SYSTem:LOCK:OWNer?
Returns the I/O interface that currently has a lock.
Parameter Typical Return
(none) "LAN169.254.149.35"
See Interface Locking Example
l When a lock is active, Bit 10 in the Standard Operation Register will be set (STATus:OPERation:CONDition?). When
the lock is released on all I/O interfaces, this bit will be cleared.
l Returns "USB", "VXI11", "GPIB", or "LAN <IP Address>" indicating the I/O interface that currently has a lock. If
no interface has a lock, "NONE" is returned.
SYSTem:LOCK:RELease
Decrements the lock count by 1 and may release the I/O interface from which the command is executed.
Parameter Typical Return
(none) (none)
See Interface Locking Example
l When a lock is active, Bit 10 in the Standard Operation Register will be set (STATus:OPERation:CONDition?). When
the lock is released on all I/O interfaces, this bit will be cleared.
SYSTem:LOCK:REQuest?
Requests a lock of the current I/O interface. This allows you to lock the instrument's configuration or cooperatively
share the instrument with other computers.
Parameter Typical Return
(none) +0 (denied) or +1 (granted)
See Interface Locking Example
l Lock requests can be nested; each request increases lock count by 1. For every request, you will need a release
(SYSTem:LOCK:RELease) from the same I/O interface.
l Locks are handled at the I/O interface level (USB, LAN, etc.) and you are responsible for all coordination between
threads and/or programs on that interface.
l When a request is granted, only I/O sessions from the present interface can change the instrument state. You can
only query the instrument state from other I/O interfaces.
l LAN sessions locks are automatically released when a LAN disconnect is detected.
l Granting a lock sets Bit 10 in the Standard Operation Register (STATus:OPERation:CONDition?). In addition, the
entire instrument front panel, including the Local key, is locked out while a lock is in place ("Front panel locked." is
displayed).
250 Agilent Truevolt Series DMM Operating and Service Guide