Digi 90031300 manual Fault Tolerance, Mixing EPC Concentrators with T1 Modem Bank Units

Daisy Chaining T1 Modem Bank Units and EPC/CON-16 Concentrators

A T1 Modem Bank can be installed in an existing system comprised of EPC/CON-16 concentrators. See Figure 11.

∙ Because existing EPC concentrators are assigned node numbers by the host each time the software is booted, any added T1 Modem Bank units must follow the EPC concentrators in the daisy chain.

∙The last T1 Modem Bank in a daisy chain must have a terminator plug installed on its HOST OUT port. Individual T1 Modem Bank units are not shipped with terminator plugs. Terminator plugs are shipped with EPC/X host adapters only.

∙All EPC concentrators which will be connected to the EPC/X host adapter via synchronous modems must be of the newer type (plastic) if a T1 Modem Bank is to be added to the system.

Figure 11 Mixing EPC Concentrators with T1 Modem Bank Units

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Fault Tolerance

T1 Modem Bank units are assigned physical node numbers (set by the operator during installation—see page 27). The node number is used to route data to and from a specific T1 Modem Bank unit. If a particular T1 Modem Bank is turned off or removed from the daisy chain, the 24 channels on that T1 Modem Bank become unavailable to the system, but the rest of the system remains unaffected. Since the T1 Modem Bank unit’s HOST IN and HOST OUT ports are of the opposite gender, a T1 Modem Bank can be removed from the middle of a daisy chain, and the cables can be connected so that the chain remains unbroken. To remove the last T1 Modem Bank unit, simply plug a terminator plug into the end of the daisy chain cable.

When the hook-up is complete, go to “EPC/X Host Adapter Installation” on page 19 for further instructions.

Hardware Installation 19