BRUEL & KJAER 2236 Installation and operating instructions

Sound Level Meters are often used for
monitoring in remote places, and you
may want to “monitor the monitor” or
transfer measured data to your home-
base PC, without going to the measure-
ment site. A telephone connection —
wired or wireless — is a convenient way
to transfer measurement data. And mo-
dems are a vital link in the chain of trans-
mission. This application note explains
what equipment you need and how to
use it.
Please note that only Brüel&Kjær Types
2236 and 2260 are supported for modem
connection. Types 2231, 2237 and 4436
need special handshaking modes, which
cannot be activated via modem.
APPLICATION NOTE
Using Modems with Sound Level Meters

2
Using Modems with Sound Level Meters
2260 Semi-permanent Monitoring Kit
A sound level meter for monitoring in the field needs protection against
weather and tampering, and it needs a power supply other than its
internal batteries. Also, you need space and power for the modem.
For the Investigator Sound Level Analyzer Type 2260, the 2260 Semi-
permanent Monitoring Kit is available. It includes a weatherproof case,
12V battery, battery charger, cables, Outdoor Microphone Kit and soft-
ware for Type 2260 and for the PC. The case has room for all the
equipment including a modem, and it has a cable entry for feeding
external power to the system. A complete system including the 2260 is
also available: the 2260 Semi-permanent Monitoring System has all the
equipment in the Kit, plus the 2260, a calibrator, a tripod and an inter-
face cable for a PC. For ordering information, see the “Noise Monitoring”
System Summary sheet (BU3063).
Fig.1 2260 Semi-permanent Monitoring
System

3
Standard Modems
This section shows how to capture sound measurements from a remote
Sound Level Analyzer (Investigator Type 2260) via telephone lines and
standard modems. Precision Integrating Sound Level Meter Type 2236
may also be used.
The field equipment is illustrated in Fig.2.
Fig.2 Field equipment shown with
standard modem. The telephone line
connector is shown in the lid

4
Fig.3 Standard modem set-up
Fig.4 shows the complete system including the home-base modem.
Fig.4 System diagram. The diagram
does not include the optional DAT re-
corder
Standard Modems — Field Modem
The modem used in the field must be intelligent enough to provide
error correction, but dumb enough not to interpret any of the commu-
nication nor to add anything by sending messages to the sound level
meter (see APPENDIX 1: Selection of Field Modem).
Testing a number of modems, Brüel&Kjær has found the Multitech
MT2834ZDX to be the best choice, and recommends only that for field
use.
Brüel&Kjær does not provide technical support for other modems.
PC running
Evaluator
Type 7820
Hayes ¤ Compatible
Modem
Dumb Auto
Answer Modem
(Multitech MT 2834ZDX)
B&K 2236
or 2260
980001e
Brüel&Kjær Type2260
0
?
dB
Microphone Extension Cable
AO 0441 (3m)
AO 0442 (10m)
Sound Level Analyzer
Type 2260
+–
Outdoor Microphone Kit UA 1404
(Preamplifier ZG 0026 and
Microphone 4189, from 2260)
12V Battery
QB 0051
Panasonic
dflkfpojmmljflkjgjrg
grmowjgfpktjpw
Lightweight
Tripod
UA 0801
Tripod
UA 0587
Sound Level
Calibrator 4231
Mains Power Supply
ZG 0386 (EU)
ZG 0387 (UK)
ZG 0388 (US)
Mains Adaptor
(included with
Multitech Modem)
Mains Power
Evaluator 7820
Community noise
calculations Notebook/PC
TOSHIBA
Battery Charger
ZG 0404
MT2834ZDX
Field modem
Multitech
Home-base Modem
Hayes ®compatible Telephone
system
Case Type 3592
970551e
Cable for
12V Supply

