Stanford Research Systems SR844 User Manual page 91

LOCAL
Remote interface commands can put the SR844 into either the Remote state or the Local
Lockout state. It is possible to configure the unit over the remote interface so that the
front panel is inoperative in these states. See in Chapter 4, Interface Commands, for
information on how to do this. Note that the factory preset values are such that the front
panel is not disabled by Remote commands.
Attempts to change the settings from the front panel will display the message LOCL
LOUT indicating that local control is locked out by the remote interface.
If the unit is in the Remote state and the front panel is locked-out, the Local key will
return the unit to the Local state and re-enable the front panel. In the Local Lockout state,
even the Local key is locked out. It is not possible to distinguish between the Remote
and Local Lockout states from the front panel indicators, since the REMOTE indicator is
on in both cases. If the Local key does not return the unit to the Local state, the unit is
probably in the Local Lockout state. There are three ways to get out of the Local
Lockout state. One is to turn the power off and back on with the Setup key pressed; this
restores the factory preset values. The other two methods are by remote commands and
are discussed in greater detail in Chapter 4, Interface Commands. LOCL0 takes the unit
out of the Local Lockout state, while OVRM1 enables the front panel regardless of
Remote or Local Lockout state.
REMOTE This indicator shows that the SR844 has been put into either the Remote or Local
Lockout state by receipt of a remote command. Front panel control may not be allowed.
This indicator is on when a GPIB service request is generated by the SR844. This
SRQ
indicator remains on until a serial poll is completed. See Chapter 4, Status Register
Definitions, for more information.
ACTIVE This indicator flashes when there is activity (receive or transmit) on either remote
interface.
ERROR This indicator flashes when there is a remote interface error, such as an illegal command,
or a out-of-range parameter.
35
5
36
6
37
7
38
8
49
I
4A
J
4B
K
4C
L
SR844 RF Lock-In Amplifier
Interface 3-33
58
X
59
Y
5A
Z