardware User Manual


 
Status and Events
4–4
Option 01 VXI Interface Module User Manual
The following example assumes that all bits have been enabled using the Event
Status Enable register (see the next section for information about this register). If
a *ESR? query returns a value of 128, bit 7 (decimal value of 128) is set
indicating that the instrument is in the initial power-on state.
The Event Status Enable register, shown in Table 4–4, controls which events are
summarized in the Event Status bit (bit 5) of the Status Byte register. Use the
*ESE command to set bits in the Event Status Enable register. Use the *ESE?
query to see what bits in the Event Status Enable register are set. The response
from this query is the sum of the decimal values for all bits summarized in the
event status bit of the Status Byte register.
Table 4–4: The Event Status Enable Register
Bit
Decimal
Value
Function
0 1 Set bit 5 of the Status Byte register when bit 1 (the Operation
Complete bit) of the Standard Event Status register is set.
1 2 Not used
2 4 Set bit 5 of the Status Byte register when bit 2 (the Query Error bit )
of the Standard Event Status register is set.
3 8 Not used
4 16 Set bit 5 of the Status Byte register when bit 4 (the Execution Error
bit) of the Standard Event Status register is set.
5 32 Set bit 5 of the Status Byte register when bit 5 (the Command Error
bit) of the Standard Event Status register is set.
6 64 Not used
7 128 Set bit 5 of the Status Byte register when bit 7 (the Power On bit) of
the Standard Event Status register is set.
If, for example, the *ESE? query returns a value of 255, all bits are set,
indicating that all events will set the event status bit (bit 5) of the Status Byte
register.
The Option 01 stores query responses in the Output queue.
The Option 01 error and event messages are stored in the System Error and
Event queue. Use the SYSTem:ERRor? query to get the event number and a text
description of the event. Reading an event removes it from the queue. The Event
queue stores detailed information for up to 10 events; the events are stored in
first-in first-out order.
Event Status Enable
Register
The Output Queue
The System Error and
Event Queue