Introduction - Campbell SDM-SI01A Product Manual

1. Introduction

The SDM-SIO1A and SDM-SIO4A Serial Input/Output Modules are designed to allow expansion
of the number of serial ports available on a data logger for communicating with intelligent
sensors or driving external displays.
The SDM-SIO1A is a functional replacement for the SDM-SIO1 interface, being slightly smaller
and having different labelling for some terminals (see Matching SDM-SIO1A connections to an
SDM-SIO1 [p. 39] for more details of the differences).
Figure 1-1. SDM-SIO1A Serial Input/Output Module
The SDM-SIO4A module is functionally the same as four SDM-SIO1As fitted inside in a compact
case providing four serial ports. The SDM-SIO4A is used in the same way as the SDM-SIO1A and
uses the same CRBasic code in the data logger. Although it has a similar function to the older
SDM-SIO4 module, it is much easier to use, smaller, less expensive, has more flexible outputs,
and uses different instructions in the data logger.
SDM-SIO1A and SDM-SIO4A Serial Input/Output Modules 1