Keithley 6485 User Manual

Model 6485 Picoammeter Instruction Manual Status Structure 10-7
Status byte and service request (SRQ)
Service request is controlled by two 8-bit registers; the status byte register and the service
request enable register. Figure 10-3 shows the structure of these registers.
Figure 10-3
Status byte and service request
Table 10-2
SCPI command — data formats for reading status registers
Command Description Default
:FORMat
:SREGister <name>
FORMat subsystem
Select data format for reading status registers:
<name>=ASCii Decimal format
HEXadecimal Hexadecimal format
OCTal Octal format
BINary Binary format
ASCii
Status Summary Messages (6)
OSB
(B7)
RQS
(B6)
MSS
ESB
(B5)
MAV
(B4)
QSB
(B3)
EAV
(B2)
(B1)
(B0)
OR
* SRE
* SRE?
Status Byte
Register
Service Request
Enable Register
OSB = Operation Summary Bit
MSS = Master Summary Status
RQS = Request for Service
ESB = Event Summary Bit
MAV = Message Available
QSB = Questionable Summary Bit
EAV = Error Available
MSB = Measurement Summary Bit
& = Logical AND
OR = Logical OR
OSB
(B7) (B6)
ESB
(B5)
MAV
(B4)
QSB
(B3)
EAV
(B2)
(B1)
(B0)
&
&
&
&
&
MSB
MSB
&
128
(2
7
)
32
(2
5
)
16
(2
4
)
8
(2
3
)
4
(2
2
)
1
(2
0
)
Decimal
Weights
* STB?
Serial Poll
Service
Request
Generation

Keithley 6485 Specifications

General

Model	Keithley 6485
Category	Picoammeter
Input Impedance	>10^14 Ohms
Voltage Burden	<200µV
Accuracy	0.4% of reading
Voltage Source Range	Not Applicable
Voltage Source Resolution	Not Applicable
Voltage Source Accuracy	Not Applicable
Interface	IEEE-488
Power Requirements	100V to 240V AC, 50/60Hz
Dimensions	89 mm high x 214 mm wide x 369 mm deep (3.5 in x 8.4 in x 14.5 in)