Radiometrix Ltd

Page 3

1200buad Modem IC

Mode selection

The mode select bits M0-M3 put NBEK IC in to one of 16 operating modes, including modem mode.

MODE

H=5V, L=0V

0

HHHH

Receive mode

1

HHHL

Un-modulated Transmission for testing carrier frequency, power, spurii

2

HHLH

250Hz (500bps) square wave Modulated Transmission

3

HHLL

1250Hz (2.5kbps) square wave Modulated Transmission

4

HLHH

Pseudorandom NRZ stream modulated Transmission

5

HLHL

Transmitter and Receiver turned ON and OFF periodically at 100ms interval

6

HLLH

RESERVED for future use

7

HLLL

RESERVED for future use

8

LHHH

Continuous Control44 Transmission of Address=0 and Data=D3, D2, D1, D0

9

LHHL

Control44 Transmission of Address=0 and Data=D3, D2, D1, D0

If either Data is changed or RESET (Trigger) switch is pressed.

10

LHLH

Control44 Reception with Momentary Output. (paired with Mode 8)

11

LHLL

Control44 Reception with Latched Output. (paired with Mode 9)

12

LLHH

Transmits CTR44 Test Packet, Receive Echoed Packet (Radar Mode – Master)

13

LLHL

Receive CTR44 Test Packet, Re-transmit it back to Sender (Echo Mode – Slave)

14 (Modem)

LLLH

I1200 type 1200 baud Dumb Modem for bit balanced serial data

transmission

15

LLLL

RESERVED for future use

Notes:

1.

Mode 12 and 13 require Transceiver

2.

In Mode 12, a test packet is transmitted, then the unit switches to Receive mode for 100ms before repeating.

3.

Data sequence of 8 (D3=L, D2=H, D1=H, D0=H), 4, 2, 1 (D3=H, D2=H, D1=H, D0=L) is cycled through with

each transmission.

4.

In Mode 13, the unit idles in Receive mode. When a valid CTR44 burst is received the unit keys up the

Transmitter and re-transmits this CTR44 burst back to sender in Mode 12.