STE BK77 Скачать руководство пользователя страница 13

 

 

 

STE  sas     Milano - ITALY 

 

Pag. 13 of 14 

 

 
 

NT and NR number calculation  ( BK 77x )

 

 
“NT” and  “ NR” are 16 bit binary numbers used  to program the  “PLL”  N-divider in TX 
and in RX  mode. 
 
“NT”  and  “NR”  are entered into the radio in hexadecimal format. The  “MSB” bit of  “NT” 
is used as a flag to program the RF output power :  1 = HIGH POWER ,   0 = LOW POWER. 
 
 

“NT” is calculated dividing the required TX frequency  (KHz)  by 12.5  ( 12.5 KHz 
is the frequency programming step ). 

 

“NR” is calculated from the required RX frequency  (KHz)  subtracting  21400              
(21400 KHz is the first conversion intermediate frequency ) and then dividing by 
12.5. 
The “PLL” IC ( a FUJITSU MB15E03) when programmed for 64/65 prescaler 
divide ratio, has an internal register ( “N” register ) where bit n° 6  of “N” word 
must be set to 0 and ignored. To do this a 0 bit must be inserted as n° 6 bit into the 
calculated  “NT” and “NR” binary numbers. 

 
A) “NT” 

calculation 

 

 

 

1)  nT number :   nT =  TX 

 FREQ.

( KHz )  /  12.5 

2)  Write down nT in binary format  ( 16 bit ). 
3)  Insert a 0 into nT as bit  n° 6. 
4)  Write down the new binary number and eliminate the  “MSB” 
5)  Convert in Hexadecimal format. 
6)  For  “HIGH POWER” the MSB bit of the first Hex  number must be set to “1”. 

 
B) “NR” 

calculation 

 

 

1)  nR number :  nR =  [ RX 

 FREQ.

(KHz)  - 21400 ] /  12.5 

 

2)  Repeat point 2 to 5  as above. 

 
EXAMPLE : 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
A) TX 

FREQ. 

= 433.7125  MHz 

 

 

nT  

NUMBER 

 =  34697  =   8789 H  =  

1000 0111 1000 1001 

 

New bin. Number with 0 at n° 6 bit = 

1 0000 1111 0000 1001 

 NT 

 NUMBER 

 ( LOW POWER)       = 

  0000 1111 0000 1001 

=  

0F09 H

 

 NT 

 NUMBER 

 ( HIGH POWER)      = 

  1000 1111 0000 1001 

=  

8F09 H

 

 
B) RX 

FREQ. 

= 433.7125 MHz 

 

 

 

nR  

NUMBER 

 =  32985  =   80D9 H  =  

1000 0000 1101 1001 

 

New bin. Number with 0 at n° 6 bit  = 

1 0000 0001 1001 1001 

 NR 

 NUMBER 

  

  0000 0001 1001 1001 

=  

0199 H

 

 

 

 

“CH” command format to program channel n° 2 on 433.7125 MHz ( transmit and 
receive) , high power :

 

                CH  ( 1,8F09,0199 )  [ CR ] [ LF ]  

Содержание BK77

Страница 1: ...MUNICAZIONI Via Maniago N 15 20134 Milano Italy Tel 39 02 2153524 2153525 2157891 Fax 39 02 26410928 www stecom com ste stecom com PLL NBFM SYNTHESIZED VOICE DATA TRANSCEIVER 433 05 434 79 MHz ISM BAN...

Страница 2: ...n with a 25 KHz channel separation The programming frequency step is 12 5 KHz A BK77A5 The BK77A5 is designed in accordance with CEPT ERC REC 70 03 recommendation Annex 1 Non specific short range devi...

Страница 3: ...B 5R A 5V IC3A TP XF4 CER DISCR Q4 IF AMP Q5 IF 21 4 MHz XF2 2 LOCAL CER FILT OSC 2 L O ADJ Q2 AMP Q1 LNA XF1 FILTER T R D1 D2 IC9 3V 5V 5R Q15 Q14 5T Q17 TXD Q16 PTT 600 S3 IC7B AUDIO LEVEL ADJ COMP...

Страница 4: ...UTPUT POWER a BK77A5 low high b BK77B5 low high 10 80 80 400 15 100 100 500 mW mW mW mW 3 SPURIOUS EMISSION 40 36 dBm FM DEVIATION 3 5 KHz R T SWITCHING TIME 5 10 ms 4 MODULATION VOICE MODE PM MOD VOI...

Страница 5: ...SQUELCH LEVEL 2 L O FREQ ADJ VCO TUNE TP1 FREQ ADJ n 1 n 20 F1 FUSE 19 20 17 18 15 16 13 14 11 12 10 9 8 7 5 6 4 3 2 1 D V DATA VOICE CHD CHC CHB CHA RF CHANNEL PRO PRI PROGRAMMING TTL LEVEL 5 VDC RS...

Страница 6: ...d TX power HI LO Fig 6 MCU to transceiver typical connection Data mode J1 2 1 3 5 7 9 11 13 15 17 19 20 5 VDC 4 6 MCU S MONITOR CAR DECT PTT RXD TXD CTS D C B A DATA VOICE ARX RSI CD CHANNELS SELECT J...

Страница 7: ...onnections in Voice mode analogue signals J1 2 1 3 5 7 9 11 13 15 17 19 20 5 VDC 4 6 MCU PTT RXD TXD CTS CHD CHC CHB CHA DATA VOICE ARX RSI CD J1 2 1 3 5 7 9 11 13 15 17 19 20 5 VDC 4 6 S RX AUDIO OUT...

Страница 8: ...ag 8 of 14 Fig 9 Transceiver total control DATA mode by external host microcontroller TX RX frequency power J1 2 1 3 5 7 9 11 13 15 17 19 20 4 6 MCU RXD TXD TX RX DATA VOICE ARX MONITOR RSI S CD CAR D...

Страница 9: ...illator see block diagram Fig 2 to provide a flat response from 4 8 KHz down to DC Note In DATA operating mode the TX VOICE analog input ATX J1 pin n 9 is not disabled Signal on ATX input must be avoi...

Страница 10: ...operation on default channel n 1 Serial mode programming software is available for the BK7XX transceiver for further details contact the STE sales office TABLE 1 CHANNEL CHD CHC CHB CHA 1 1 1 1 1 2 1...

Страница 11: ...exchanged between the radio and the PC as ASCII characters programs such as HyperTerminal can be used to send and receive the ASCII strings of characters Serial protocol format 9600 Baud 8 data bit 1...

Страница 12: ...ERATION MODE ASWER FORMAT XXXX CR LF RADIO STATUS T TRANSMISSION R RECEPTION RADIO MODE V VOICE D DATA SELECTED CHANNEL HEX FORMAT 0 TO F X 4 HEX DIGITS NT OR RT NUMBER CR CARRIAGE RETURN ASCII CODE 0...

Страница 13: ...o this a 0 bit must be inserted as n 6 bit into the calculated NT and NR binary numbers A NT calculation 1 nT number nT TX FREQ KHz 12 5 2 Write down nT in binary format 16 bit 3 Insert a 0 into nT as...

Страница 14: ...2 433 2625 L 0EA5 0135 4 3 433 2875 L 0EA7 0137 5 4 433 3125 L 0EA9 0139 6 5 433 3375 L 0EAB 013B 7 6 433 3625 L 0EAD 013D 8 7 433 3875 L 0EAF 013F 9 8 434 3125 L 0F39 0209 10 9 434 3375 L 0F3B 020B...

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