5
Setting up the Field Modem
The Multitech modem is configured from the factory to be used as a
Hayes®compatible modem together with your PC. In order to get this
modem to work in the field you must do some programming of the
modem.
Begin by connecting the Multitech modem to COM1 or COM2 on your
PC, then start the Evaluator application. Choose Options… on the Tools
menu. Next select the Modem tab. On the modem droplist select User
Defined Modem, then set the actual COM-port where you have connected
the Multitech modem. Finally set the Baud Rate to 19200.
Table1 Equipment Equipment Type Available From
PC operating system Windows95®,
WindowsNT4.0®,
Windows®3.10 or 3.11
PC supplier
PC-modem cable Depends on modem and PC Modem or PC
supplier
Home-base modem Hayes® compatible
e.g. Multitech MT2834ZDX Modem supplier or Brüel&Kjær
(ZM0069)
Field modem Multitech MT2834ZDX Modem supplier or
Brüel&Kjær
(ZM0069)
Modem power Mains adaptor (supplied) or
9VDC Brüel&Kjær
SLM-modem cable AO0567 Brüel&Kjær
SLM 2260 (or 2236) Brüel&Kjær
SLM power 12VDC from QB0051 or
Mains Power Supply
ZG0386 (EU)
ZG0387 (UK)
ZG0388 (US)
Brüel&Kjær
2260 Semi-
permanent
Monitoring Kit
BZ7202–302 (English)
BZ7202–303 (French)
BZ7202–304 (German)
BZ7202 Enhanced Sound
Analysis SW
3592 Outdoor Gear
UA1404 Outdoor Microphone
Kit
AO0441 Microphone
Extension Cable (3m)
QB0051 12V Battery
AQ1698 Cable for 12V Supply
ZG0404 Battery Charger
AQ1700 Cable for DAT Remote
AO0543 DAT Signal Cable
7820–002 Evaluator (English)
7820– 003 Evaluator (French)
7820– 004 Evaluator (German)
Brüel&Kjær
Lightweight Tripod
Tripod UA0801 UA0587 Brüel&Kjær
Sound Level
Calibrator 4231 Brüel&Kjær

6
Click on the Test the connection… button to launch the Serial Commu-
nications Tool.
If your modem is properly connected to the PC, all the status indicators
except DCD should show ✓. To verify that the modem is recognized
enter the letters A and T in the String to be transmitted box and click
on the Enter button. The modem should then reply OK.
If your modem has reacted as described above, you can go on with the
programming of the modem. Enter the commands one bye one from
Table2 into the String to be transmitted box and click on the Enter
button after each command:
All 0characters on the list are zeros. Please note that this list of com-
mands is only valid for the Multitech modem. It is not guaranteed to
work with other types of modems.
Now the Multitech modem can be connected to the SLM in the field.
Use cable AO0567 which is a straightforward extension cable (male/

7
female 25-pin/9-pin cable with all lines in 1–1 connection) — Do not use
the Brüel&Kjær AO1386 cable in this case!
Setting up the 2236 for Modem Transfer
1. Press the <Show> button 9 times until the display shows INTERFACE.
2. Press the <Edit> button.
3. Press the or <Parameter> button until the display shows
19200 Baud.
4. Press the or <Level> button.
5. Press the or <Parameter> button until the display shows
Hardwire.
6. Press the <OK> button twice.
Now your 2236 has the right communication set-up and you can con-
tinue to set up the measuring parameters. As the Evaluator can only
remote control 2236 to start and stop measurements via the Autolog to
log command, you must start the initial log by specifying the sampling
interval, for example, Autolog to log every 1 min.
Setting up the 2260 for Modem Transfer
1. Press the button to enter the Setup screen.
2. Press the <Setup Menu> softkey.
3. Use the ❒soft key to move down and select PC communication.
4. Set the baud rate to 19200.
5. Press <Save>.
After having programmed the communication parameters you must se-
lect the desired measurement set-up. Please refer to your 2260 User
Manual for information.
Standard Modems — Home-base Modem
Most modems available for use with a PC will do well for the home-
base modem. It must fulfil the following requirements:
❍It must be Hayes compatible (supporting the AT command set)
❍The DCD (Data Carrier Detect) line must indicate the actual connec-
tion state
❍The modem must disconnect whenever the DTR (Data Terminal
Ready) line goes false
❍The modem must provide correction of transmission errors
Table2 CommandsfortheMultitech
modem Enter command Significance
ATM0 Speaker off
ATE0 No Echo
AT%E0 No Escape Sequence
ATS0=1 Answer incoming calls after first ring
AT$SB19200 Lock the baud rate to the SLM to
19200 bits/sec
ATQ1 No Result codes
AT&W0 Write the new configuration to the
modem non volatile memory

