Keithley 6487 Reference Manual

Model 6487 Reference Manual Status Structure 10-15
Figure 10-7
Questionable event status
Condition registers
As Figure 10-1 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 6487 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 10-4. For details on read-
ing registers, see “Reading registers,” page 10-6.
Table 10-4
Common and SCPI commands — condition registers
Command Description
STATus
:OPERation:CONDition?
:MEASurement:CONDition?
:QUEStionable:CONDition?
STATus subsystem:
Read operation condition register.
Read measurement condition register.
Read questionable condition register.
OR
Warn = Command Warning
Cal = Calibration Summary
& = Logical AND
OR = Logical OR
&
&
16384
(2
14
)
Decimal
Weights
[:EVENt]?
128
(2
7
)
(B6-B0)
Cal
(B7)
Warn
(B14) (B13-B8)
(B15)
:CONDition?
Cal
(B7)
Warn
(B14) (B13-B8)
(B15)
Questionable
Condition Register
:ENABle <NRf>
:ENABle?
(B6-B0)
Questionable
Event Register
Warn
(B14) (B13-B8)
(B15)
(B6-B0)
Questionable Event
Enable Register
Cal
(B7)
To QSB bit
of Status Byte
Register

Keithley 6487 Specifications

General

Type	Picoammeter/Voltage Source
Current Measurement Range	20 fA to 20 mA
Interfaces	GPIB, RS-232
Voltage Burden	< 200 µV
Input Impedance	>10^14 Ω
Power	100 V / 120 V / 220 V / 240 V
Basic Current Measurement Accuracy	0.4%