Interface Locking; Address Selection; Remote Interface Operation - Metek Sorensen XEL serie Manual De Operación

The instrument can be remotely controlled via its RS232, USB, LAN or GPIB (optional) interfaces.
Analog remote control is described in the previous section.
USB remote control operates in a similar way to RS232 but via the USB connector. Software
supplied with the instrument sets up the controlling computer to treat the USB connection as a
virtual COM port. Application software on the computer can then access the instrument via that
COM port.
The LAN interface is designed to meet LXI ( Lan eXtensions for Instrumentation) version 1.2; the
instrument is Class C compliant. Remote control using the LAN interface is possible using the
TCP/IP Sockets protocol. The instrument also contains a basic Web server which provides
information on the unit and allows it to be configured from a web browser. Simple command line
control from the browser is also possible.
The instrument is supplied with RS232, USB, and LAN as standard; GPIB is an option. All
interfaces are, by default, live at all times (a LXI requirement) but access to individual interfaces
may be restricted using the configuration options on the web pages.

Interface Locking

All interfaces are live at all times; this removes the need to select the active interface and is also a
LXI requirement. To reduce the risk of the instrument being inadvertently under the control of two
interfaces at once a simple lock and release mechanism is provided in the instruction set. The lock
is automatically released where it is possible to detect disconnection and when the local button is
pressed. Access to the interfaces may also be restricted using the web pages.
Any interface may request to have exclusive control of the instrument by sending an "IFLOCK"
command. The lock may only be released by sending an "IFUNLOCK" command from the interface
instance that currently has the lock and may be queried from any interface by sending an
"IFLOCK?" command. The reply to any of these commands will be "-1" if the lock is owned by
another interface instance, "0" if the interface is free and "1" if the lock is owned by the requesting
interface instance. Sending any command from an interface without control privileges that attempts
to change the instrument status will set bit 4 of the Standard Event Status Register and put 200 into
the Execution Error Register to indicate that there are not sufficient privileges for the required
action.
Note: it is also possible to configure the privileges for a particular interface to either 'read only' or
'no access' from the Web page interface.

Address Selection

The instrument address capability is strictly required only by the GPIB interface. However, use can
be made of the ADDRESS? command over any of the interfaces to easily identify which instrument
is being controlled by a particular COM port (for RS232 or USB) or TCP socket (for LAN). Note that
the LAN interface also has a separate 'Identify' function, accessible from the instrument's web
pages, that flashes the instrument's display until the function is cancelled.
The address is set from the instrument's front panel as follows. Start with the instrument off and,
with the Lock, Meter Average and Current Range keys all held down switch the instrument on. The
display will show
setting (default
Average and Current Range keys respectively in the range 1 to 31 inclusive (not 0), with 'wrap-
round'. The address is confirmed and the process exited by holding down the Lock key; the display
will show SEt
mA display when the new address has been accepted.
The address can also be set from the instrument's web pages.
22
Addr in the Volts display and
Addr 11 ). The address can be decremented and incremented by the Meter
and the new address for approximately 2 seconds, returning to the normal Volts and

Remote Interface Operation

nn in the mA display where nn is the present