Stanford Research Systems SR844, Руководство пользователя

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3-32 Interface
SR844 RF Lock-In Amplifier
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 Configuration Notes
GPIB/
RS232 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.
ADDRESS
Use the knob to select a GPIB address for the SR844.
BAUD Use the knob to select a RS232 baud rate from 300 to 19200 baud.
PARITY Use the knob to select
EVEN
,
ODD
or
NONE
for the RS232 parity.
QUEUE 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 Hex ASCII Hex ASCII
0A
linefeed
39
9
4D
M
2A
*
3B
;
4E
N
2B
+
3F
?
4F
O
2C
,
41
A
50
P
2D
–
42
B
51
Q
2E
.
43
C
52
R
30
0
44
D
53
S
31
1
45
E
54
T
32
2
46
F
55
U
33
3
47
G
56
V
34
4
48
H
57
W