4683-TTM-3F | N2 BUS REPEATER; 24 V AC | Johnson Controls

N2 BUS REPEATER; 24 V AC

Description

Models 4683-TTM-1F: 115V AC Power 4683-TTM-2F: 230V AC Power 4683-TTM-3F: 24V AC Power

Acromag’s RS-485 network repeater device allows users to take full advantage of the RS-485 standard’s extended communication distances and multi-dropping capabilities. In addition, these devices offer field selectable End-of-Line Network (EOLN) terminations on both the A and B networks.

Operation is transparent to all devices and no handshaking is required. Up to thirtytwo RS-485 devices can be driven. Network repeaters are ready to mount on any base plate. Or, for a harsh environment, it can be installed in a NEMA enclosure of your choice. No enclosure is necessary for use in a laboratory or office. Installation requires mounting, connecting power and cables, and setting the baud rate.

Approvals

UL/cUL listed: Energy management equipment

Key Features & Benefits

• Designed for use with Johnson Controls N2 or BACnet bus
• No handshaking
• No extra control lines
• I/O signal isolation
• Baud rates of 600, 1200, 2400, 4800, 9600, 19.2K, 38.4K, and 76.8K are switch selectable
• Field-selectable end-of-line network terminations on both A and B sides
• Electrical transient protection is provided. This protects the host computer from destructive noise spikes and other transient signals.
• Status LED’s indicate transmission direction, RS-485 bus fault conditions, and power applied.
• 24/115/230V AC power available
• No separate transformer required with 24V AC units (4683-TTM-3F)

Operation Model

4683-TTM-xF network repeaters isolate and boost RS-485 signals allowing communication signals to travel another 4000 ft. Each repeater permits the addition of another 32 unit load to a network.

The repeater has two RS-485 “sides” known as the A and B sides. The A side typically connects to the network towards the host and the B side connects to the extended network. Functionally, the A and B sides are equivalent.

Repeaters receive AC power through a 3-screw terminal strip. Transient signal protection is provided on both RS-485 sides.

When both RS-485 lines are idle, each side is in receive mode. When a ‘1’ to ‘0’ transition is detected (signifying a start bit) on either side, the opposite side’s transmitter is enabled. The transmitter stays enabled for one character’s time (based on the baud rate switch setting). The received character is then passed through.