Keithley 2520, User Manual, Page: 176 / 329

Model 2520 User’s Manual Status Structure 11-17
Condition registers
As Figure 11-1 shows, each status register set (except the Standard Event Register set) has
a condition register. A condition register is a real-time, read-only register that constantly
updates to reflect the present operating conditions of the instrument. For example, while
the Model 2520 is in the idle state, bit B10 (Idle) of the Operation Condition Register will
be set. When the instrument is taken out of idle, bit B10 clears.
The commands to read the condition registers are listed in Table 11-5 . For details on read-
ing registers, see “Reading registers,” page 11-6 .
Event registers
As Figure 11-1 shows, each status register set has an event register. When an event occurs,
the appropriate event register bit sets to 1. The bit remains latched to 1 until the register is
reset. Reading an event register clears the bits of that register. *CLS resets all four event
registers.
The commands to read the event registers are listed in Table 11-6 . For details on reading
registers, see “Reading registers,” page 11-6 .
Table 11-5
Condition register commands
Command Description
:STATus:OPERation:CONDition?
:STATus:MEASurement:CONDition?
:STATus:QUEStionable:CONDition? Read Operation Condition Register.
Read Measurement Condition Register.
Read Questionable Condition Register.
Table 11-6
Event register commands
Command Description Default
*ESR?
:STATus:OPERation:[:EVENt]?
:STATus:MEASurement:[:EVENt]?
:STATus:QUEStionable:[:EVENt]? Read Standard Event Status Register.
Read Operation Event Register.
Read Measurement Event Register.
Read Questionable Event Register. Note
Note: Power-up and *CLS resets all bits of all event registers to 0. STATus:PRESet has no effect.