3M Dynatel 945DSP User manual

78813034408-B Manual Instruction, 945DSP
Print this document 74% full size to fit in 945DSP carrying bag!
Overall size of document, with binding must not exceed 170mm high x 100mm wide.
Revision History
Rev 6 Released to art department
12/1/2000 Removed prior version screen image from page 13 and 17
12/12/2000 Page 5 – added reference to speaker disabled on low power
Released to Art Department
12/20/2000 Changed dbrn0P noise limits
Increased font size to 12pn
Rev 8 Resent to art department
Changed screen label graphics to permit pdf printing
Changed warning re effects of leakage current on opens P11
Added statement that escape key cancels P21
Changed shutdown beeps from 10 to 6 on P5
Rev B Version 2.15 Changes
2004/03/08 Removed Ohms to Distance, restored Soak

Dynatel 945DSP
Subscriber Loop Tester
Instruction Manual
March 8, 2004
78-8130-3440-8 Rev. B

FCC DECLARATION OF CONFORMITY
This device complies with Part 15 of the FCC
Rules. Operation is subject to the following two
conditions: (1) this device may not cause harmful
interference and (2) this device must accept any
interference received, including interference that
may cause undesired operation.
CE DECLARATION OF CONFORMITY
The EU Directives covered by this Declaration
CISPR 22:1998/EN 55022:1998 Radio Disturbance Characteristics for IT
Equipment
EN 300 386 V1.2.1 ( 1998-11) – EMC for Telecommunications Equipment
The Products Covered by this Declaration
3M Dynatel
¥ 945DSP Subscriber Loop Tester
The Basis on which Conformity is being Declared
The product identified above complies with the requirements of the above EU
Directives by meeting the following standards:
EN 6100-4-2 Electrostatic Discharge
EN 6100-4-3 Radiated RF Compatibilitity
The CE mark was first applied in: January 2001
The products described above comply with the essential requirements of the
directives specified.
ATTENTION!
The attention of the specifier, purchaser, installer, or user is drawn to
special measures and limitations to use which must be observed when the
product is taken into service to maintain compliance with the above
directives. Details of these special measures and limitations to use are
available on request, and are also contained in the product manuals

Table of Contents
POWER ON SCREEN ............................................ 6
VOLTAGE TEST .................................................... 7
LOOP CURRENT ................................................... 8
GROUND RESISTANCE ................................. 9
RINGERS COUNT.......................................... 10
RESISTANCE........................................................ 11
INSULATION SOAK...................................... 12
OPENS FAULT LOCATOR ................................ 13
OPENS SETUP ............................................... 14
SEND TONE ........................................................... 16
LOAD COIL COUNT ..................................... 17
DIALING................................................................ 18
AUTODIALER ................................................. 19
LOSS ....................................................................... 20
NOISE AND POWER INFLUENCE................... 21
LONGITUDINAL BALANCE ............................. 22
SELF CALIBRATION.......................................... 23
REGIONAL SETTINGS................................ 24
TYPICAL MEASUREMENTS ON A POTS LINE .... 25
WARRANTY................................................................... 26
INDEX TO SYMBOLS .................................................. 29

Page 1
New features for Version 2.15
The following new features were added to version 2.15
- load coil counter under the 6 ( tone ) key
- ringers counter under the 2 ( mA ) key
- in the autodialer phone number list, the ‘setup’ key can be
used to move backwards through the list
- when testing dead cable, LB is first under the dB key.
- added a backlite timeout. The backlite goes off after 1
minute of inactivity.
Out of the Box
What you will find when you unpack the shipping box:
• 3M ™ Dynatel ™ 945DSP
• Carrying case
• A set of four “AA” alkaline batteries
• Test Leads (red/black pair, and green)
• Instruction manual
• Quick Reference Card
For Technical Service, questions call: 800 426 8688 in the
US or Canada, or contact your local 3M Representative.
For Warranty, Repair or Ordering Information, please refer
to these sections near the end of this manual.
The Dynatel 945DSP comes with a carrying case and
should remain in the case to give extra protection from
shock and the environment. Install the unit in the case by
sliding it under the upper flap and securing it at the bottom
with the elastic strap. The leads are routed out through the
opening in the bottom of the case and may be stored in the
drop down pouch. Be sure to leave enough slack where
the leads enter the pouch to prevent pinching of the wires.
An additional pocket on the outside of the pouch is
provided for storage of the instruction manual.

