Keithley 6487 User Manual

Model 6485 and 6487 User’s Manual Remote Operation and Commands 7-7
The query command requests the presently programmed status. It is identified by the ques-
tion mark (?) at the end of the fundamental form of the command. Most commands have a
quer
y form.
Each program message must be terminated with an
LF (line feed), EOI (end or identify), or
an LF+EOI. Each response is terminated with an LF (line feed) and EOI (end or identify).
Parameter types
The following are some of the common parameter types:
<b> Boolean — Used to enable or disable an instrument operation. 0 or
OFF di
sables the operation and 1 or ON enables the operation.
<name> Name parameter — Select a parameter name from a listed group.
<NRf> Numeric representation format — A number that can be expressed
as an integer (e.g.,
8), a real number (e.g., 23.6), or an exponent
(2.3E6).
<NDN> Non-decimal numeric — A non-decimal value
that can be used to
program status enable registers. A unique header identifies the
format: #B (binary), #H (hexadecimal), and #Q (octal).
<n> Numeric value — Can consist of an NRf number or one of the fol-
lowing name parameters: DEFault, MINimum, or MAXimum.
When
the DEFault parameter is used, the instrument is programmed
to the *RST default value. When the MINimum parameter is used,
the instrument is programmed to the lowest allowable value. When
the MAXimum parameter is used, the instrument is programmed to
the largest allowable value.
Angle brackets < > — Used to denote a parameter type
. Do not include the brackets in the
program message.

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%