8
Setting up the Home-base Modem
After connecting the modem to your PC using the modem-PC cable, you
can configure the PC software. If you use Windows95 or
WindowsNT4.0, you must install the modem via the control panel in
Windows first.
Start the Evaluator Type 7820. Choose Options… on the Tools menu.
Next select the Modem tab. Again if you use Windows 95 or NT4.0, your
modem is already known by the system, so all you have to do is select
it on the drop-down list.
If you want to test the connection to the modem, you can click on the
Test the connection… button, whereby you launch the Serial Communi-
cations Debugging Tool. On this screen you can test the modem connec-
tion by selecting the Test Modem in the Function box in the lower right
corner.
If you use Windows3.10 or 3.11 or if you have problems getting your
modem to work under Windows95/NT4.0 you should create a User
defined modem set-up in Evaluator:

9
Select the COM-port and Baud Rate. In the INIT command and in the
DIAL command you can insert any string that the software should send
to the modem during initialization and dialing. Start by putting ATZ in
the init command and ATDT in the dial command. If more than one
command is needed for initialization just put <cr> (4 letters) in as
separator, for example:
AT<cr>ATZ<cr>ATM0<cr>
Please consult your modem manual for details on the command param-
eters.
Setting up the Telephone Numbers for Dial-up Sites
Evaluator has a built-in database for keeping phone numbers for remote
sound level meters, that will be contacted by the modem connection.
This database can contain any number of sites.
To define new Dial-up Sites, Choose Options… on the Tools menu. Next
select the Dial-up Sites tab. Then click on the New Site… button. Enter
the name of the new site — any characters except \ are allowed in the
site name.
Then enter the telephone number. The Dial prefix box can be used to
add extra dialing parameters, for example, to get a line outside a local
phone system. If your system requires that you dial, for example, a 0
to get an outside line, then put 0 in the dial prefix box, otherwise leave
this box blank.
Continue this process until all sites have been defined in the database.
Dialling a Remote Site
When your field system has been set up and your home-base modem
has been connected to your PC, you can start downloading measure-
ment data from the field.
This is done the same way that you would capture data from a SLM in
direct connection with a PC, except that you put a ✓in the box called
Connect via modem (Dial-up). When the ✓is set in the box, the screen
will change and you will be asked to choose which remote site to dial.

10
Once the PC has connection to the remote site, the rest of the download
process is the same as if the SLM was connected to your PC via the
AO1386 cable.
Wireless Modem
Using a GSM dataphone, your field system becomes truly mobile and
wireless — no power line and no phone line is required. There is an
extra team player in the communication chain: the GSM network oper-
ator. But once you have got the settings right, it works as smoothly as
the data transfer via normal telephone lines.
This section shows how to capture sound measurements from a remote
sound level analyzer (Investigator Type 2260) via GSM transmission in
the field and standard telephone lines and modems at the home-base.
(Precision Integrating Sound Level Meter Type 2236 may also be used).
The field equipment is illustrated in Fig.5.
Fig.5 Field equipment shown with wire-
less modem. The antenna must be
placed to the right in the foam insert,
before the lid is closed
Field Equipment
Fig.6 shows the complete system including the home-base modem.

