Campbell Scientific SDS122 Two-Way Serial Data Switch - Manual (Page 5)

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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 CR10/10X 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
Length (over mounting lugs):
195mm
Width (over connectors):
75mm
Height:
22mm
Mounting Holes:
4.8mm dia. (0.1875in) at 177.8mm (7in)
spacing(suitable for mounting onto an
ENC 12/14 enclosure chassis plate)
Weight:
180g
FIGURE 1. General View of SDS-122