1257 User Manual
EADS North America Defense
Advanced SCPI Operations 7-1
Test and Services, Inc.
©
2001
Chapter 7
ADVANCED SCPI OPERATIONS
Introduction
The 1257 Switching System offers a number of advanced functions
to give you precise control over the instrument. These functions
can be accessed only via the IEEE-488 (GPIB) and RS-232
interfaces.
Using ROUTE:
CONFIGURE to
Control Switching
Sequence
The ROUTE:CONFIGURE command controls the sequence in
which relays are opened and closed when more than one relay has
been commanded to change. The command has the form:
ROUTE:CONFIGURE (@<module address>),<seqmode>
The <seqmode> parameter may be one of three modes:
•
IMM (Immediate):
Causes channels (relays) to be opened and
closed as quickly as possible. The sequence of opening and
closing is indeterminate. In this mode, care must be taken to
avoid damaging equipment while the relays are in transition,
i.e. by short circuiting power supplies, connecting high-power
outputs together, or applying excessive power to low-
impedance inputs.
•
BBM (Break Before Make):
Causes existing channel closures
to be opened before new channel closures are made. BBM is
the default mode on power-up, or after the 1255A has been
reset.
•
MBB (Make Before Break):
Causes new channel closures to
be made before existing channel closures are opened.
For example, the following command:
ROUTE:CONFIGURE (@1),MBB
causes the drawer installed in the 1257 to operate in Make-Before-
Break mode.
