Radiometrix Ltd

CXT/CXR – Multi channel Remote Controller Data Sheet

page 4

Pin description –CXT

Pin

Name

Function

1a

Vcc

3.1 – 15V power supply

2a

0V

Ground

3a

N_TXE

Transmit Enable (active low)

4a

TXD

Link to 4b

1b

SI

Serial frequency programming / configuration

1

2b

A (in)

Main (latching) input

3b

B (in)

Second (cancel) input

4b

T_out

Link to 4a

Notes:

1.

Serial programming is by an inverted, CMOS logic level, 2400 baud RS232 datastream applied to

the SI pin.

2.

TXE has a 100kΩ pullup to Vcc

3.

Do not exceed 3v logic levels on SI, A or B.

4.

SI input has pullup (50K) to 3v internal rail.

5.

A and B inputs have pullups (50K) to 3v internal rail. (A, B inputs: active low)

6.

CX versions can be identified by the presence of C7, on the underside of the LMT series TX board

Figure 3: CXT footprint (top view)