Setting And Querying The Status Register - Agilent Technologies ESA-E Series Programmer's Manual

Status Registers
Use Status Registers to Determine the State of Analyzer Events and Conditions
• Monitor a change in the condition of a particular bit, or bits.

Setting and Querying the Status Register

See
value based on its location. This number is sent with the command to
enable a particular bit. To enable more than one bit, send the sum of all
of the bits involved.
For example, to enable bit 0 and bit 6 of the standard event status
register, you would send the command *ESE 65 (1 + 64).
The results of a query are evaluated in a similar way. If the *STB?
command returns a decimal value of 140, (140 = 128 + 8 + 4) then bit 7
is true, bit 3 is true, and bit 2 is true.
Figure 2-3 Status Register Bit Values
15
Bit Number
2-10
Once you have enabled a bit using the event enable register, the
analyzer will monitor that particular bit. If the bit becomes true in
the event register it will stay set until the event register is cleared.
Querying the event register allows you to detect that this condition
occurred even if the condition no longer exists. The event register
can only be cleared by querying it or sending the *CLS command,
which clears all event registers.
Once you have enabled a bit, the analyzer will monitor it for a
change in its condition. The transition registers are preset to
respond to the condition of going from 0 to 1 (positive transitions).
This can be changed so that the selected bit is detected if it goes from
1 to 0 (negative transition), or if either transition occurs. Query the
event register to determine whether or not a change has been made
to how the transition registers respond. The event register can only
be cleared by querying it or sending the *CLS command, which clears
all event registers.
Figure 2-3. Each bit in a register is represented by a numerical
14 13 12 11 10 9 8 6 5 4 3 2 1 0
7
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Chapter 2