Channel mapping
The SFX2 has a 255 channel capacity.
The first 32 channels are individually programmable (they have their own N register stores).
The remaining channels (32-255) constitute a sequential table
In serial mode the channel is selected by a GOCHAN xxx command
In parallel mode the lowest 8 channels are selected by the state of P1, P2, P3
SFX2 serial configuration commands
2400 baud RS232. 8 bit data, no parity, 1 start bit, 1 or 2 stop bits, No flow control
SINGLE
nnnnn
Set value of N for single channel operation.
N value NOT stored in EEPROM
GOCHAN xxx
GOTEMP xxx
LOAD aa nnnnn
LOADTB nnnnn
LOADMX aaa
Serial select of channel aaa (ch0 to 255), store to EEPROM
Volatile version of GOCHAN
Set value of N for channel aa (channels 0 to 31)
Set value of N for channel 32 (channels 32 to 255 then in sequence)
Set highest permitted (serial selected) channel xxx (others default to ch0)
Set value for R register
RVALUE rrrr
INCREM
SETPAR
i
Set increment value for sequential table (0-7)
Channel selected by 3 bit parallel input (ch0 to 7 only)
(Disable LOCKSM command)
SETSER
DUMPEE
Channel selected by most recent 'gochan' operation
Output entire EEPROM contents (128 unformatted bytes) using the P3 pin as an
output
<cr>
/
Process entry
Clear all buffers
xxx = channel number from 0 to 255
aa = a two digit channel number from 00 to 31
nnnnn = a synthesizer N register value, (up to 65535)
rrrr = the synthesizer R register value, (up to 16383)
i = sequential table step value (0-7)
fRF 21.4MHz
458.525MHz 21.4MHz
25kHz
N
R
17485
25kHz
fTCXO
13MHz
520 (usually)
fcomparison frequency
25kHz
Notes:
1. A pause of at least 50ms must be allowed between command strings (EEPROM programming time)
SINGLE mode does not store the N value in EEPROM. Therefore the unit is inoperative after a
power down until either another valid SINGLE command is received, or mode is changed by a
GOCHAN, SETPAR or SETSER command. SINGLE mode is intended for frequency agile
applications.
2. /SETPAR command should be issued at the end of channel programming to put the module back
into parallel frequency select mode
3. In 458MHz band, channel 12 (458.825MHz) and channel 15 (458.900MHz) are allocated specifically
for fixed alarm and radio keys/vehicle paging applications respectively and should not be used for
general purpose applications.
4. User can modify the frequency table of 128 channels to any desired frequency by changing N, R
values of synthesizer within 2.5MHz of factory set Channel 0 frequency subject to the Radio
Regulatory Band Allocation in the country of intended use.
5. All other frequency, power, analogue input gain and automatic noise squelching adjustment will be
treated as custom variants of the module to be set by factory.
Radiometrix Ltd
SFX2 Data Sheet
page 4
RADIOMETRIX [ RADIOMETRIX LTD ]
