User guide

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SeaLINK+16.VC User Manual

Technical Description

The SeaLINK+16.VC utilizes sixteen USB UARTs. These chips feature

programmable baud rate, data format, 128 byte Dual Port TX Buffer, and 384 byte

Dual Port RX Buffer. The RS-232 transceivers support data rates up to 115.2K bps

and the RS-485 transceivers support data rates up to 921.6K bps.

Connector Pin Assignments (RJ45)

Name Pin # Mode

D+ RS-485 Data + 1

RTS Request To Send 2 Output

TX Transmit Data 3 Output

GND Ground 4

NC No Connect 5

RX Receive Data 6 Input

CTS Clear To Send 7 Input

D- RS-485 Data – 8

Note: DCD, DSR, and RI are inputs that are not brought out on the RJ45 connector.

DSR and DCD are biased active and RI is biased inactive.

Interface Selection

With the unique VersaCom multi-interface connector design, both RS-232 and two-

wire RS-485 signals are always present and active on the RJ45 connectors. Simply

select the appropriate pin out for RS-232 or two-wire RS-485 on each individual

port. The unused interface on each connector should be left unconnected. All inputs

have appropriate biasing to keep them in an inactive state. If the unused interface

pins are connected to a cable, the outputs will attempt to drive the lines while the

inputs will attempt to interpret any voltage on the line as data, which can limit cable

length and may result in communication failures.