Interface - Stanford Research Systems SR844 User Manual

3-32 Interface

Interface
The SR844 can be interfaced to a host computer via RS232 or GPIB. The keys in
this section configure the interface for proper operation with the host. These
parameters must be set before attempting to interface the instrument to the host
computer.
Setup The Setup key cycles through the remote interface configuration parameters. Indicators
above the Setup key indicate which parameter is being shown. The value or setting of
the parameter is displayed on the Reference Display and is adjusted using the knob. See
Chapter 4, Introduction, for more information about setting the correct interface.
Parameter
GPIB/
RS232
ADDRESS
BAUD
PARITY
QUEUE
SR844 RF Lock-In Amplifier
Configuration Notes
The SR844 outputs data to only one interface at a time. Commands may
be received over both interfaces but responses are directed only to the
selected interface. Use the knob to select either GPIB or R232 for the
output interface.
Use the knob to select a GPIB address for the SR844.
Use the knob to select a RS232 baud rate from 300 to 19200 baud.
Use the knob to select EVEN, ODD or NONE for the RS232 parity.
The last 256 characters received by the SR844 may be displayed to help
find programming errors. Setup Queue will display 6 hexadecimal
characters at a time (2 each on the Channel 1, Channel 2 and Reference
displays). Turn the knob CCW to move farther back in the buffer and
CW to move towards the most recently received characters. A period '.'
is displayed to indicate the ends of the buffer. All characters are
changed to upper-case, spaces are removed, and command delimiters are
changed to linefeeds (0A).
The table below shows the hexadecimal equivalents of all of the
characters recognized by the SR844.
Hex ASCII
0A
linefeed
2A
*
2B
+
2C
,
2D
–
2E
.
30
0
31
1
32
2
33
3
34
4
Hex ASCII
39
9
3B
;
3F
?
41
A
42
B
43
C
44
D
45
E
46
F
47
G
48
H
Hex ASCII
4D
M
4E
N
4F
O
50
P
51
Q
52
R
53
S
54
T
55
U
56
V
57
W