Test Report

FCC ID: PQMMSS1

Test Report

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FCCID_166641

Caterpillar, Inc. Page 1 of 40 EMC – Machine Security System (MSS)

Test Report No: 01-11-35005/499

Electromagnetic Compatibility
Of A
Machine Security System (MSS)
156-6155

EMC Testing, Inc Report - MSS.doc 07/17/01

Caterpillar, Inc. Page 3 of 40 EMC – Machine Security System (MSS)

Contents
1 Basic System Description ……………………………………………………………………… 4

2 Theory of Operation ……………………………………………………………………………... 4

3 Test Procedure and Equipment Used …………………………………………………………… 5

4 Configuration and Identification of Device Under Test ………………………………………. 7

5 Radiated Emission Limits ……………………………………………………………………….. 8

6 Radiated Emission Tests and Results …………………………………………………………. 11
Low Frequency Data
a. Baseline SAC (9 KHz to 30 MHz) ………………………………………………………. 11
b. Continuous RF at 0 degrees (9 KHz to 30 MHz) ………………………………………. 12
c. Continuous RF at 45 degrees (9 KHz to 30 MHz) ……………………………………… 13
d. Continuous RF at 90 degrees (9 KHz to 30 MHz) ……………………………………… 14
e. Continuous RF at 135 degrees (9 KHz to 30 MHz) …………………………………….. 15
f. Continuous RF at 180 degrees (9 KHz to 30 MHz) ……………………………………. 16
g. Continuous RF at 225 degrees (9 KHz to 30 MHz) ……………………………………. 17
h. Continuous RF at 270 degrees (9 KHz to 30 MHz) ……………………………………. 18
i. Continuous RF at 315 degrees (9 KHz to 30 MHz) ……………………………………. 19
j. Steady State at 0 degrees (9 KHz to 30 MHz) ………………………………………….. 20
k. Steady State at 45 degrees (9 KHz to 30 MHz) ………………………………………… 21
l. Steady State at 90 degrees (9 KHz to 30 MHz) ………………………………………… 22
m. Steady State at 135 degrees (9 KHz to 30 MHz) ……………………………………… 23
n. Steady State at 180 degrees (9 KHz to 30 MHz) ……………………………………… 24
o. Steady State at 225 degrees (9 KHz to 30 MHz) ……………………………………… 25
p. Steady State at 270 degrees (9 KHz to 30 MHz) ……………………………………… 26
q. Steady State at 315 degrees (9 KHz to 30 MHz) ……………………………………… 27
High Frequency Data
r. Baseline – Horizontal plane ……………………………………………………..………. 28
s. Steady State – Horizontal (30 MHz to 1 GHz) ………………………………….……… 29
t. Continuous RF – Horizontal (30 MHz to 1 GHz) ……………………………………… 30
u. Baseline – Vertical plane ………………………………….…………………….………. 31
v. Steady State –Vertical (30 MHz to 1 GHz) ……………………………………….……. 32
w. Continuous RF – Vertical (30 MHz to 1 GHz) ………………………………….…….. 33

7 Additional Measurements and Computations
a. Tabular representation of Continuous RF – Vertical (30 MHz to 1 GHz) ………….. 34
b. Expanded plot of Continuous RF – Vertical (30 MHz to 200 MHz) ………………… 35
c. Expanded plot of Continuous RF – Vertical (30 MHz to 100 MHz) ………………… 36
d. Tabular representation of Continuous RF – Vertical (30 MHz to 100 MHz) ……… 37
e. Continuous RF – Vertical (30 MHz to 100 MHz) – Coil Disconnected ……………… 38
f. Continuous RF – Vertical (30 MHz to 100 MHz) – Coil replaced by 50 ohm load … 39

8 Conclusions …………………………………………………………………………………….. 40

EMC Testing, Inc Report - MSS.doc 07/17/01

Caterpillar, Inc. Page 4 of 40 EMC – Machine Security System (MSS)

Basic System Description
The Caterpillar Machine Security System (MSS) reduces the potential for theft or unwanted operation
of a Caterpillar machine by disabling critical machine functions thereby not allowing the machine to be
started. Functionally it is very similar to automotive immobilizers which use RFID (Radio Frequency
ID) transponders embedded in the key to determine the authorization level of a machine operator.

The MSS system consists of an ECM (Electronic Control Module), a coil which energizes the RFID
transponder and also receives data from the transponder, an electronic key which includes an RFID
transponder, a Bi-Color LED which indicates system status to the operator, and two output drivers
used to provide 2 points for disabling the machine.

The exciter coil is mounted on the machine console such that it encircles the keylock. The Bi-Color
LED is also mounted on the machine console. The ECM is mounted in an inconspicuous location
separated from the coil by as much as 15 ft.

Theory of Operation
When an operator attempts to start a Caterpillar machine equipped with MSS he first activates the MSS
system and requests key authorization by turning the key to the “on” position. The coil is then
energized at a constant 134.2 KHz for approximately 50 ms. This energy is used to “charge up” the
transponder embedded in the electronic ignition key. Power is then removed from the coil and the
transponder transmits its ID and other relevant information to the ECM via the same coil for a period
of 20 ms. This cycle is repeated 3 times in succession to confirm integrity of the transmitted message.
The ECM then analyzes the authorization level of the key. If it is determined that the key is authorized
for use on that machine then power is provided to two output drivers which are wired by the individual
machines to enable critical functions (such as main power relay, starter motor, fuel shutoff solenoid,
etc.). Power for each of these driver functions is provided on separate input lines to the control
enabling logical control of these functions upstream of the MSS control.

