User manual

8
8. Trunk Master B TrunkEdit connector. Connects to COM port 2 of the TM-2000/MTM-2000 assigned to be Trunk
Master B.
9. Trunk Master B parallel port. Connects to parallel printer port of the TM-2000/MTM-2000 assigned to be Trunk
Master B. Provides control from the SWP-2000 to the TM-2000/MTM-2000 and LED status monitoring of the TM-
2000/MTM-2000 and LED status monitoring of the TM-2000/MTM-2000 on the SWP-2000 front panel.
Understanding Trunking
In a trunking system, the audio lines (not data) of one or more intercom ports are interconnected between two separate
intercom systems. The system administrator in each intercom system then places restrictions on these ports to prohibit them
from being assigned to any keys. This reserves the ports for exclusive use as trunking lines. A special RS-485 data link is also
connected from each intercom system to the Trunk Master for exchange of system control signals. The main difference
between the
TM-2000 and the MTM-2000 is the number of intercom systems it can communicate with. The TM-2000 supports up to 32
ports (see the NOTE below), whereas the MTM-2000 can support up to 16 ports. Once the interconnections are completed, the
trunk master is programmed, using TrunkEdit, to recognize the individual intercom systems.
After the trunk master has been programmed, system administrators or keypanel users in each intercom system may request
lists of people, party lines, etc. from other intercom systems for the purpose of key assignment just as they would in their own
intercom system.
After keys are assigned, keypanel operators can activate, talk or listen to them just like in their own intercom system. There is
no apparent difference to keypanel operators, but what actually occurs in the system electronics is slightly different. When a
keypanel operator activates a key to talk to a destination located in another intercom system, the intercom system’s master
controller does not act itself to close any crosspoint, but rather, it sends this information to the trunk master via the data
connection. The Trunk Master then checks for an available trunk line. If one is available, it notifies the master controllers in
the affected intercom systems to establish the communication path using the trunk line that it specifies. If no trunk lines are
available, the trunking system will notify the master controller in the caller’s intercom system, which will then send a “busy”
signal to the calling keypanel.
If more than two intercom systems are interconnected, additional trunk lines must be reserved and interconnected between the
systems. However, it is not always necessary that two intercom systems be directly interconnected as long as there is a path not
more than one system away to connect the two systems. The trunking system can be programmed to permit “cascaded”
trunking in which a pathway is established through an intermediate intercom system to connect two endpoints.
NOTE: The system and its software only support a single level of cascade. For example, System A wants to talk to
System C, but it does not have a direct connection to System A and to System C. System A can talk to System C
by going through (cascading) System B. However, it would be impossible for System A to talk to System D if it
had to go through both System B and System C to do so, because that would require two levels of cascade.