5.11.2.1Serial Data From Wireless modem (DFM1)

DFM1 is an output signal that the wireless modem uses to send data via UART1 to the host application.

The electrical characteristics of this level-shifted signal are described in section 5.3.1.

5.11.2.2Serial Data To Wireless modem (DTM1)

DTM1 is an input signal, used by the application to send data via UART1 to the wireless modem.

The electrical characteristics of this level-shifted signal are described in section 5.3.1.

5.11.3 Control Signals (RTS1, CTS1, DTR1, DSR1, DCD1, RI)

Depending upon the user application, some, all, or none of the control signals may be needed. Each of the control signals can alternatively be configured as a general purpose IO. When hardware flow control is not used in communications between the application and the wireless modem, some applications may require RTS and CTS to be connected to each other at the wireless modem. Users should familiarize themselves with the specific implementation of their UART.

UART1 converted signals, together with GND, DTM1 and DFM1 form a 9-pin RS232 data port.

The electrical characteristics of these level-shifted signals are described in section 5.3.1.

5.11.3.1Hardware flow control RTS1 and CTS1

RTS and CTS provide a hardware flow control mechanism.

5.11.3.2Request to Send (RTS1)

RTS is used to condition the DCE for data transmission. The default level is high by internal pull up. The application must pull RTS low to enable data transmission from the wireless modem. Similarly, the wireless modem asserts CTS low, indicating it is ready to receive data transmission from the host.

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