Overview

The Automation & Electronics SDAM was designed to provide analog input expansion capability for Programmable Logic Controllers (PLCs). With a low power requirement and a wide operating temperature range, the SDAM is ideal for use in remote 120 V_AC, 24 V_DC, or solar powered distributed I/O systems. It can also be used as a stand-alone MODBUS analog input module.

The SDAM is a microprocessor based 8 channel analog input card. The inputs can be used in either voltage or current sensing mode. Jumpers are used to configure each of the inputs. Connections are provided for end devices that provide their own loop power and also to provide the loop power to the end devices.

The analog inputs are digitized using a 12-bit analog to digital converter and put through a digital filter. The onboard option switches can be used to select the digital data filtering applied. The onboard microprocessor then makes these readings available to either host systems or master controllers via a serial data highway.

The data highway is implemented using the built in RS-485 serial port. All of the Smart Card series can be daisy chained together using these serial ports. Each Smart Card responds to MODBUS polls or commands from a master. An onboard address selector switch allows each card to be easily configured for any MODBUS address. This RS-485 data highway can then be used to create a scalable, flexible input / output expansion array.

Features