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Cooper Bussmann 945U-E Wireless Ethernet Modem & Device Server User Manual
Rev Version 2.14
The power requirements of the 945U-E unit are shown in the following table.
12Vdc
24Vdc
Quiescent
300 mA
160 mA
TX @100 mW
370 mA
190 mA
TX @ 400 mW
410 mA
210 mA
A ground terminal is provided on the back of the module. This terminal should be connected to the main ground
point of the installation in order to provide efficient surge protection for the module (refer to the Installation
diagram).
2.3 Serial Connections
RS232 Serial Port
The serial port is a 9-pin DB9 female and provides for connection to a host device as well as a PC terminal for
configuration, field testing, and factory testing. Communication is via standard RS232 signals. The 945U-E is
configured as DCE equipment with the pinouts described below.
Hardware handshaking using the CTS/RTS lines is provided. The CTS/RTS lines may be used to reflect the status
of the local unit’s input buffer. The 945U-E does not support XON/XOFF. Example cable drawings for connection to
a DTE host (a PC) or another DCE hosts (or modem) are detailed in Figure 13.
Figure 13 Serial Cable
DB9 Connector Pinouts
DB9 Connector Pinouts
Pin
Name
Direction
Function
1
DCD
Out
Data Carrier Detect
2
RD
Out
Transmit Data – Serial Data Output (from DCE to DTE)
3
TD
In
Receive Data – Serial Data Input (from DTE to DCE)
4
DTR
In
Data Terminal Ready
5
SG
Signal Ground
6
DSR
Out
Data Set Ready - always high when unit is powered on
7
RTS
In
Request to Send
8
CTS
Out
Clear to Send
9
RI
Ring Indicator
RS485 Serial Port
The RS485 port provides for communication between the 945U-E unit and its host device using a multi-drop cable.
Up to 32 devices may be connected in each multi-drop network.