Page 2
Batteries
A set of four “AA” alkaline batteries are provided. To
install them in the unit, loosen the two screws on the
battery cover and follow the placement diagram in the
bottom of the battery compartment. The unit will operate
for about 25 hours of continuous use ( no backlite ) on a
fresh set of alkaline batteries. You can also install ni-cad
rechargeable batteries that have been charged in a separate
user provided charger.
There is a battery gauge on the main power on screen. See
page 6 for information on this gauge. When the batteries
drop to 4V, an X appears on the gauge indicating you
should change your batteries as soon as possible. The unit
won’t operate when the batteries drop below 3.7V.
Don’t install used batteries in the unit. If one battery in the
pack is discharged more than the others, it will effect the
operation of the battery gauge and could cause the unit to
switch off without the normal low battery warnings.
Screen
The screen format is similar to the following for most
functions.
Graphical icons on the right of the screen indicate the
currently running test and any options that were set up for
the test. Below that is an icon indicating the function of
the setup key . This key is used in different ways for
different tests and the icon in the lower right of the screen
indicates its current function. Test results are displayed in
one or more boxes on the left area of the screen. Generally
a box with a dark bold border is displaying live readings
that change with conditions on the pair. Boxes with
Test Function
Test Options
Setup Key Function

Page 3
thinner borders indicate stored results. When more than
one result is shown on the screen, cycles between them.
The index at the end of this manual is a good way to
quickly find the meaning of any icon. Also, on the inside
pouch of the carrying case there is a card which provides an
easy reference to the most common of the graphical icons.
Test Leads
The Test Lead icons are shown on each of the measurement
screens. Each lead points to a colored dot on the front label
that corresponds to the actual test lead. The labels ,
and correspond to Ring, Ground and Tip for North
America and to B, Earth and A for other countries. All the
tests on the 945DSP use these same connections so there is
no need to rearrange leads between tests:
Red Lead to Ring or B
Green Lead to Ground or
Earth
Black Lead to Tip or A
Also, rearranging the leads or moving the leads to a new
pair while a test is in progress may cause inaccurate results.
You may need to return to the Power On Screen and restart
the test.
Keep the test leads clean and dry at all times to insure best
accuracy of the measurements. Use soap and water to clean
them if necessary.

Page 4
Keypad
The 945DSP Keypad has twenty keys. The twelve blue
keys are dual purpose. In some tests they function as
numeric keys, but most of the time they are used to select a
test.

Page 5
Control Keys
On/Reset/Off - Turns on the unit, or if it is already
on, resets to the power on screen. Press again to
switch off.
Adjusts the speaker volume.
Toggles the backlite on and off
Chooses an option or selects measurement mode
- T or R or G.
Changes the setup of the currently running test.
Undo an action or back up to make corrections
Adjusts contrast up
Adjusts contrast down
Test Keys
Voltage Measurements
Loop Current, Ground Resistance and Ringers
Resistance measurements
Self Calibration.
Opens Length Test
Transmit Tone and Load Counter
Dialing mode.
AC Tests – Loss, Noise, Power Influence and
Longitudinal Balance

Page 6
Power On Screen
Regional Settings - line frequency, units and auto
shut-off
This is the screen that you see when you first turn on the
945DSP. It shows the copyright year and the software
version. The battery symbol on the right gives an
indication of the approximate battery level. When the
voltage reaches 4.0 V, an X will appear on the symbol
telling you the batteries should be replaced. The speaker
is disabled to conserve power. Change your batteries as
soon as possible since the accuracy and operation of the
unit is not guaranteed. The unit shuts off when the battery
voltage reaches 3.7 Volts.
The unit has an auto shutoff timer. After 5 minutes with no
activity, the unit provides 6 quick warning beeps and shuts
itself off. When you hear the beeps, you can press to
prevent shut off. The auto shutoff timer can be disabled in
the regional settings described in the next paragraph.
When at the power on screen, you can press the key to
set regional settings such as ac power line frequency,
measurement units etc. See page Error! Bookmark not
defined.
From the power on screen you can run any test function.
Connect the leads as follows:
Red Lead to Ring or B
Green Lead to Ground or Earth
Black Lead to Tip or A

Page 7
Then press the desired test or control key.

