Stanford Research Systems SR844, Руководство пользователя

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Interface 4-29
SR844 RF Lock-In Amplifier
Interface Commands
*RST
The *
RST
command resets the SR844 to its default configuration. The
communications setup is not changed. All other modes and settings are set to their
default conditions and values. This command takes some time to complete. This
command resets any data scan in progress. Data stored in the buffers will be lost.
PRST
The
PRST
command does a power-on reset. In addition to resetting the
configuration, the DSP and programmable logic are re-loaded, and the
communication ports are reset. This command takes about 5 seconds to complete;
no new commands will be recognized in the meantime.
The next command (after IFC ready becomes set again) should be
OUTX i
.
*IDN?
The *
IDN?
query returns the SR844’s device identification string. This string is in
the format
Stanford_Research_Systems,SR844,s/n00111,ver1.00
In this example, the serial number is 00111 and the firmware version is 1.00
LOCL (?) {i}
The
LOCL
command sets or queries the local/remote state. The SR844 is put into
the Local (
i=0
), Remote (
i=1
) or Local Lockout (
i=2
) state. These states
duplicate the GPIB local/remote states. In the Local state both remote command
execution and keyboard input are allowed. In the Remote state remote command
execution is allowed, but the keyboard and knob are locked out, except for the
Local
key which returns the SR844 to the Local state. In the Local Lockout state
the entire front panel is locked out, including the Local key.
The REMOTE indicator is on in the Remote and Local Lockout states.
The Override Remote mode (below) must be set to Off in order for the front panel
to be locked out. If Override Remote is On, then the front panel is active even in
the Remote and Local Lockout states.
The
LOCL?
query returns 1 or 2 for the Remote and Local Lockout states. The
unit cannot return 0 (Local state) since receipt of the
LOCL?
query will put the
unit into the Remote state.
OVRM (?) {i}
The
OVRM
command sets or queries the Override Remote mode. The parameter
i
selects Off (
0
) or On (
1
).
The default mode is Override Remote On. In this mode the front panel is always
active, regardless of the Remote or Local Lockout state. (The
REMOTE
indicator
still indicates Remote or Local Lockout.)
To lock-out the front panel, use the
OVRM0
command. In the Remote state, only
the
Local
key is active. Pressing the
Local
key will reactivate the front panel. If
the unit is in Local Lockout, the entire front panel will be disabled (including the
Local
key). To reactivate the front panel, issue
OVRM1
or
LOCL0
.