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.