Page 8
Voltage Test
or Selects T-R or R-G or T-G
Selects AC or DC measurements
This function measures the DC or AC voltage between the
test leads. The test begins by displaying the voltage from
the Red to Black lead in the center box. This box has a
thicker border than the others indicating that this reading is
‘live’ and will change as the voltage on the leads change.
Pressing moves the ‘live’ reading to one of the other
boxes showing the voltage from the Red to Ground lead or
Black to Ground lead. The boxes not currently ‘live’
retain their last measurement on the screen from memory.
Press the key to select between DC and AC volts. The
icon in the lower right area of the screen will change from
DC to AC. Press again to change back.
This symbol indicates that a high voltage has
been detected between the test leads. The
945DSP has opened an internal relay to protect
itself from damage. Use standard safety practices for
disconnecting the test leads since high voltage may be
present and press to reset the unit. In the volts test, this
warning appears if the voltage exceeds 350V. For most
other tests the limit is 75V. Tests that involve a working
circuit have a limit of 25V when in the offhook condition.
Tip – The key can be used as a shortcut for the key.
Press to enter the voltage test and then each subsequent
press of the key cycles to the next measurement.

Page 9
Loop Current
Runs the ground resistance test.
Runs a ringers count.
This function measures the DC current flowing through a
430 Ohm resistor inside the 945DSP. The test is run on a
working pair. Connect the Red and Black leads and press
to measure loop current.
After verifying correct loop current, you can press to
run the ground resistance check. Be sure red and black are
connected to a working pair and the green lead is connected
to ground. See the next page for more detail.
To count ringers, ensure the line is disconnected towards
the CO and connect to the pair going toward the subscriber.
Verify the loop current is 0mA and press to get a count.
This warning indicates the current is greater than
110mA. The 945DSP has opened an internal relay
to protect itself from damage. Use standard safety
practices for disconnecting the test leads. Press the key
to reset the unit and run the current measurement again.

Page 10
Ground Resistance
Reruns the ground resistance test.
You reach Ground Resistance from the mA screen. This
test measures the resistance of the ground between a
Central Office (C.O.) and the 945DSP by using an active
pair.
Ground Resistance must be done on a working POTS
circuit. Ensure the leads are connected to Ring and Tip (B
and A) with the Green lead connected to the ground to be
measured. Press the key to verify proper loop current,
then press to run the ground resistance test. The
945DSP displays the resistance from the end of the green
lead to the main ground at the central office.
The results on the screen are not ‘live’. You must press
to rerun the test and update the displayed result.
After completing the test, press to return to the loop
current screen or any other blue key to run another test.
This warning symbol indicates that the leads are
not connected properly or the circuit is not a
working POTS line. Reconnect the leads and
press to try again.
Note: The Ground Resistance function will only work on
pairs that are connected to C.O. switches with Tip (or “A”)
connected to ground. Pairs connected to “floating” switches
(such as the AT&T #5ESS) will not give correct results.

Page 11
Ringers Count
Count again.
Use this test to verify the connectivity into a subscriber’s
premise or to look for abandoned lines left bridged on.
First, disconnect the line towards the CO and connect the
clips to the pair going toward the subscriber. Press and
verify the loop current as 0mA ( the CO is disconnected ).
Now press to reach the ringers counter.
This function counts up to five ringers connected tip to ring
on a pair. A standard ringer is defined a 0.47uF of
capacitance. Electronic ringers may show as less than 1
ringer.
Press the key to repeat the count. When done, press
or any test key.

Page 12
Resistance
or Selects T-R or R-G or T-G
Runs the soak test.
This function measures the leakage resistance between the
test leads. The test begins by displaying the resistance
from the Red to Black lead in the center box. This box has
a thicker border than the others indicating that this reading
is ‘live’ and will change as the resistance between the leads
change. Pressing moves the ‘live’ reading to one of the
other boxes showing the resistance from the Red to Ground
lead or Black to Ground lead. The boxes not currently
‘live’ retain their last measurement on the screen from
memory.
The measurement method used on the 945DSP is able to
read resistance accurately even in the presence of foreign
voltage. After displaying an initial reading, the 945DSP
will check for foreign voltage and correct the reading if
necessary. A ‘V’ appears on the screen to indicate voltage
compensation is in effect.
Press the key to run the soak test. See the next section
for more detail.
Tip – The key can be used as a shortcut for the key.
Press to enter the resistance test and then each
subsequent press of the key cycles to the next
measurement.

