This section describes the design, function and operation of the Mobitex Base
Radio Unit 3 (BRU3).
During normal operation, all actions neces s ary for the operation and check of
the BRU3 are carried out at the Network Control Centre (NCC). When
operating the BRU3 on site, the following equipment is required:
•Portable PC including VT-100 emulation software.
•FE Console Cable TSRA 902 0190 for connection of the terminal to the
BRU3 connector "P1-CONSOLE".
For a description on how to connect the por tabl e PC to the BRU3, please refe r
to Shutdown Procedure in the Start-Up and Shutdown Procedures section
below.
BRU3 is a complete one-chann el compact radio base station which uses 8 kb ps
data signalling and is designed for the 400, 800 or 900 MHz band. The BRU3,
which may be installed both outdoors and indoors, is a link between the mobile
terminals (MOB) and the area exchanges (MOX) in the MOBITEX Network.
1.2Mec hanical Parts
The BRU3 consists of two main mechanical parts, the FE Case Bottom Frame
(FBF) and FE Case Top Frame (FTF).
The FBF is fixed on site. This part has weather-protected throughputs for the
cabling, the FE Connection Board (FNB), the FE Power Supply Unit (FPU) and
the FE Battery Unit (FBU) for power supply backup.
The other part, the FTF, is hinged to the bottom part and works as a cover and
cooling flange, offering good thermal management for the BRU3. The FTF
includes the FE Computer Board (FCB), the FE Modem Board (FMB), the FE
Radio Board (FRB), the FE Filter Module (FFM) and the FE Heating Unit
(FHU).
The BRU3 is lockable to prevent unauthorized access to the unit. To avoid
corrosion, the painted white mechanical parts are made of corrosion-resistant
material.
Pos 2 is used as the antenna connection when a combined RX/TX antenna is
used.
The table below gives a brief description of the BRU3 connections used. The
position numbers found in the “Position” column refer to the corresponding
position numbers in Figure 3.
Pos.Connector
3MAINS INLETIEC120/230V AC inpu t fro m t he BRU 3 site
1RX ANT.TNCSignals f r om the rece iving ante n na (RX).
2TX ANT.
ALT.
RX/TX ANT.
4P3-TELEPHONE9p d-subTelephone line connection.
5P5-RS422B25p d-subConnection to MOX via balanced serial
Type of
Connector
power supply.
TNCSignals to the tr ansmitti ng antenna T X.
Signals to/from th e co mb in ed RX/TX
antenna.
interface RS422B.
Connection To/From
6P4-RS232C25p d-subConnection to MOX via un-balanced
7P2-ALARM9p d-subConnection used for external alarm.
8P1-CONSOLE9p d-subConnection used for Console/ NODOP
Note!When startin g u p the BRU3 after installation, follow the
instructions under Hardware Commissioning Procedure and
Software Commissioning Procedure in the Commissioning
Procedure section of the BRU3 - General module.
1.3.1Start-Up Procedur e
When starting up the BRU3, do as follows:
1.Set the "MAINS SWITCH" located on the FE Po wer Supply Unit (FPU)
to positi on "1".
2.Set the "BATTERY SWITCH" located on the FPU to position "1".
3.Check that the yellow status LEDs are lit on the FE Co mputer Board
(FCB) and the FPU.
4.Check, after a few seconds, that no red alarm LEDs are lit on the FCB or
FPU.
Note!The warm-up time for the BRU3 is required to be at least 30
minutes, before the transmitter is activated. Specifications for the
BRU3 are valid after this period.
1.3.2Shutdown Procedure
To ensure minimal traffic and data loss when the power to the node has to be
shut down, always perform the following shutdown procedure:
1.Connect the portable PC via the FE Console Cable TSRA 902 0190 to the
port "P1-CONSOLE" on the FE Connection Board (FNB).
2.Press return to get the NODOP prompt NODOP>
Note!If the node has just s tar ted, it will take a little while before
NODOP is functioning.
3.Give the command HALT 120 on the NODOP terminal.
4.When you are asked to verify the command, enter Y.
5.The shutdown procedure will stop all incoming traffic and close all open
files. A message will be displayed on the console terminal when the node
may be switched off.
1.3.3Res tarting the BRU3 (Warm Start)
Restart (RESET) can be performed either of the entire node or of certain units.
•By command from an NCC operator.
•By the NODOP command BOOT using a terminal.
•Manually for different units.
•Automatically, by the software for the different units.
1.3.4Manual Restart of the BRU3
The manual restart procedure below should be used only if NODOP does not
respond to any command. Otherwise, use the NODOP BOOT command.
Pressing the reset button will cause an immediate restart of the BRU3, without
ensuring a proper node shutdown. The restart may result in loss of user traffic
and data.
The reset button (SW1) is located on the FE Computer Board (FCB).
