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© Sealevel Systems, Inc. 1102 Manual | SL9135 6/2021
Introduction
The Sealevel Systems IC485+
is a single channel RS-232 to RS-422/485 asynchronous converter. It
provides one field selectable RS422/485 serial port supporting asynchronous data rates up to 115.2K
bps.
The IC485+ is self-powered allowing it to correctly drive multi-drop RS-485 networks.
Configure the port as RS422 for long distance device connections up to 4000ft. where noise immunity and
high data integrity are essential. Select RS-485 and capture data from multiple peripherals in an RS485
multi-drop network. Up to 31 RS-485 devices can be connected to automate your data collection.
In RS-422 and RS-485 Auto modes, the card works seamlessly with the standard operating system serial
driver. Two additional methods are provided to control the communication line in RS-
485 mode. The “Data
Enable” mode uses the transmitted data to enable the transmitter and requires no
software drivers. This
mode has limitations that will be discussed in more detail later. The “RTS Enable” mode uses the UART
modem control signal R
TS to control the communication line and requires the Sealevel Systems’ serial
driver.
