M48A-000-DIL RADIOMETRIX, M48A-000-DIL Datasheet - Page 7

• Manufacturer Part Number: M48A-000-DIL
• Description: IC, CONTROLLER, SERIAL MODEM, 20DIP
• Manufacturer: RADIOMETRIX

Specifications of M48A-000-DIL

• Baud Rate: 4800baud
• Supply Voltage Range: 4.5V To 5.5V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: DIP
• No. Of Pins: 20
• Controller Type: MOSFET
• Data Format: Asynchronous

Notes: Variables rr and tt are all two digit hexadecimal values (00 to FF)
Extended mode (MEXT) is used with repeater systems. With TRIES set to two or more, this mode sends
each packet several times (increasing the chance of reception at extreme range).
Lastly, the M48 has an ' AKN/re-transmit ' mode. In this case, after each packet is sent, the receiving unit
sends back an knowledge message. If this message is not successfully decoded, at the transmitting end, it
will re-send the packet. The knowledge timeout period and the number of permitted re-tries are both user
programmable.
[ Do not use AKN mode with STAF repeaters. Timing conflicts occur ]
AKN mode provides the greatest data transfer reliability, although the overall data throughput is markedly
reduced.
Additional info on the M48 DIAG mode
Takes effect when returning to data mode (an EXIT or <escape> command)
The unit then does not output the received data burst.
Instead, it outputs a status line whenever ANY valid M48 packet is received
A:xx L:ll C:cc F:ff
Where,
xx
||
cc
ff
DIAG mode is deactivated by either re-entering setup mode and executing a NORM command, or by power-
on-reset
String commands
There are a series of special commands which allow whole strings of characters to be sent via the
transmitter, or the auxiliary serial port (usually connected to the radio module programming input)
Auxiliary port output operations
Square brackets (ASCII 91, 93) delineate the string. Serial data routed to the AUX pin
Command mode transmit operations
Radiometrix Ltd
COMMANDS
MEXT
AKN
TRIES rr
TIMEOUT tt
STAF
COMMANDS
NORM
PROM
DEFAULT
DIAG
[ (1-30 byte data string) ]
[ (1-30 byte data string) <cr>
$ (length byte) (1-16 byte data string)
destination address of the burst
checksum byte value
length of the burst data payload (minus one)
is a function byte, showing the status of the receiver decoder
(ff=07 indicates a correct address and checksum match)
FUNCTION
The unit returns to standard, transparent mode
Writes the current volatile settings (addresses and operating modes) into the E2PROM
as the new power-on settings
The unit self-reprograms with ALL original factory preset values
Enter a diagnostic mode, where the address, length, checksum and decoder status byte
for every received burst are printed
FUNCTION
Extended mode (burst ID on, multiple transmissions set by TRIES)
The unit now operates in aknowledge/resend (extended) mode
Number of transmissions attempts allowed in AKN and MEXT modes
Duration of AKN resend timeout (tt x 0.41mS)
Operate as a store and forward repeater (with MEXT set, or not)
( Note: $ is ASCII 36 )
Outputs the text string between the [ ] characters
As above, but with an added CR (13) appended to theend of
the outputted string
M48A Modem Data Sheet
page 7