Modules
R&S
®
OSP
97
User Manual 1178.7100.02 ─ 05
The relay shows the following behavior:
–
When the relay is
activated
(control voltage = logical 1, typically when the
inter-
lock loop is closed
), the relay connects C to NO, while disconnecting NC.
–
When the relay is
not activated
(control voltage = logical 0, typically when the
interlock loop is open
) and after reset, the relay automatically falls back to its
default state: It has an RF connection from C to NC, while NO is not connected
to C.
You can use this relay position to disconnect the signal generator from the power
amplifier. Hence, K14 can implement an additional safety feature, if the D-Sub out-
put cannot shut down the amplifier. In this case, you can use the SPDT switch for
directly interrupting the RF signal, typically between the signal generator and the
power amplifier.
However, without power supplied to the relay, it has no defined switching state.
Therefore, SSRs are not inherently failsafe, see
●
INTLK LED
The status LED that is labeled [INTLK] can display the current state of the interlock
loop:
–
If the LED is off, it indicates that the interlock is closed.
–
If the LED shows red light, there is no connection between the input port's pins
2 ("Interlock Loop") and 6 ("+28
V
). It
indicates that the interlock is open.
The relays and I/O ports are mounted directly into the module's panel and soldered to
the module's printed board, to avoid relay cabling and allow compact module size.
The switch unit provides power supply and control via a single module bus cable to a
module bus connector on the module's printed board. The module's on-board memory
stores its configuration data.
Figure 3-63: Pinout and block diagram of RF switch module R&S
OSP-B114
Left
= Pins of the input and output ports
Center = Relay ports
Right = Block diagram of SPDT and DPDT relays and circuitry
R&S
OSP-B114 EMS Test Control Module
