CL4490 Hardware Integration Guide
Version 1.0
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13
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Table 5: CL4490-PRO RS232 Pinout (as defined in the CL4490-PRO)
DB9 Pin Signal Name
I/O Description
Details
1
DCD
O
Data Carrier Detect
Carrier Detect Signal. Connects
to DSR (pin 6).
2
TXD (RXD with
respect to DTE)
O
Transmitted Data
Serial Data (modem to host).
3
RXD (TXD with
respect to DTE)
I
Received Data
Serial Data (host to modem).
4
DTR
I
Data Terminal Ready Determines if modem is ready
for operation.
5
GND
-
Ground
Ground
6
DSR
O
Data Set Ready
Connects to DCD (pin 1).
7
RTS
I
Request To Send
Provides RTS Flow Control.
8
CTS
O
Clear To Send
Provides CTS Flow Control.
9
NC
-
No Connect
No connect.
Note: Refer to
Interfacing to Other RS232 Equipment
for more information.
RS485 (2-wire)
The RS485 interface uses a Differential Data Transmission that helps nullify the effects of ground shifts and
induced noise signals that can appear as common mode voltages on a network.
The CL4490-PRO implements a RS485 (2-wire Half Duplex) multi-drop interface. Typically, a RS485 bus
consists of a master and several slaves. The nodes have unique addresses and can send addressed packets to
specific nodes. Because the bus is half duplex, no two nodes should try to talk at the same time. The CL4490-
PRO does not have an RS485 address; therefore, it transmits all RS485 traffic over the RF. Conversely, as soon
as a CL4490-PRO receives a packet over the RF, it transmits the packet over the RS485 bus.
Figure 9: RS485 Half Duplex and Termination DIP Switch Settings
Table 6: CL4490-PRO RS485 Pinout
DB9 Pin
Signal Name
Description
1
-
No Connect
2
TR-
Serial Data transmitted to & received from radio
3
-
No Connect
4
-
No Connect
5
GND
Ground
6
-
No Connect
7
-
No Connect
8
TR+
Serial Data transmitted to and received from radio
9
Power
Optional Power Input
1
1.
An internal jumper must be configured in order to use power over Pin 9.
DB9 female
connector
DB9 female
connector
