2 – 4
Remote Operation
2.3
Introduction
Remote operation of the SIM910 is through a simple command lan-
guage documented in this chapter. Both set and query forms of most
commands are supported, allowing the user complete control of the
amplifier from a remote computer, either through the SIM900 Main-
frame or directly via RS-232 (see Section 1.4.2.1).
See Table 1.1 for specification of the DB–15 SIM interface connector.
2.3.1
Power-on configuration
The settings for the remote interface are 9600 baud with no parity,
hardware flow control, and local echo disabled (
CONS
OFF
).
Most of the SIM910 instrument settings are stored in non-volatile
memory, and at power-on the instrument returns to the state it was
last in when power was removed. Exceptions are noted in the com-
mand descriptions.
Reset values of parameters are shown in
boldface
.
2.3.2
Buffers
Incoming data from the host interface is stored in a 32-byte input
bu
ff
er. Characters accumulate in the input bu
ff
er until a command
terminator (either
h
CR
i
or
h
LF
i
) is received, at which point the mes-
sage is parsed and executed. Query responses from the SIM910 are
bu
ff
ered in a 64-byte output queue.
If the input bu
ff
er overflows, then all data in
both
the input bu
ff
er
and the output queue are discarded, and an error is recorded in the
CESR
and
ESR
status registers.
2.3.3
Device Clear
The SIM910 host interface can be asynchronously reset to its power-
on configuration by sending an RS-232-style
h
break
i
signal. From the
SIM900 Mainframe, this is accomplished with the
SRST
command;
if directly interfacing via RS-232, then use a serial break signal. After
receiving the Device Clear, the interface is reset to 9600 baud and
CONS
mode is turned
OFF
. Note that this
only
resets the communi-
cation interface; the basic function of the SIM910 is left unchanged;
to reset the instrument, see
*RST
.
SIM910
JFET Preamp
