SYSTem:LOCK:REQuest?

34980A

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

See Also

SYSTem:LOCK:OWNer?

SYSTem:LOCK:RELease