2.3
Introduction
2 – 5
2.3
Introduction
Remote operation of the SIM964 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 analog limiter from a remote computer, either through the
SIM900 Mainframe 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 or
flow control, and local echo disabled (
CONS
OFF
).
Most of the SIM964 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 64-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 SIM964 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 SIM964 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 SIM900
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
communication interface; the basic function of the SIM964 is left
unchanged; to reset the instrument, see
*RST
.
2.4
Commands
This section provides syntax and operational descriptions for reo-
mote commands.
SIM964
Analog Limiter