11
Fig.6 System diagram. The diagram
does not include the optional DAT
recorder
Fig.7 Wireless modem set-up
2260 Semi-permanent Monitoring Kit
Please refer to the description in the Standard Modem section.
Brel& Kj r Type2260
0
?
dB
Microphone Extension Cable
AO 0441 (3m)
AO 0442 (10m)
Sound Level Analyzer
Type 2260
Field Modem
Siemens M1
+—
Outdoor Microphone Kit UA 1404
(Preamplifier ZG 0026 and
Microphone 4189, from 2260)
12V Battery
QB 0051
Panasonic
dflkfpojmmljflkjgjrg
grmowjgfpktjpw
Lightweight
Tripod
UA 0801
Tripod
UA 0587
Sound Level
Calibrator 4231
Evaluator 7820
Community noise
calculations Notebook/PC
TOSHIBA
Battery Charger
ZG 0404
Modem Hand-
switch ZH 0457
Home-base Modem
Hayes ¤compatible Telephone
system GSM network
Case Type 3592
970556e
Cable for
12V Supply
GSM
Antenna
SIM
Card
HandswitchZH 0631
Off
On
Brel BK
7/6-’89
&Kjr
Enhanced Sound
Analysis Software
BZ 7202
FLASHDISK
5
MB
MAGSSTORAGE
SYSTEM
Sun isk
970560e
PC running
Evaluator
Type 7820
Hayes ® Compatible
Modem
Modem at
GSM Operator
GSM Net
Operator
Brüel & Kjær 2236
or 2260
Siemens Mobile
Dataphone M1

12
Table3 Equipment Equipment Type Available From
PC operating system Windows95
WindowsNT4.0
Windows3.10 or 3.11
PC supplier
PC-modem cable Depends on modem and PC Modem or PC
supplier
Home-base modem Hayes compatible
e.g. Multitech MT2834ZDX Modem supplier or Brüel&Kjær
(ZM0069)
Field modem Siemens Mobile Dataphone
M1 Siemens supplier
GSM SIM Card For non-transparent data
transfer Network operator
Modem Handswitch ZH0457 Brüel&Kjær
Antenna + mounting See section “Antenna” below Mobile-phone
supplier
SLM-Modem cable AO1440 Brüel&Kjær
SLM 2260 (or 2236) Brüel&Kjær
2260 Semi-permanent
Monitoring Kit BZ7202–302 (English) BZ7202–303 (French)
BZ7202–304 (German)
BZ7202 Enhanced Sound
Analysis SW
3592 Outdoor Gear
UA1404 Outdoor Microphone
Kit
AO0441 Microphone
Extension Cable (3m)
QB0051 12V Battery
AQ1698 Cable for 12V Supply
ZG0404 Battery Charger
AQ1700 Cable for DAT
Remote
AO0543 DAT Signal Cable
7820– 002 Evaluator (English)
7820 – 003 Evaluator (French)
7820 –004 Evaluator (German)
Brüel&Kjær
Lightweight Tripod
Tripod UA0801 UA0587 Brüel&Kjær
Sound Level Calibrator 4231 Brüel&Kjær

13
Wireless Modems — Siemens M1 Mobile Dataphone
Fig.8 Siemens M1 Mobile Dataphone At the field end we need a device
which is a combination of a mo-
bile phone and a modem. A suit-
able device is the Siemens M1 —
it runs on 12V external DC supply,
and it has a 9–pin RS–232 inter-
face to the built-in modem which
“talks” directly to the built-in GSM
phone unit. It includes a split ca-
ble for power supply and antenna
connection.
Currently the maximum transfer
rate of this system is 9600 bits/
sec set by the network operator.
In the future the transfer rate may
increase to 19200 bits/sec (which
the M1 is designed for).
Setting up the GSM System
SIM Card
First of all you must have a GSM SIM card in order to get access to the
GSM network. Make sure that this SIM card is set up to work with NON-
TRANSPARENT DATA TRANSFER by your network operator. Note that
the phone number for data transfer may not be the same as the phone
number normally used with this SIM card. Secondly the SIM card must
not require that a PIN code be entered before use.
Siemens M1
When ordering the Siemens M1, make sure it supports NON-TRANSPAR-
ENT data transfer. This means that the M1 firmware must be version
4.02 or later. See APPENDIX 2: Software Update for Siemens M1, for
details.
Next the M1 should be programmed for autoanswer mode. To do this
connect it to your PC on COM-1 or COM-2 and start the Evaluator
software. Choose Options… from the Tools menu. Then select the Modem
tab.
From the modem droplist select User Defined Modem. Set the actual
COM-port where you have connected the M1. Finally set the Baud Rate
to 9600.
Table4 Siemens M1 Mobile Data-
phone – manufacturer’s specifica-
tions
Type M1 Nominal voltage 13.2V
Housing Plastic Input current Max. 500mA
Dimensions 116 x67x30mm Class of
protection III
Weight 157g Temperature,
operating –20 to +55°C
Memory Flash EPROM Temperature,
storage –40 to +70°C
Input voltage +8 to +24V Antenna
impedance 50Ω

