SDS122Two-Way Serial Data Switch

The SDS122 is a configurable, two-way serial data switch that allows two modem devices to be connected to a data logger at the same time. The SDS122 connects the data logger to whichever modem initiates communications allowing both remote and local interrogation of the data logger to be carried out. The SDS122 supports both DTE and DCE devices without the need for a null modem cable, and can operate either in manual or automatic mode.

The SDS122 has one CS I/O port and one RS-232 port. The SDS122 answers the first incoming call; the other port receives a busy signal. Common combinations include a COM220 telephone modem and a RAD short haul modem or an SC32B Interface and a RAD short haul modem.

A typical application is to have a telephone modem connected to port B while a personal computer is connected to port A. This configuration allows either device to "talk to" the data logger without the need to connect and disconnect cables at the data logger. Some customers have also found this functionality useful when they wish to provide an easily accessible "walk-up" port for their computer while "burying" the telephone connection in the depths of an instrumentation enclosure.

Current Consumption in Various Modes/Communication Activity: