Automated Logic RT683 DDC Control Module for Rooftop Units. . . . . . The RT683 is a DDC module designed specifically for controlling rooftop air handling units. The module can be mounted directly in or on the rooftop equipment. A single board provides the power circuitry, microprocessor, and non-volatile memory. The R683 module has 6 digital outputs, 8 universal inputs, and 3 analog outputs.

The RT683 module is a member of the I/O Hardware family of control modules. Each module is capable of standalone operation. All modules communicate with equal authority on a "peer-to-peer" EIA-485 Control Module Network (CMnet). A direct access port is provided for diagnostic operations.

The RT683 module can store a single Graphic Function Block (GFB).

Power: 24 VAC, 50-60 Hz, 20 VA (0.83 A) maximum.

Inputs: One enhanced zone sensor port and 8 universal inputs (thermistor/dry contact, 0-5 VDC, or 4-20 mA).

Digital Outputs: 6 relay outputs (Form A), 3 A max.

Analog Outputs: 3 analog outputs (0-10 VDC), 20 mA source capability.

Communication: EIA-485 port for CMnet communication. Baud rate: 9600 bps or 38.4k bps (switch selectable). CMnet terminals are optically isolated.

Status Indication: LED indicators for visual status of communication, errors, running, and all outputs.

Memory: 32k byte non-volatile read/write memory.

Protection: Noise immunity provided by metal cover plate, surge protection on network, inputs, and power lines, arc suppression on relays.. Automated Logic. Automated Logic Corporation.