14
Then click on the Test the connection… button.
By entering AT and clicking on the Enter button the M1 should answer
OK.
The command AT+CSQ indicates the signal quality (a number between
0 and 31, where 31 is the best).
The command AT+COPS? shows whether you have been registered on
the network or not. It should reply with the name of your network
operator.
Now the M1 should be programmed to be in auto-answer mode with a
non-transparent error correction protocol and the result codes should
be disabled.
Enter the commands from Table5 , one by one.
After finishing programming you will notice that the M1 no longer indi-
cates OK to every command, that is because the ATQ1 command has
disabled the output of the results codes. Result codes must be disabled,
otherwise 2260 will try to interpret these messages.

15
If you the enter AT\S you should get this status screen:
Now you can switch off the M1, position it on the remote site and
connect it to the SLM with an AO1440 cable (which is a male/female
9-pin/9-pin RS–232 cable).
Table5 Siemens M1 programming
commands Enter Command Significance
ATS0=1 Answer after 1st ring
AT\N6 Operating mode: Non-Transparent,
with RLP protocol
ATB98 Operating mode: Autobauding
Modem, 9600 Baud
ATQ1 No Result codes
AT&Y0 Load User Profile 0 at power-up
AT&W0 Write the new configuration to non-
volatile memory as User Profile 0

16
Wireless Modems — Modem Hand-switch ZH0457
The Modem Hand-switch ZH0457 serves to supply power from the 12V
Battery QB0051 to the Siemens M1 Mobile Dataphone.
Fig.9 Modem Hand-switch ZH0457
The M1 is supplied with a split cable for supply from 12V power (and
for the antenna). The power supply cable ends in three wires: a red
(+12V), a brown (0V) and a violet (called “ignition”).
The Modem Hand-switch ZH0457 provides a connector for the 12V and
a means of switchingthe “ignition” since this must be done in the proper
sequence for the M1 to work.
Connecting the M1 to the ZH0457
1. Open the ZH0457 by removing the four screws at the bottom.
2. Take out the rubber seal and the nylon strap lying inside the ZH0457.
3. Feed the M1 power cable (with the 3 wires) through the rubber seal
(pull the thick end through first).
4. Put the 3 wires through the hole in the ZH0457 base.
5. Screw the red wire into the connector block opposite the red wire
already connected.
6. Screw the violet wire into the connector block opposite the violet
wire already connected.
7. Screw the brown wire into the connector block opposite the brown
wire already connected.
8. Put the rubber seal (and the cable) through the hole in the ZH0457
base.
9. Fasten the rubber seal and cable by mounting and tightening the
nylon strap.
10.Reassemble the ZH0457 and fasten the four screws.
Connecting the Power Supply to the M1:
The 12V battery QB0051 must be in charged condition and equipped
with the 12V Cable AQ1698.
1. Connect the ZH0457 to the socket on the AQ1698.
2. Make sure that the switch on the ZH0457 is in the Off position.
3. Connect the M1 cable to the M1 Mobile Dataphone.
4. Press the switch on the ZH0457 to select the On position — the light
in the switch should turn on.
5. The M1 is now powered from the 12V battery.
6. To remove power from the M1, press the key on the ZH0457 to select
the Off position.

