M48-434-NIM2 Datasheet, PDF (1/11 Pages) Radiometrix Ltd – UHF NBFM RS232 radio modem

Hartcran House, 231 Kenton Lane, Harrow, Middlesex, HA3 8RP, England
Tel: [phone], Fax: [phone], www.radiometrix.com
M48-434-NiM2
Issue 1, 29 October 2012
UHF NBFM RS232 radio modem
The M48-434-NiM2 presents M48 modem IC combined
with a NiM2 radio module and suitable interface
circuits, power supplies, connectors to provide a
complete RS232 radio modem interface. Optionally,
the board can be housed in an EAS80 extruded
aluminium housing. In the simplest case, a pair of
these units (with suitable aerials and power supplies
connected, of course) can be connected directly to
the serial ports of a pair of industrial PCs and the
resulting wireless data link used without any further
installation or programming.
The M48A is a simple, half duplex, transparent data link
device. It provides a basic 4800 baud RS232 compatible
path without the user needing to format, code, detect or
otherwise worry about modifying his existing datastream or
providing extra 'control' lines. The user interface datarate,
addresses and operating parameters can all be easily re-
programmed via the serial port.
Figure 1: M48A-434.065-NiM2
It ought to be emphasised that the M48A is a very simple, easy to use, device. As supplied, it operates as a
4800 baud, transparent half-duplex data link. If required, there is an extensive range of programming
options, allowing user interface speed from 1200 to 76800 baud, hardware flow control, one to one, one to
many and broadcast addressing options, and acknowledge/re-transmit error handling protocols. Simple store
and forward repeater operation is also provided.
A good demonstration can be had by connecting a pair of PCs by their serial ports and a null-modem cable,
and setting up terminal emulators (4800 baud, asynchronous, local echo on) on both computers. Confirm
that good RS232 communication is present, and then replace the cable with a pair of M48A modems. The
resulting 'radio teletype' can be entertaining to play with.
Features
Usable range over 500m (@ 10mW RF power)
5kbps pulse duration coded protocol
Synchronisation codes and checksum to reduce false triggering on noise
Programmable transmit address and four receive addresses
Programmable timing parameters (preamble length, etc)
Programmable serial modem baud rate (1200 - 76800 bps, half-duplex)
Addressable point-to-point and point to multi point
Packet acknowledge/resend (ACK) mode
Store and forward repeater function
Applications
PDAs, organisers & laptops
Handheld / portable terminals
Remote operated vehicles
Data loggers
In-building environmental monitoring and control
Industrial (SCADA) telemetry and M2M systems
Fleet management, vehicle data acquisition
Radiometrix Ltd, M48A-434-NiM2 modem manual
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