RS232 RF module 433M VT-DTMPA-232-433 GFSK modulation RF module

Description

The VT-DTMPA-232-433M module is designed as a wireless sub module for wireless communication between devices like controls, POS systems, data collectors etc. It offers several addressing modes and relieves the host systems of wireless-specific task such as checksum calculation, address resolution.

It can be deployed whenever the wireless exchange of data packet between two or more parties is required.

A RS232 interface whose data rate is adjusted flexibly is available for communicating with the host systems. The data rate can be adjusted from 2.4kbps to 115.2kbps.

Thanks to its small size and the external SMA antenna connector, the module can easily be installed in existing systems without any external circuits.

Key Features

GFSK modulation

 Communication distance up to 1000 meter

Supports addressing transparent communication

 Auto add preamble, checksum, address information

Supports setting mode to configure parameters Channel, Interface

Band Rate, Radio Data Rate, Output Power, Source Address,

Destination Address

 RS232 interface

Half Duplex communication, 8N1 format

 5.0V DC Power Supply

 Consumption: Transmit <250mA; Receive <55mA

 Optional Antenna

Application

 Automatic Meter Reading

 Wireless Sensor Network

Data Collector

 Controls, Remote Controls

 POS Systems

 Building Automation

 Android Controls

Specification

Testing condition:Ta=25°C, VCC=5.0V

Parameter Value Condition/Note

Center Frequency 433MHz Programmable, up to 6 channels

Modulation GFSK Customize for ASK/FSK/OOK/MSK

Output Power Max: 25dBm Programmable, 0-25dBm

Sensitivity -110dBm 2.4kbps

Radio Data Rate Max 500kbps Programmable, 2.4-500kbps

RS232 Interface Rate Max 115.2kbps Programmable, 2.4-115.2kbps

Protocol Format 8N1 Customizable

Data Buffer Tow 100 bytes

Transmit Current <250mA Depend on output power

Receive Current <55mA

Distance 1000 meter Open area; Max output power; 2.4kbps Radio Date Rate

Operate Humidity 10%~90%

Operate Temperature -40℃~85℃

Input Voltage 5.0VDC±10% ±100mV

Antenna 50ohm

Size

Note:

1. Noted that higher radio data rate causes of shorter communication disdance.

2. Noted that higher radio data rate causes of lower sensitivity.

3. Noted that lower input voltage causes of lower output power.

4. Noted that the operate temperature out of range -40℃~85℃ will influence the center frequency.

5. Be sure to use a match antenna and mount it in the right way.

6. The environment will influence the communication disdance much.

Module Description

Device Type Description

Interface VCC Input Voltage DC5V±10%

GND GND Connect to the system GND

RESET Reset signal input TTL level, 10ms low level to reset the module

SLEEP Sleep Not available

RXD Serial port RS232-RXD

TXD Serial port RS232-TXD

SET Setting Not available

Reset Key RESET Signal Input Reset the module

Setting Switch Input Switch the module to work on setting mode

D1 LED1 Indicating the communicate state

D2 LED2 Indicating the communicate state

SMA connector Antenna Connect external antenna of 50ohm

Input Voltage

The input voltage of the module ranges from 4.5V to 5.5V. A clean supply voltage is needed for the module to function correctly.

Operating Modes

The device can be used in the following operating modes:

1. Transparent, Buffered data transceiver

2. Setting Mode

The operating mode can be selected by the setting switch state. If the setting switch keeps on the “SET” state, the module will run on the setting operating mode after power up. Otherwise, if the setting switch keeps on the “TRANSPARENT” state, the module will run on the transparent operating mode after power up. The setting switch state shows as Fig 1.

Fig 1 Switch States

Transparent Mode

In this operating mode, data of the transmitter module is received via the RS232 interface and initially buffered. As soon as specific conditions are met (timeout or data buffer be filled full), the radio telegram is generated with preamble, Sync word, and Checksum and address information (modules address are the same). As soon as the transmission of a packet has begun, the RS232 interface cannot receive any further data.

The receiver module receives the wireless telegram and transmits the payload characters via RS232 interface. As long as receiver module is busy in sending characters via the RS232 interface, wireless telegram reception is not possible. For example, this effect is noticeable when sending a long data packet and subsequently a short data packet. In this case, the receiver module may still be busy in sending the first packet via RS232 interface and the second packet may be lost.

Setting Mode

This operation mode primary serves module configuration parameters.

In this operating mode, there are menus to guide the setting commands and configuration parameters. In order to setting the module, be sure to install a com assistant like Commassistant, Terminal etc. We will offer the Terminal com assistant.

The configuration parameters are saving to the on-chip flash after access the exit command. The configuration parameters take affect after reset the module when exit the setting mode. The setting commands and configuration parameters show on the Tab 1.

Tab 1 Setting Commands and Configuration Parameters

Commands Command Function Configuration Parameters

U Setting the RS232 interface band rate 1 - 2400 bps

2 - 9600 bps (Default)

3 - 19200 bps

4 - 38400 bps

5 - 57600 bps

6 - 115200 bps

D Setting the radio data rate 1 - 2400 bps

2 - 9600 bps

3 - 19200 bps

4 - 38400 bps

5 - 250000 bps (Default)

6 - 500000 bps

C Setting the channel 1 - Ch=1 - 430 MHz

2 - Ch=2 - 431 MHz

3 - Ch=3 - 432 MHz

4 - Ch=4 - 433 MHz (Default)

5 - Ch=5 - 434 MHz

6 - Ch=6 - 435 MHz

P Setting the output power 1 - -10 dBm

2 - -5 dBm

3 - 0 dBm

4 - +5 dBm

5 - +7 dBm

6 - +10 dBm (Default)

S Setting source address Address ranges from 0x00 to 0xFF (Default 0xFF)

E Setting destination address Address ranges from 0x00 to 0xFF (Default 0xFF)

X Exit setting mode The configuration parameters be save to the on-chip flash after access this exit command

The RS232 interface band rate is configured to 9600bps in the setting mode. For example, to set the radio data rate to 500kpbs, the setting steps are:

1. Connect the module to a computer.

2. Run the com assistant Terminal and select the right COM Port, band rate set to 9600bps, 8N1 format.

3. Switch the setting switch to the “SET” state and reset the module. Setting menu display on the Terminal.

4. Enter “D” command and send. A radio data rate list display on the Terminal.

5. Enter “6” and send to select the 500kbps radio data rate.

6. Enter “X” command to exit setting mode. Parameter configures success.

From Fig 3 to Fig 6 show the configuration process.

Fig 2 Commands Menu Fig 3 Radio Data Rate List

Fig 4 Select the 500kpbs Fig 5 Exit Setting Mode

Addressing

Addressing is available. The transmission module generated the Source Address and the Destination Address information to the wireless telegram. The receiving module will only deliver the data to the host system via RS232 interface if both the destination address and source address correspond to the source addresses and the destination address itself.

Start-up

In the factory state, the modules are immediately ready for operation. Default in transparent operating mode. The default parameters are:

 RS232 interface Band Rate: 9.6kbps

Radio Data Rate: 250kbps

 Channel: 433MHz

 Output Power: +10dBm

 Source Address: 0xFF

Destination Address: 0xFF