After the restart, the BRU3 will be reinitiated, implying logical connection of
all serial communication.
This is short description on how to boot the BRU3 using a PC and a terminal
program. When the connection is up and running (use 19200 bps 8N1), cold
start the BRU3 by switch ing the power on and off. Afte r a short while, some text
will be displayed on the terminal.
Steps 1-7 below d escrib e ho w to do wnload so ftw are from t he PC to th e BRU3.
These steps are required only if no main software is present on the BRU3 disks.
To check if the main software is present on the disks, use the command “DI”.
Check if there is a “.mfe” (like the one stated in step 6) file on either of the disks
wp1:, wp2:, wp3:, etc. The name for the di sks (wp1, etc.) that are present can be
seen at the start-up.
Note!Do not forget the colon “:” after the disk name.
File names stated in the instruction are only examples of file na mes and sho uld
be replaced by correct names.
1.On request, enter !!! and set the thumb wheel in position 7 for the
command prompt (CMD>).
2.Type ASY at the CMD> prompt.
3.Send the config (config.bin) with the terminal program using zmodem.
4.When the download is finished, the BRU3 will reboot.
5.Get the BRU3 into software transfer mode again by following steps 1 and
2 (if you do not already have a CMD> prompt).
6.Send the main software (main_sw.mfe) with the terminal program using
zmodem.
7.When the download is finished, the BRU3 will reboot.
8.Get the BRU3 into software transfer mode again by following steps 1 and
2 (if you do not already have a CMD> prompt).
The choice between telephone modem, balanced serial interface and
unbalanced serial interface, is made via hardware strapping, i.e., only one line
interface alternative is available at a time. In some BRU3 variants the telephone
modem is not applicable which means th at only a balanced serial interface and
an unbalanced serial interface are available.
The hardware strapping is made by setting switch 2 (SW2) on the FE Computer
Board as follows:
Switch 2
SW2:1SW2:2SW2:3Comments
Open or ClosedOpenOpenV.32bis
OpenOpenClosedV.28 (RS232)
ClosedOpenClosedV.11 (RS422)
Other altern atives not allowed.
SW2:4Comments
OpenOEM-Strap
1.4.2Telephone Modem Boards
The telephone modem, whi ch supp orts th e CCITT V. 32 and V.3 2bis standa rds,
consists of two separate boar ds , the FE Modem Board V.32 (FMB) and the FE
Adaptation Board (FAB). Depending on national requirements issued by the
telecommunications administration in each country, different versions of the
FAB may be used. Also, the information regarding telephone modem in this
manual may not be applicable to all BRU3 variants.
Two-wire leased, four-wire leased or switched lines are used for data
transmission. The maximum transmission rate is 14 400 bits/sec. The modem is
connected to the computer part via a synchronous serial circuit.
Asynchronously transferred AT/Hayes commands are used for modem
configuration and check.
The FE Connection board ( FNB) includes conversio n circuits for V.1 1 and V.28
standards for the serial interfaces. It als o includes vo ltage pr otection and filters
for the modem, the V.11, the V.28 and the console ports.
The FNB contains the following connectors:
P19-pole D-SUB male, used for CONSOLE connection
P29-pole D-SUB female, used for alarm connections
P39-pole D-SUB female, used for connection of telephone lines
P4(RS232-MOX) 25-pole D-SU B male , used for modem connect ion.
P5(RS422-MOX) 25-pole D-SUB male used for modem connection.
The FE Computer Board incl udes two ports, A and B, for serial communication,
both handled by the integrated circuit Z16C35.
Network Connection (Port A)
Port A implies complete synchronous functionality, and also, limited modem
support. By the FNB and FMB, this port can be used for V.24/V.28, V.24/V.11
or V.24/V.32.
CONSOLE and NODOP Connection (Port B)
Port B is intended for using a CONSOLE and NODOP via the FNB with the
V.24 signals RX and TX.
Status indicatorYellowLit when the processor is operating OK.
Watchdog alarmRedLit when the Watchdog is released. If so, a
reset pulse is generated. The Watchdog LED is
lit and the signal WDSTATUS, read b y the
CPU, peaks.
1.5.4Reset Button
To enable hardware reset of the FCB and the FMB (Modem Board), and also,
the FRB (FE Radio Board), the FCB is equipped with a reset button located next
to the LED Status indicator. To reach the b utton for a reset op eration, us e a pen
or a similar object.
A reset of the FCB may be generated for the following reasons:
1.Power-on reset: The reset is generated at power-on, and also, when a
power drop occurs.
2.Switch reset: The reset is activated when the reset button is pressed.
3.Watchdog reset. The reset is activated by th e watchdo g function if not
maintained.
4.CPU reset: The reset is performed by the CPU when a reset instruction is
executed. In this specific case no reset of the CPU itself is carried out.