17
7. Wait until the green power indicator on the M1 stops flashing (it may
take up to 10s).
8. Now the M1 cable or the 12V connection may be disconnected.
Warning: The above sequence should always be followed, otherwise
damage may result to the M1 or the SIM card.
Battery Life
The M1 will typically consume 70mA when in the standby mode (which
it will be most of the time). During transmission the consumption in-
creases as indicated in the table below.
Assuming consumption of 70mA and the recommended set-up for the
2260, batttery life for the QB0051 will be reduced by about 20%, corre-
sponding to one day.
Antenna
The Siemens M1 Mobile Dataphone must be connected to a suitable
antenna of 50Ωimpedance. Since transmission conditions vary greatly,
it is not possible to predict the field performance of a particular antenna
design or placement. In many cases a simple antenna (the type used in
cars) is sufficient, and the non-conducting case offers some interesting
mounting features. There are generally two types of simple car antennas:
one for mounting on metal (for example on the roof) and one for mount-
ing on glass (for example a windscreen).
The type for mounting on metal (also known as a ground plane) may be
placed in the foam insert at the position normally occupied by the
tripod. Take care not to place other conductors (cables) close to the
antenna. The non-conducting case allows transmission of the GSM sig-
nal. If required, transmission can be improved by placing a ground plane
(conducting metal sheet, at least 50×50cm) under this antenna.
The type for mounting on glass has two self-adhesive units to be fastened
precisely opposite each other on each side of the window (case lid for
our application). The antenna itself is clicked into the outer unit and
can be removed for transport. Fig.10 may help in locating the two units
precisely.
Antennas designed for use in boats are available and may provide better
transmission. They do not need a ground plane.
Checking Transmission in the Field
To check transmission in the field, use a normal mobile phone and call
up the M1 (which must be connected to the 2260 and both devices
turned on). Check that the call comes through. If not, and antenna
problems are suspected, try one or a combination of the following:
❍re-orientate the antenna
❍move the antenna to a higher position
❍provide a ground plane for the antenna
Table6 M1 Power Consumption at
12V – manufacturer’s data Channel
Search Standby Send Mode
Typical Max. Typical Max.
130mA 70mA 150mA 220mA 500mA

18
Fig.10 Template for positioning the
parts for a car antenna (glass-mounting
type) on the inside and outside of the
case
The Home-base Modem
The home-base modem should be set up as described in the Standard
Modems — Home-base Modem section.
The SLM
The 2236 or the 2260 should be set up as as described in the Setting
up the 2236 for Modem Transfer and Setting up the 2260 for Modem
Transfer sections, except that the baud rate must be set to 9600.
APPENDIX 1: Selection of Field Modem
The modem used in the field is critical, because it must be intelligent
enough to provide error correction, but dumb enough not to interpret
any of the communication nor to add anything by sending messages
such as »CONNECT« to the sound level meter.
The requirements for the field modem can be summed up as follows:
❍Error correction must be supported
❍The baud rate towards the SLM must be fixed without any relation
to the baudrate used on the phoneline
❍Hardwire handshake (RTS/CTS) must be supported
❍The modem must not interpret any commands
❍The modem must not send any status messages to the SLM
❍The DCD line must indicate the actual connection state
❍The modem must disconnect when the carrier signal disappears
❍The modem must be able to work over an extended temperature
range
Testing a number of modems in the field, Brüel&Kjær has found the
Multitech MT2834ZDX modem to be the best choice, and recommends
that only this modem is used for field use. Brüel&Kjær does not provide
technical support for any other modem.
Case lid,
internal view
105 mm
95 mm
External brace
Antenna
cable
970559e

19
APPENDIX 2: Software Update for Siemens M1
When ordering the Siemens M1, make sure it supports NON-TRANSPAR-
ENT data transfer. This means that the M1 firmware must be version
4.02 or later. If not, you can get it from Siemens. Also you can get a
description of the new software features (Word file M1-nt2.doc) from
Siemens.
The Siemens instructions to download the new software are the follow-
ing:
Downloading New Software
The M1 consists of two hardware parts, the DSA (Data Service Adapter)
and the Mobile. Because of this the software update consists of two files:
1. DL_0_50N.EXE — software update for the DSA (test version)
2. M1_4_02N.EXE — software update for the Mobile
To update the M1 be sure that it is switched on, and that the M1 is
connected with the COM port of the PC. Then execute the two files in
the order mentioned above:
1. If the M1 is connected via the COM2 port enter: DL_0_50N -COM2
to implement the new DSA software.
For help enter: DL_0_50N -H
2. To implement the new M1 software, enter: M1_4_02N -COM2
Note: The current version of the User Guide and of the M1 software
can be found in the following mailbox:
Mailbox telephone number: [phone].

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