SYSTem:LOCK:REQuest?
Syntax
SYSTem:LOCK:REQuest?
Description
This command requests a lock of the current I/O interface. This provides a mechanism by which you can lock the instrument's configuration or cooperatively share the instrument with other computers.
Remarks
Lock requests can be nested and each request will increase the lock count by 1. For every request, you will need to do a release (see SYSTem:LOCK:RELease command).
Instrument locks are handled at the I/O interface level (GPIB, USB, LAN, etc.) and you are responsible for all coordination between threads and/or programs on that interface.
When a request is granted, only I/O sessions from the present interface will be allowed to change the state of the instrument. From the other I/O interfaces, you can query the state of the instrument but no other configuration changes or measurements are allowed.
Locks from LAN sessions are granted by the IP address.
Locks from LAN sessions will be automatically released when a LAN disconnect is detected.
When a lock is granted, Bit 10 in the Standard Operation Register will be set (see STATus:OPERation:CONDition? command). In addition, the entire instrument front panel, including the LOCAL key, will be locked out while a lock is in place ("KEYBOARD LOCKED" is displayed).
Return Format
The command returns "+1" if the lock request is granted or "+0" if denied.
Example
The following command requests a lock of the current I/O interface.
SYST:LOCK:REQ?
Typical Response: +1