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DS Storm-b May 08

©2008 Reg. No. 227 4001, ENGLAND

Page 3

Configuration

The configuration of the STORM modem may be changed by placing it in Configuration mode, then sending a

set of configuration data bytes to the module on the Tx pin.

To place the STORM modem in Configuration mode the user needs to send “+++” (three plus characters)

within the 10mS timeout for each character. The STORM responds by returning it’s current set of

Configuration data bytes. The STORM Modem is now on Configuration mode.

To exit Configuration mode the user needs to send “---“ (three minus characters) within the 10mS timeout for

each character. The STORM will not return a response. The STORM is now in data mode.

Byte

Name

Description

Default Supplied Value

0

MSB

7E hex

1

7E hex

2

7E hex

3

Destination Address

LSB

7E hex

4

MSB

7E hex

5

7E hex

6

7E hex

7

STORM Address

LSB

7E hex

8

RF Channel

100 kHz step offset from 422.4MHz

107 (433.1MHz)

0 = -10dBm

1 = -2dBm

2 = +6dBm

9

Tx Power

3 = +10dBm

0 (-10dBm)

10

Tx data packet size

3 – 31 bytes

30 bytes

11

Rx data packet size

3 – 31 bytes

30 bytes

The RF Channel is calculated as:

433 MHz working frequency:

Config value (decimal) = (desired RF frequency - 422.4MHz) * 10

868 MHz working frequency:

Config value (decimal) = [(desired RF frequency / 2) - 422.4MHz] * 10

Please Note, the calculated value must be converted into hexadecimal format.

While the STORM is in configuration mode it will send the current configuration back to the host each time a

data packet is received. To retrieve the current configuration without changing any options the host can send a

single byte to the modem and wait for the response.

It is not necessary to send all configuration bytes to the modem, but all data sent must be valid. For example

to change the destination address the host may just send four bytes. Configuration data excluded from the end

of the data stream will be unchanged. The STORM modem will accept a short configuration when a 10ms

timeout after the last byte sent to the module expires. This allows for the host to easily change the destination

address of the RF data packet, thus enabling one STORM to send individual data to several different recipient

modules.

A destination address of 00000000 will reset the STORM to the default settings shown above.

RF data packets received by the STORM with the embedded destination address which matches the STORM

address will be accepted, processed and passed to the host, all of the RF data packets will be ignored.

When configuring the destination or STORM address an incorrect number of bytes for an address will leave

the current address unchanged.

An invalid Transmitter Power or Packet Size setting will leave the current setting unchanged.