Stanford Research Systems SR780, Operating Manual And Programming Reference

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3-20 Status Indicators
SR780 Network Signal Analyzer
ALT
Indicates that the ALTERNATE keypad is in use. The ALTERNATE keypad uses the
alphabetic legends printed below each key. To enter the ALT mode, press the [ALT] key
once. Pressing the keys will now enter alphabetic characters into the active entry field.
The [0]...[9], [.], [-], [<-] and [ALT] have the same function in the ALTERNATE keypad.
In ALTERNATE mode, the knob moves the waterfall marker along the Z axis.
To return to the normal keypad, press the [ALT] key again.
GPIB/RS232
This indicator shows ‘RS232’ if the interface responses are directed to the RS232 serial
port.
This indicator shows ‘GPIB’ and the GPIB address if the interface responses are directed
to the GPIB port.
Use <Output To> in the [System]<Remote> menu to select the appropriate interface.
Comm /Error
‘Comm’ is displayed when the computer interface is idle. ‘RS232’ flashes when there is
activity on the RS232 interface. ‘GPIB’ flashes when there is activity on the GPIB
interface.
‘ERR’ flashes whenever a computer interface error occurs, such as illegal command or
out of range parameter is received.
SRQ
This indicator is on whenever a GPIB Service Request is generated by the SR780. SRQ
stays on until a serial poll is completed.
Local/Remote/LOCK
‘local’ indicates that the unit is under local control (front panel enabled).
‘REM’ indicates that the unit is under remote interface control. The front panel may be
locked out by a computer interface. To return the unit to local control, press the
[Help/Local] key. <Overide Remote> in the [System]<Remote> menu allows front panel
control even in the REMOTE state.
‘LOCK’ indicates that the front panel is locked out and no front panel keypress will
return the unit to the local state. No front panel adjustments may be made. An interface
command (LOCL) is required to exit the LOCK state.