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CompactRF

Operating Manual: Chapter 3 Modes of Operation 15

The escape sequence will not

be accepted unless both the

CompactRF

and the

terminal are set to the same

baud rate

DATA

MODE

SLEEP

MODE

COMMAND

MODE

ESC \SLEEP

\SLEEP

ESC \SLEEP

\SLEEP \CONFIG

Figure 5a - Menu

Interface State Diagram

DATA

MODE

SLEEP

MODE

COMMAND

MODE

\SLEEP

(ATA or ATO Command)

DTR or

Escape Sequence

\SLEEP

Figure 5b - AT Interface

State Diagram

The modem will now attempt to communicate with other CompactRF

modules. While in Data Mode, the modem will communicate through the

serial port at the same baud rate as was last used in Command Mode

To return to Command Mode, you can either:

• Send the escape sequence. (The escape sequence consists of 1 second

of inactivity, followed by the characters ‘+++’ followed by another

second of inactivity.); or,

• Toggle the DTR line (depending on the &D parameter see pg 11).

The escape sequence must be issued at the baud rate that the modem has

been set to. If the modem is set to 19200 baud, and the escape sequence is

issued at 9600 baud, for example, the modem will not recognize it, and will

not go into Command Mode.

3.3.2 Switching Between Menu Interface and Data Mode

When configured for Menu Interface operation, the CompactRF may be

placed into Command Mode from Data Mode by momentarily asserting the

\Config line. This line runs out to a pushbutton on the development board.

Press this button and wait for the menu interface to appear on the screen.

The terminal must be set to 9600 baud when using the menu interface.

To switch back to Data Mode, from the main menu, hit the ESC key. You

should see the response “Running...” The modem will run in Data Mode at

the baud rate setting defined by Menu Item 2) Serial Baud Rate.

3.4 Sleep Mode

As mentioned at the beginning of this chapter, the CompactRF has a sleep

mode of operation. Figure 5 is a state diagram representation of the three

modes of operation. Figure 5a is the menu interface state diagram, and

Figure 5b is the AT interface state diagram. The CompactRF enters into

Sleep Mode when \SLEEP is asserted (active low). The module remains in

Sleep Mode until this line is deasserted. See Chapter 2 for timing

information. When in Sleep Mode, the module drives all outputs pins (Pins

6-11,23-25,27) at their inactive levels.

It is possible to enter into Data Mode at a different baud rate from what is

currently being used in Command Mode by issuing the command

ATS102=x, where x is one of the valid baud rates. Care must be taken

when setting the baud rate in this manner. If you issue another AT string

after attempting to set the baud rate using ATS102 <ENTER>, the modem

will again autobaud and automatically revert to the baud rate of the host

equipment. For example, if your equipment is running at 9600 baud and

you wish to set up the modem to run at 19200 baud, the following command

line entry would achieve this:

ATS102=2&WA <ENTER>

The first part (S102=2) sets the baud rate to 19200. The next characters

(&W) write this baud rate to memory. The last character (A) puts the

modem into Data Mode. Once in Data Mode, the modem is unable to

autobaud, and is fixed at 19200 baud. By combining several commands into

one command line entry, and then immediately putting the modem online,

the modem is not given a chance to autobaud back to 9600.