Specifications, Technical description – Impulse 1102 User Manual
Page 11

Technical Description
Sealevel Systems IC485+ Page
9
Technical Description
The Sealevel Systems IC485+ converts an existing RS-232 serial port into a field selectable RS-422/485 port for
industrial automation and control applications.
Connector Pin Assignments
RS-232 Signals (DB-25 Female)
Signal Name Pin
#
Mode
GND Ground
7
RD Receive
Data
3 Input
CTS
Clear To Send
5
Input
DSR
Data Set Ready
6
Input
DCD
Data Carrier. Detect
8
Input
RI Ring
Indicator
22
Input
TD
Transmit Data
2
Output
RTS
Request to Send
4
Output
DTR
Data Terminal Ready
20
Output
Note: These assignments meet EIA/TIA/ANSI-232E DTE
Technical Note: The modem control signals are biased in the following fashion: RTS and CTS are connected,
DTR is connected to DCD and DSR, and RI is tied inactive.
RS-422/485 Pin Assignments (6 Position Screw Terminal)
Signal
Name
Pin
# Mode
RDB
RX+
Receive Data Positive
1
Input
RDA
RX-
Receive Data Negative
2
Input
TDB
TX+
Transmit Data Positive
3
Output
TDA
TX-
Transmit Data Negative
4
Output
GND GND
Ground
5
SHIELD SH
Shield
6