Campbell SDS-122, User Manual

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SDS-122 Serial Data Switch
The SDS-122 is a configurable two-way serial data switch which will allow two modem
devices to be connected to a datalogger simultaneously, so allowing both remote and local
interrogation of the datalogger to be carried out. It can support both DTE and DCE devices
without the need for a null modem cable, and can operate either in manual or automatic
mode.
1. Introduction
The SDS-122 will normally be fitted in a datalogger enclosure. It allows two
modems to be connected to a single datalogger at the same time and can
automatically switch the datalogger to communicate with whichever modem
initiates communications.
The SDS-122 can support both DTE and DCE devices without the need for a null
modem cable, and can emulate an SC932 (9-pin to RS232-DCE) interface. One
port of the SDS-122 can also be configured to emulate an optically isolated
SC32A interface in either DCE or DTE mode. A jumper switch is provided for
use with CR500/510, CR10/10X and CR23X dataloggers to block the
transmission of synchronous data.
The SDS-122 can be set either for fully automatic mode, or manual mode,
controlled by a datalogger control port or any logic signal. When in automatic
mode, the SDS-122 can be configured to either hold the last port rung or to
default to a specific port, when communication finishes on either port.
2. Specifications
2.1 Physical
Figure 1 General View of SDS-122
Length (over mounting lugs): 195mm
Width (over connectors): 75mm
Height: 22mm