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SDIO 48 Channel Discrete Input / 48 Channel Discrete Output Smart Card

This product has been discontinued. This web page is provided so current customers using the product can have a quick reference for specifications. Please contact Automation Electronics for current products that may meet your needs.

48 channel discrete in/ discrete out smart card48 Channel Discrete Input/48 Channel Discrete Output Smart Card (SDIO)

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

The SDIO is a microprocessor based 48-channel digital input and 48-channel digital output board. The inputs from this card can be connected to the DIF8, DIF16 or equivalent input boards. The outputs can be connected to the PRO4, PRO8 or FCTB output boards. The on-board microprocessor monitors the status of the inputs, controls the outputs, and makes them 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 on-board 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.


  • Digital output state backup (24 hour via on-board capacitor)
  • MODBUS RTU protocol
  • On-board address switch (0-255)
  • Four on-board option switches
  • Two RJ45 jacks for RS-485 serial data
  • Selectable RS-485 termination
  • Expansion connector for our P-type piggyback modules


Size: 4-1/2" x 9" PC board
Mounting: Snap track
Operating temperature: -40 to +158 deg. F (-40 to +70 deg. C)
Relative humidity: 5 to 90% non-condensing
Power requirements
Typical: Processor - Less than 100 mA @ 10 to 30 VDC
CPU / Memory
CPU: 68HC11
Memory: 128 kB flash, 32 kB EEPROM, 2 kB RAM
Inputs / Outputs
Inputs: Three 16-pin connectors; CMOS or LS TTL compatible
Outputs: Three 16-pin connectors; open collector type; 100 mA 30 VDC maximum; suppression diodes may be required
RS-485: 9,600 baud; two RJ45 connectors
Protocols: MODBUS RTU protocol