Radiometrix Ltd
LMT2/LMR2 Data Sheet
page 6
Serial interface commands
2400 baud RS232. 8 bit data, no parity, 1 start bit, 1 or 2 stop bits.
Serial data is sent to the unit on one of the parallel channel select pins (P0). It is very important that
the unit does not 'decode' switch bounce in ordinary operation as a command string, or spurious re-
writing of the e2prom will result. For this reason the user must send the 16 character string
ENABLESERIALMODE (followed by a carriage return) to activate the serial command mode before
sending any of the command strings listed below. Command mode is disabled on power down, or on
reception of a # character. To successfully program the unit, it must be enabled ('RXE high (rx) or TXE
low (tx)).
GOCHAN aa
Serially select channel aa, where aa is ch0 to ch31
LOAD aa nnnnn
Set value of N register for channel aa, where aa is Channels 0 to 31
SETPAR
Channel selected by 4 bit parallel inputs (ch0 to ch15 only)
SETSER
Channel selected by most recent GOCHAN operation
RVALUE rrrr
Set value for R register
SINGLE nnnnn
Set value of N for single channel operation.
N value NOT stored in EEPROM
<cr>
Process entry
/
Clear all buffers
#
Disable command mode
aa = a two digit channel number from 00 to 31
nnnnn = synthesizer N register value (up to 65535)
rrrr = synthesizer R register value (up to 16383)
17356
25
900
.
433
=
=
=
kHz
MHz
f
f
N
cing
Channelspa
RF
TX
kHz
MHz
f
f
R
cing
channelspa
TCXO
25
13
=
=
, So R=520
16500
25
4
.
21
900
.
433
4
.
21
=
−
=
−
=
kHz
MHz
f
MHz
f
N
cing
Channelspa
RF
RX
Note: 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.