Back to top

604 SLCR Super Low Cost RTU

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.

604 SLCR Controller Board604 SLCR Controller Board

The Automation & Electronics 604 SLCR is ideal for many Remote Terminal Unit (RTU) applications.

The 604 SLCR is designed to provide local and remote monitoring and control functions at a reasonable price. It has a built in power supply, serial port, and a compliment of useful inputs and outputs.

Used in conjunction with Automation & Electronics SST-9600TM radio or other types of communication equipment, the 604 SLCR can also be easily integrated into a wide variety of SCADA systems.

With the power of the Automation & Electronics LAD language, and the available expansion modules, the 604 SLCR can also be scaled up to perform more complex automation tasks.



  • Two selectable 1-5 VDC or 4-20 mA 12-bit analog inputs
  • Two optically isolated 12 VDC pulse inputs
  • Four optically isolated 12 VDC digital inputs
  • Four 12 VDC 100 mA digital outputs
  • Two form C latching SPDT relay outputs
  • Two expansion connectors for interfacing to added input and output devices
  • Built in RS-232 serial communications port
  • Expansion connector for added serial communications equipment
  • Recognizes MODBUS communications protocol for integrating with SCADA systems.
  • Built in power supply provides power for the 604 SLCR, 12 VDC backup battery charging, 24 VDC loop supply, 12 VDC external accessories, and 8.5-13.5 VDC (adjustable) external accessories.
  • Backup battery operating mode allows the 604 SLCR to continue to run off of an external 12 VDC battery in the event of an AC power failure
  • Eight option switches for programming flexibility
  • Communication address switches allowing addresses from 0 to 255 to be configured.
  • Status indicator LEDs for communications, pulse inputs, discrete inputs, and relay outputs.
  • 120 VAC 0.5 A fused heater output connector.


  • MEB: Provides connections to expansion input/output modules (Max. 2)
  • IMAD: Four 12-bit 1-5 VDC 4-20 mA analog input expansion modules* (Max. 4)
  • RACE: Two 12-bit 4-20 mA analog output expansion modules* (Max. 8)
  • DIF-8: Eight optically isolated 12 VDC digital inputs* (Max. 4)
  • DIF-16: Sixteen optically isolated 12 VDC digital inputs* (Max. 2)
  • FCTB: Sixteen 12 VDC 100 mA digital outputs* (Max. 2)
  • PRO-8 Eight RH2B-U type relay outputs* (Max. 4)
  • SSOT Simple RS-232 serial communication module
  • WRAT 1200 baud bell 202 wire line MODEM.
  • ROAM 1200 baud bell 202 MODEM.
  • SST-9600 9600 baud 928 MHz spread spectrum radio MODEM.
  • PTA 120 VAC power protection module
  • Battery backed RAM.

* Requires a MEB card. Some options cannot coexist with other options. Consult the factory for details on your application.


Size: 12-7/8" x 10-7/8" PC board
Enclosure: 14" x 12" x 6-3/8" NEMA 4X standard typical
Operating temperature: -31 to 140 deg. F (-35 to 60 deg. C)
Relative humidity: 5 to 90% non-condensing
Power requirements
Typical: 1/4 A @ 110 VAC; Less than 2 W @ 12 VDC
CPU / Memory
CPU: 65C02, 8-bit
Memory: 48 kB
Digital inputs: Four on-board, 32 expansion: 10 mA sense current @ 12 VDC, 1500 VDC optical isolation
Digital outputs: Four on-board, 32 expansion: 100 mA 30 VDC open collector type
Relay outputs: Two on-board: SPDT form C latching, 0.6 A @ 125 VAC or 110 VDC, 2 A @ 30 VDC
Pulse inputs: Two on-board: 0 to 3 kHz, 10 mA sense current @ 12 VDC, 1500 VDC optical isolation
Surge Protection: Inputs and outputs designed to meet IEEE STD 472.1974 (SWC) Tests, (ANSI C37.90a-1974)
Serial Port One RJ-45 RS-232 300-19,200 baud port. Support for radio key-on and key-off delays.
Protocols: MODBUS RTU protocol. Custom protocols can also be developed for your specific application
Typical: Automation & Electronics LAD ladder logic programming environment