Sigtronics MRIM-2 Bluetooth Cellular Interface - Manual

Sigtronics Intercom and MRIM-2 System with a Bluetooth Cell Phone
Specialists in “SOUND” Management
178 East Arrow Highway, San Dimas, CA 91773 ( 909 ) 305-9399
Made in the U.S.A.
INTRODUCTION
With the simple addition of a Bluetooth car-kit appropriate
for your cell phone, you will have the ability at any time
to sync a hands-free Bluetooth cellular phone to your
Sigtronics intercom / MRIM-2 system.
Four wires are all that is necessary to connect a car-kit to
our MRIM-2 unit. Then just add the power and ground con-
nections to the Bluetooth car-kit and the system is ready
to be synced to your cell phone.
You will have all the benefits of our headset / intercom
system (hearing protection, mobile radio interface, vox
intercom) with the convenience of adding a Bluetooth
cellular phone whenever required.
SYSTEM DESCRIPTION
This system consists of a Sigtronics Emergency Intercom
(either Ultrasound or EAI) with headsets and PTT switches,
a cellular phone with Hands-Free-Mode interfaced through
a user furnished Bluetooth car-kit to our MRIM-2, and as
many 3PDT switch boxes as there are stations that need to
use the phone. The two modes available on these switch
boxes are ICS (intercom and radio) and PHONE.
OPERATION
With all switch boxes in the ICS mode, everyone will hear
and be able to participate in the intercom conversations,
talk and listen on the radio, and hear the phone ring.
When the phone ringer is heard, the person sitting at the
phone controls sets the phone in hands free mode and
switches his switch box to the PHONE mode. He can hear
and talk on the phone, but everyone else on the intercom
cannot hear them, and he cannot hear the intercom.
If the system is installed for more than one person with cell
phone access and the call is for someone else in the vehicle,
he switches back to the ICS mode to tell the other person
to switch over to PHONE mode. When the other person is
through with the call, he will go back to ICS mode and tell
the one at the phone controls to terminate the call.
If two people select the PHONE mode at once, they will
both hear the phone but may not both be able to talk. Only
one at a time should be switched to the PHONE mode.
If a person who is in the PHONE mode pushes his PTT
switch (if he has one), the radio will go into transmit but
no voice will be transmitted, and the intercom will be
muted. While in the PHONE mode, the PTT switch should
not be pushed.
To place an outgoing call, the person at the phone con-
trols would set his switch box to PHONE mode, activate
the phone, dial, and establish contact. He then will switch
over to ICS mode to announce to the other person that the
call is set up and waiting.
WIRING
Each intercom headset station that is to use the phone will
have a switch with three sets of contacts (3PDT) wired as
follows:
HEADPHONE & MIC CONTACTS - The mic and headphone
of the headset shall be connected to the Wiper of first two
sets of contacts (A & B) such that in the ICS position, their
headphone and mic are connected to their normal inter-
com connections. In the PHONE position, the headphone
and mic will be connected to the MRIM-2. Note that, if more
than one headset is switched to the PHONE position, their
headphones will all be in parallel (which is not a problem),
but the mics will also all be in parallel. Electret mics may
not reliably work if paralleled.
RINGING CONTACT - The third contact (C) is wired so that
the MRIM-2 Cell phone receive audio (Blue Wire) runs
through a 100 ohm resistor to the common Intercom Head-
phone buss (also a Blue wire). This way when the switch
is set to ICS, everyone on the intercom will hear the Cell
phone ring during an incoming call. If there will be more
than one headset position wired for phone use, the third
contact is wired in a loop fashion through all switches so
that when any of the switches are set to PHONE this loop
is broken and Cell phone conversation becomes private to
the selected position.
The Green and Red wires of the MRIM-2 must be connected
directly to the Green and Red wires of the intercom to
avoid alternator whine or similar interference. The Black
and PTT wires of the intercom will not be connected to the
switch(es). The Gray wire of the MRIM-2 ties to the Black
wire of the Intercom.