CL4424 User’s Manual
Figure 7- DCE to DCE Interface
OEM Host
CTS | | | | | | |
RTS | | | | | | |
RXD | | | | | | |
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TXD | | | | | | | |
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GND | | | | | | |
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DCD | | | | NC | NC | |
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DSR | | | | | | |
DTR | | | | | | |
RI | | | | NC | NC | |
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CL4424 Modem
CTS
RTS
TXD
RXD
GND
DCD
DSR
DTR
RI
Crossover Cable
Note: The Straight Through Cable provided with the CL4424 has female connectors on both ends and the Crossover cable has a male connector at one end and a female connector at the other end. Please use a male-to-male adapter or female-to-female adapter wherever required. Using a null modem adapter with a Crossover cable is equivalent to using a Straight Through cable.
2.2RS-485 (2-wire Half Duplex)
The RS-485 interface uses a Differential Data Transmission that can help nullify the effects of ground shifts and induced noise signals that can appear as common mode voltages on a network.
The CL4424 implements a RS-485 (2-wire Half Duplex) multi-drop interface. Typically, a RS-485 bus will consist of a master and several slaves. The nodes will 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 CL4424 does not have a RS-485 address, therefore, it will transmit all RS-485 traffic over the RF. Conversely, as soon as a CL4424 receives a packet over the RF, it will transmit the packet over the RS-485 bus.
Note: When using RS-485 (2-wire Half Duplex), a RS-485 to RS-232 converter is required to configure the unit. AeroComm recommends a B&B Electronics 4WSD9R converter to translate RS-485 to RS-232.
