4683 Series: RS485-to-RS485 Network Repeater

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 thirty-two 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

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.

Performance Specifications

Communication Specifications

Baud Rates: Switch settings on unit for 600, 1200, 2400, 4800, 9600, 19.2K, 38.4K, and 76.8K baud rates. Switch must be in the proper baud rate position for proper operation.
RS-485 Bus Loading: One unit load equivalent.
RS-485 Bus Drive:
Complete RS-485 compliance for up to 32 unit loads (31 unit loads if a repeater is used).
See 4683-TTM Data Sheet for details re: End-of-Line Termination Network.
Duplex: Half duplex only
Data Format: Ten bits typical (1 start bit, 8 data bits, and 1 stop bit). Other formats are supported.

Specifications

Power Line Fuse: 0.5A, 125V, 0.75A, 3AG type
Isolation:
Provides galvanic and opto-coupler isolation between RS-485(A), RS-485(B), AC power, and chassis ground.
Common mode voltages are permitted up to 250V rms or 354V DC (withstands a 1500V AC dielectric strength test for 1 min. without breakdown) on a continuous basis.
Complies with requirements outlined in ANSI C39.5-1974 for voltage ratings specified.
RFI Resistance: Withstands an RFI field strength of 10V per meter at 27 Mhz, 151 Mhz, and 467 Mhz with no digital effect, per SAMA PMC 33.1.
Line Noise Effects:
Field and power line terminals withstand ANSI/IEEE C37.90-1978 Surge Withstanding Capability (SWC) Test with no component failures.
Unit is tested to a standardized test waveform that is representative of surges (high-frequency transient electrical interference), observed in actual installations.
Communications Connections:
Network repeater – both RS-485 connectors use modular terminal blocks with screw clamps.
Wire range 14 to 26 AWG.
Power Wire Connections:
Network repeater terminal block
See label on unit for power to be applied to unit
Shipping Weight: 3.0 pounds (1.4 kg) packed per unit

Environmental

Operating Temperature: -25 to 70° C (-13 to 158° F)
Storage Temperature: -25 to +85° C (-13 to 185° F)
Relative Humidity: 0 to 95% RH (non-condensing), up to 40° C (104° F)
Power:
4683-TTM-1F
115VAC ±10%, 50/60 Hz, 0.05A
4683-TTM-2F
230VAC ±10%, 50/60 Hz, 0.03A
4683-TTM-3F
24VAC ±10%, 50/60 Hz, 0.18A typical
Approvals: UL/cUL listed – energy management equipment

Additional information