Basic Operation
The LSS answers incoming calls, determines the port to which the call should
be sent, and routes the call. If a transfer code is received from a Polling
Controller, the LSS routes the call to the requested device, such as a polled
modem.
If no transfer code is received, the call is routed to the default port (Port 1 is the
factory default), usually connected to a telephone. However, if no default port
is defined at the LSS, calls without transfer codes are disconnected.
The Polling Controller ensures that the transfer code is sent at the appropriate
time in the dial string. As a result, data calls are routed to the correct port at
the LSS every time, without guesswork about dial string progress. In addition,
the Polling Controller will hang-up polling calls at the originating end when a
priority outbound call is initiated at the LSS. This ensures that a caller at the
LSS will get faster processing of the priority call.
A single Polling Controller can be used to call many LSS units.
The Polling Controller also translates the routing code supplied in the modem
dial string to either a factory set (i.e., unpublished and proprietary) transfer
code, or to a transfer code programmed by the system manager. The
unpublished and programmable transfer code provide added security to your
substation devices by hiding the remote modem from unauthorized access.
Polling Controller Reference Manual
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