Wireless modem with RS485 at 19200bps air rate

The GDW4192 wireless modem uses RS485 interface to support VHF (136MHz 174MHz, 220MHz-240MHZ) UHF (410MHz-470MHz) user    programming.  With airspeed of 19200 pbs, it is a long-distance wireless data transmission products.

In order to facilitate the user to provide two-way data communication transmission and detection control functions, it adopts a half-duplex working mode.  At the same time, it has a small size, metal casing, good shielding performance and strong anti-interference function.         An integrated amplifier is used internally to ensure good stability and high reliability.

The GDW4192 modem has many options, such as SCADA systems,    RTUs and industrial automation networks, making it ideal for multipoint communication applications.

Specifications

1. General

   (1)Operating frequency range:136MHz-174MHz, 220MHz-240MHZ,410MHz-470MHz

   (2) Channel spacing: 25 KHz

   (3) Number of channels: 60

   (4) ANTENNA IMPEDANCE: 50 Ohm unbalanced

   (5) OPERATING TEMPERATURE: -40 to +70℃

   (6) FREQUENCY STABILITY TCXO: ±2ppm

   (7)OPERATIONVOLTAGERANGE: 12V ( 11Vto 14.5V) DC

   (8) STAND-BY CURRENT: 90mA

2. TRANSMITTER

   (1) RF OUTPUT POWER:1.5 to 25W programmable

   (2) OUTPUT 2ND HARMONIC: less than –65dB

   (3) SPURIOUS EMISSIONS:  less than 0.25uW (30MHz to 1GHz)

   (4) MAXIMUM FREQUENCY DEVIATION: ±5KHz

   (5) REFERENCE OSCILLATOR: TCXO

   (6) RF IMPEDANCE: 50 Ohm unbalanced

   (7) CURRENT DRAIN: 65.0A @25W output power

   (8) FM HUM AND NOISE RATIO: greater than –50dB

   (9) AUDIO FREQUENCY DISTORTION: 3% 1KHz for 3KHz deviation(under normal test condition)

   (10) AUDIO FREQUENCY RANGE: 300Hz to 3400Hz ±2dB

   (11) TRANSMITTER ATTACK TIME: less than 10ms

2. RECEIVER

   (1) TYPE OF RECEIVER:Crystalcontrolled double, super heterodyne

   (2) INTERMEDIATE frequency: 45MHz(1st IF), 455KHz(2nd IF)

   (3) SENSITIVITY: Better than 0.2uV @12dB SINAD

   (4) SQUELCH SENSITIVITY:0.3uV

   (5) ADJACENT CHANNEL SELECTIVITY: greater than –65dB

   (6) SPURIOUS AND IMAGE REJECTION: greater than –65dB

   (7) OUTPUT AUDIO DISTORTION: 3% at 1KHz for ±5KHz deviation

   (8) FM HUM AND NOISE RATIO:  greater than 40dB

3. Data and Interface

   (1) MODULATION: 4-FSK

   (2) AIR RATE: 19200bps programmable

   (3) INTERFACE BAUD RATE: 600 - 19200 bps programmable

   (4) INTERFACE DATA BIT: 8 bit

   (5) INTERFACE PARITY BIT: None / Even / Odd

   (6) INTERFACE STOP BIT: 1 / 2  bit