Aeroflex 2945B Quick Start Manual Download Page 4

Before you make a call, you should set up the identity of the test

set and of the radio you want to call, to avoid calling anyone else

on the system.  The test set has default values for group and log-

ical identities of 1.

The radio parameters set-up screen.

Press the [SET-UP] soft key until the screen above appears. The

radio logical ID is the identity of the radio the test set will call. The

IFR ID is the identity that the test set will use when it makes or

responds to calls. The group identity is both the group that the test

set will call, and the group identity that it will respond to.

If you now go back to the Manual test screen, and select [mode],

[individ call] the test set will attempt to make a call to the radio

whose identity is in the RADIO LOGICAL ID field. The mode

should change to WC CONFIRMATION, and then to WORKING

CHANNEL.

The MANUAL TEST screen after a successful individual call.

Selecting [mode], [clear down] will return the test set to the con-

trol channel.

You should now have a working EDACS repeater test system,

ready to go!  The system parameters are stored internally in non-

volatile memory, but you may also like to take this opportunity to

save the settings on to a PCMCIA memory card.

Measuring off-air

The IFR 2945B test set has several tests built in to allow monitor-

ing and diagnosis of EDACS repeaters.  These are designed to be

used off-air, and on a live system, so that the condition of the

repeater can be continuously monitored, without disrupting the

system traffic, as well as being connected physically to the

repeater RF and audio connections.

Distortion measurements can be performed on a channel with-

out requiring audio access to that channel.  Three different dis-

tortion measurements are available - SINAD, signal to noise and

distortion, which should not be used in isolation. The values

returned by these tests should be used to detect degradation in

performance, with relative results being important, and not the

absolute values. 

Data deviation tests are provided for both low and high speed

data, with the tests using advanced DSP (Digital Signal Processor)

filtering.

A data performance test is also provided, to allow the receiver on

the control channel to be tested.

All of these tests have test limits and parameters stored in mem-

ory so that you can tailor the test and the limits to your particular

system. The parameters are set up using the AUTORUN PARA-

METERS screen.

Additionally, one of the built in test programs, the QUICK TEST, is

designed specifically for use off-air.  

The AUTORUN PARAMETERS set-up screen.

As an example, in order to set up the Quick test, we need to alter

the RF generator levels for all the signalling tests, and set the data

deviations to those in use on the system.

1) Set the RF GEN LEVEL to be +5 dBm for the: 

CALL FROM IFR,

CLEAR FROM IFR and

DATA PERFORMANCE tests.

2) To do this, use either the up and down arrow keys, or the rotary

control.

3) Highlight the test required (the DATA PERFORMANCE test in

this example).

4) Now press [select] and a list of the test’s parameters is given.

5) Select the RF GEN LEVEL entry, and press 5.

6) 

Then press either the [dBm] softkey, or the orange

[dBm/ENTER].

7) Pressing [return] returns you to the list of tests.

You should also set up the data deviations initially with either a

generous error tolerance (say 30%) or the known correct values

for your system.

Finally, the Tx LEVEL test is of little use in off-air measurement, and

should be turned off.  The problem is caused mainly by the vari-

ability of the environment around the antenna (people, vehicles,

and buildings appearing between the antenna and the repeater),

Summary of Contents for 2945B

Page 1: ... Monitor is ideal ly suited to the testing of trunking repeaters It provides an extensive array of tests allowing verification of per formance and rapid diagnosis of faults This application note will assist the first time users by lead ing them through the initial stages in setting up the 2945B and testing an EDACS repeater The majority of this document is concerned with using the 2945B test set o...

Page 2: ...rom the radio The frequency plan can be examined and then entered into the test set Next you need to know the data rate EDACS can operate at two different data rates 9600 baud or bits per second with a chan nel spacing of 25 kHz per channel or 4800 baud with channel spacing of 12 5 kHz As a general rule if the frequencies in the frequency plan are in the 900 MHz band then the data rate will be 480...

Page 3: ...to be picked up by the test set or the frequency plan is incorrect To check the data rate you should turn the sound volume up on the front panel and then step through the channels using the control channel key When you hear a continuous drone select Tx TEST and press Scope Bar until the large scope display appears Press the Persistence key until High is highlighted when you should see an eye diagr...

Page 4: ...is tortion measurements are available SINAD signal to noise and distortion which should not be used in isolation The values returned by these tests should be used to detect degradation in performance with relative results being important and not the absolute values Data deviation tests are provided for both low and high speed data with the tests using advanced DSP Digital Signal Processor filterin...

Page 5: ... for pass 0 for fail ctrl D Put the test set back to local mode Data Displays and Decode Only Since the data displays and decode only facilities may not be available for all systems the IFR 2945B product is normally sup plied with this functionality disabled Forfurtherinformation please contact the Aeroflex help desk 1 800 835 2350 Data Display The purpose of this screen is to show the data frames...

Page 6: ...erial transfer parameters both in the ter minal program and also on the test set On the test set the seri al configuration is changed using the serial setup screen press HELP SETUP Setup Setup Page 2 Serial Setup Finally log the transfer on the computer to a file if you are using the Windows terminal program select Transfer ReceiveText File and enter the filename Summary The 2945B test set is an i...

Page 7: ...For the very latest specifications visit www aeroflex com ...

Page 8: ...14 0047 SPAIN Tel 34 91 640 11 34 Fax 34 91 640 06 40 UK Burnham Tel 44 0 1628 604455 Fax 44 0 1628 662017 UK Stevenage Tel 44 0 1438 742200 Fax 44 0 1438 727601 Freephone 0800 282388 USA Tel 1 316 522 4981 Fax 1 316 522 1360 Toll Free 800 835 2352 w w w a e r o f l e x c o m i n f o t e s t a e r o f l e x c o m As we are always seeking to improve our products the information in this document giv...

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