Modules
R&S
®
OSP
53
User Manual 1178.7100.02 ─ 05
For connecting modules, see
Chapter 2.1.10, "Connecting RF Cables"
Chapter 2.1.11, "Connecting Control Cables"
There are modules with electromechanical relays and with solid-state relays (SSRs) of
the types
and
. Also, some modules feature input and output chan-
nels, multiplexers or attenuators. For details of the modules, refer to the subchapters
linked from the table above. See also the data sheet and the product brochure of the
R&S
OSP.
For system modules R&S
OSP-B15x(x) and R&S
OSP-BSxx(x) (not included in this
manual), refer to the individual user manuals of these modules and to the data sheets
of the test systems.
For the dimensions and installation of modules in a base unit, see
Chapter 2.4.1, "Module Integration Overview"
For information on the base units, see
Chapter 2.2, "Instrument Tour"
FS (open)*
If there is a (partial or full) system blackout, a monostable (failsafe, non-latching) elec-
tromechanical
switch opens the connection between C (common port) and NO
(normally open port). It goes to its default state of connecting C with NC (normally
closed port). Similarly, a monostable (failsafe, non-latching) electromechanical
switch goes to its default connection pattern, typically connecting ports 1+2 and 3+4.
But a monostable (failsafe, non-latching) electromechanical
switch connects C to
no terminal at all. This behavior is called "
failsafe (open)
" (or "
FS (open)
" or "
FS-o
" for
short). Solid-state relays (SSRs) have no defined state at power loss, see
Monostable and bistable relays
Electromechanical relays
can be a monostable or a bistable type:
●
A
monostable
electromechanical relay has two or more switching states, of which
only
one
is stable. The relay remains in this stable state (default state), unless it is
activated, typically by a control voltage. When the control voltage or even the sup-
ply voltage is cut, the relay automatically returns to its default state.
Monostable electromechanical RF relays are called "
failsafe
", because at power
loss the switches automatically return to their disabled (safe) state:
–
An
relay opens the connection from C (common) to the NO (normally
open) port and closes the connection from C to NC (normally closed)
–
An
relay opens the connection from C to all ports, see also
–
relay switches all ports to their default connection pattern
●
A
bistable
) has two switching states, of
which
both
are stable, even when there is no power.
The same holds true for
multistable
electromechanical
relays: one stable
state is with all ports open (reset), the other states are with C connected to one of
the ports.
Switching a bistable or multistable relay from one state to the other or back always
requires an input of energy.