Page 13
Insulation Soak
Selects R-G or T-G
Saves the reference reading
This function monitors the leakage resistance from the test
leads to ground and indicates changes in the insulation
resistance while it is stressed with a high voltage over time.
The test begins by displaying the insulation resistance of
the Red lead in the upper left box. This box has a thicker
border than the others indicating that this reading is ‘live’
and will change as the insulation resistance on the lead
changes. After the initial reading has become stable, the
945DSP stores it in the right hand box. Now observe the
reading as it changes over time. Pressing moves the
‘live’ reading to the lower box showing the insulation
resistance of the black lead. The key is used to update
the initial reading.
The way the insulation resistance changes over time gives
you an indication of the nature of the problem. Wet cable
faults tend to dry out when tested. The final value will be
higher than the initial saved value. Oxidation tends to
breakdown and become conductive over time which is
indicated by a reduction in resistance from the initial value.
Since you may want to run soak for some time, the
automatic shut off timer is extended to 30 minutes during
the soak test.
Note that voltage compensation is not used during the
insulation soak test. Foreign voltage on the pair will affect
the accuracy of the insulation soak measurement.
After completing the test, press to return to the
resistance screen or any other blue key to run another test.

Page 14
Opens Fault Locator
or Selects T-R or R-G or T-G
Setup capacitance factors
The opens function can be used to determine the distance to
both a “full” open as well as to a “partial” open. There are
three measurements provided – mutual length, tip length
and ring length. For a “full” open ( ie tip and ring are open
at the same place ) use the mutual reading. For a “tip”
open, use the tip length and for a “ring” open, use the ring
length.
The test begins by displaying the mutual in the center box.
Pressing moves the ‘live’ reading to one of the other
boxes showing the ring length in the upper left box or the
tip length in the lower left box. The boxes not currently
‘live’ retain their last measurement on the screen from
memory.
Leakage on the pair effects the accuracy of the length
reading. For pairs under 1km (3000') in length, the
945DSP will tolerate 20K ohm of leakage resistance and
will measure to a ‘dirty open’ with as much as 20K of
series resistance. For longer pairs, leakage should not
exceed 200K. Do not measure distance through a load coil.
When the unit displays ---- in the result box, there is a fault
on the pair that prevents the 945DSP from making a
measurement.
Ring Length
Tip Length
Mutual

Page 15
Note: The tip-ground and ring-ground measurements
require that the green lead be connected to a good ground.
All of these measurements depend on the 945DSP knowing
the capacitance per length of cable. Press to enter this
value for the cable type in use. See the next section for
more details.
Opens Setup
Selects T-R value or T-G value
Use blue keys to enter new values
Save new values and exit setup
Correct errors/ undo changes
Opens length is based on the capacitance of the cable pair.
For accurate results, the 945DSP needs to know the amount
of capacitance in a mile ( or kilometer ) of cable. There are
two separate values – one for the mutual capacitance and
one for the capacitance to ground. Exact values are
available from the cable manufacturer, but for convenience,
a table of typical values is provided below.
This screen starts out with the cursor in the box for the
ground capacitance value. Use the blue numeric keys to
enter the new value. Press to move to the mutual box
and again, key in the new value. When you are done press
to return to the opens measurement screen. If you
make a mistake you can press to back up and make
corrections. If you have selected metric mode in regional
Ground Capacitance
Mutual Capacitance

Page 16
settings the capacitance factors should be entered in nF/km,
otherwise use uF/mile.
Here are the factors for several typical cable types:
uF/Mile nF / Km
Groun
d
Mutu
al
Groun
d
Mutu
al
Aircore 0.125 0.083 77.7 51.6
Jelly
Filled
0.140 0.083 87.0 51.6
2 Pair
Drop
0.155 0.083 96.1 51.6
5 Pair
Drop
0.155 0.083 96.1 51.6
Tip: This chart is printed on the back of the quick
reference card in the plastic pouch of your carrying bag.