User's Manual

RV-M50-EC Technical Manual

2. Configuring the Daisy ISM

2.1 Overview

The UART serial port on the unit is used to send and receive data over the air, as well as to configure the

RF modem. In standard transparent-link operation, the user sends serial data into the TxD pin of the

user port, and this data is transmitted over the air. Received data from another RF modem is output to

the user via the RxD pin of the user port. This is the default operating condition of the RF modem. No

special characters, hardware control lines, or timing is required to operate the Daisy Modem.

By default, the serial port is set to 38400 baud, 8 data bits, 1 stop bit, no parity bit.

If the Daisy is configured as a GPS transponder, the serial port need not be connected to anything. The

internal GPS will initiate the transmissions of position and status. The serial port may be connected to

receive other GPS reports or send and receive additional data.

There is also a Command Mode used to program and configure the modem. In the Command Mode, the

modem accepts commands via the serial port TxD pin. The commands can be used to change certain

internal parameters of the modem as well as to read-out the current configuration and diagnostic

statistics.

The modem also supports Raveon’s Wireless Modem Exchange (WMX) protocol for commanding and

messaging. WMX is ideal for fully automated control and tighter integration. For more information, see

the WMX Protocol Description document and the Raveon Tech Note “Rapid Radio Configuration using

WMX”.

2.2 Command Mode

Command Mode is used to program and configure the modem. This mode is separate from data mode

and will not transmit received data over-the-air, instead executing commands detailed in this manual.

Command Mode Encoding and Line Format

In Command Mode, all characters are ASCII encoded. All output lines will use the standard network line

ending, CR+LF (ASCII 0x0D followed by ASCII 0x0A).

Inputs lines may use either CR, LF or CR+LF line endings.

Entering Command Mode

The modem may be put into a Command Mode, by entering a sequence of three plus characters (+++),

called the Entry Sequence. To keep the modem from unintentionally entering the Command Mode

because of the Entry Sequence occurring in a stream of data entering the modem, there must be a

pause in the data stream before the Entry Sequence as well as a pause afterwards. If either pause is

missing, the modem will not enter the command mode. The pause length is configurable, by default it is

500ms.

When the modem first enters the Command Mode, it will output the base model number along with the

OK sequence: