Agilent Technologies Signal Analyzer N9030a - Manual (Page 128)

3 Programming the Analyzer
STATus Subsystem
What Are Status Registers
The status system contains multiple registers that are arranged in a hierarchical order. The lower-
level status registers propagate their data to the higher-level registers in the data structures by
means of summary bits. The status byte register is at the top of the hierarchy and contains
general status information for the instrument’s events and conditions. All other individual
registers are used to determine the specific events or conditions. For a diagram of the registers
and their interconnections, see above.
The operation and questionable status registers are sets of registers that monitor the overall
instrument condition. They are accessed with the STATus:OPERation and STATus:QUEStionable
commands in the STATus command subsystem. Each register set is made up of five registers:
•
Condition Register—It reports the real-time state of the signals monitored by this register set.
There is no latching or buffering for a condition register.
•
Positive Transition Register—This filter register controls which signals will set a bit in the event
register when the signal makes a low to high transition (when the condition bit changes from 0
to 1).
•
Negative Transition Register—This filter register controls which signals will set a bit in the event
register when the signal makes a high to low transition (when the condition bit changes from 1
to 0).
•
Event Register—It latches any signal state changes, in the way specified by the filter registers.
Bits in the event register are never cleared by signal state changes. Event registers are cleared
when read. They are also cleared by *CLS and by presetting the instrument.
•
Event Enable Register—It controls which of the bits, being set in the event register, will be
summarized as a single output for the register set. Summary bits are then used by the next
higher register.
The STATus:QUEStionable registers report abnormal operating conditions. The status register
hierarchy is:
1. The summary outputs from the six STATus:QUEStionable:<keyword> detail registers are inputs
to the STATus:QUEStionable register.
2. The summary output from the STATus:QUEStionable register is an input to the Status Byte
Register. See the overall system in Figure at the beginning of this section.
The STATus:OPERation register set has no summarized inputs. The inputs to the
STATus:OPERation:CONDition register indicate the real time state of the instrument. The
STATus:OPERation:EVENt register summary output is an input to the Status Byte Register.
128 Remote Language Compatibility Measurement Application Reference