An authorized key results in a green light from the Bi-Color LED. An unauthorized key produces a
red light. A faulted condition causes the LED to flash red.

Once the machine has been successfully started the MSS system continues to provide power to the 2
driver circuits but no further “read” attempts are made on the key (i.e. the coil never gets energized
after the initial read period which precedes cranking). Also, no further decisions are made regarding
authorization level (i.e. the control will not attempt to disable the machine once it has been started).

EMC Testing, Inc Report - MSS.doc 07/17/01

Caterpillar, Inc. Page 7 of 40 EMC – Machine Security System (MSS)

Configuration and Identification of Device Under Test

Description Part Number
MSS ECM (Electronic Control Module) 156-6155 chg 03
MSS ECM PCB Identification 22104-0035
Coil (antenna) 205-8257 chg 00
Key (w/transponder) 206-5165 chg 00
Wiring Harness Test Harness
Key Lock 9G-7641 chg 13
Steel Washer (backing ring for coil) 207-5271 chg 01
Bi-Color LED 165-5655 chg 01

The MSS has two modes of operation: Key Read; and Steady State. During the 210 ms Key Read
period which occurs each time the machine is started the exciter coil is energized for 150 ms. During
the Steady State portion the coil is not energized, but the two output drivers are energized.

For ease of measurement of the RF emissions during the Key Read state the ECM was placed in a
special operating mode in which the coil was constantly energized (identified as “Constant RF” in the
plots).

For steady state operation the MSS ECM was connected to a main power relay (part number 168-7908
chg 03) and a fuel shutoff relay (part number 115-1615 chg 03). These relays remained in a powered
state throughout the duration of the Steady State portion of the test.

A third possibility is one in which an invalid key was read, but in that case the system would remain
inactive and therefore no emissions would be present in that state and no data was taken for that
condition (although the plots would be the same as those shown as “Baseline”).

Plots of data from both modes are attached in the “Tests and Results” section of this document.

The Test Harness used for the wiring harness was representative of a “worst-case” configuration on a
machine.

EMC Testing, Inc Report - MSS.doc 07/17/01

Caterpillar, Inc. Page 8 of 40 EMC – Machine Security System (MSS)

Radiated Emission Limits
The System being tested falls under the category of Intentional Radiators and Digital Devices; subject
to Subparts A & C, Section 15.209 and Subpart B, Section 15.109 (transmitter generated signals
excluded); and Subpart A, Section 15.33. The applicable testing frequencies with corresponding
emission limits are given in the tables below. As a digital device, it is exempt. However since testing
was conducted on the system throughout the entire frequency range up to 1,000 MHz we have
included plots of this data and from them it can be seen that this system complies with Class A
specifications for an intentional radiator.

Section 15.33 Frequency range of radiated measurements

a) Unless otherwise noted in the specific rule section under which the equipment operates for
an intentional radiator, the spectrum shall be investigated from the lowest radio frequency signal
generated in the device, without going below 9 kHz, up to at least the frequency shown in this
paragraph:

1) If the intentional radiator operates below 10 GHz: to the tenth harmonic
of the highest fundamental frequency, or to 40 GHz, whichever is lower.

NOTE: The fundamental frequency of this system is 134.2 kHz, therefore the tenth harmonic is
1.342 MHz.

4) If the intentional radiator contains a digital device, regardless of
whether this digital device controls the functions of the intentional radiator or the digital device is used
for additional control or function purposes other than to enable operation of the intentional radiator, the
frequency range shall be investigated up to the range specified in paragraphs (a)(1)-(a)(3) of this
section or the range applicable to the digital device, as shown in paragraph (b)(1) of this Section,
whichever is the higher frequency range of investigation.

NOTE: According to (b)(1) the maximum frequency for investigation would be 1 GHz
because there are crystals inside the ECM with frequencies as high as 17.1776 MHz, HOWEVER,
based on Section 15.103 Exempted devices subparagraph (a) is states that “a digital device utilized
exclusively in any transportation vehicle including motor vehicles and aircraft” is subject only to
the general conditions of operation in Sections 15.5 and 15.29 and are exempt from the specific
technical standards and other requirements contained in this part.

EMC Testing, Inc Report - MSS.doc 07/17/01

Caterpillar, Inc. Page 9 of 40 EMC – Machine Security System (MSS)

Section 15.209 Radiated emission limits, general requirements

(The following applies to the intentional radiator portion of the Machine Security System)

a) Except as provided elsewhere in this Subpart, the emissions from an intentional radiator shall
not exceed the field strength levels specified in the following table:

Frequency (MHz) Field Strength (uV/m) Meas. Distance (meters)
0.009 – 0.490 2400/F(kHz) 300
0.490 – 1.705 24000/F(kHz) 30
1.705 – 30.0 30 30
30 – 88 100 ** 3
88 – 216 150 ** 3
216 – 960 200 ** 3
above 960 500 3

** Except as provided in paragraph (g), fundamental emissions from intentional radiators operating
under this Section shall not be located in the frequency bands 54-72 MHz,
174-216 MHz or 470-806 MHz. However, operation within these frequency bands is permitted under
other sections of this Part, e.g., Sections 15.231 and 15.241.

NOTE: The fundamental frequency of the Machine Security System (MSS) is 134.2 KHz

As defined by Section 15.31 Measurement standards, subparagraph (f)(1) At frequencies at or above
30 MHz, measurements may be performed at a distance other than what is specified provided:
measurements are appropriate due to the characteristics of the device; and it can be demonstrated that
the signal levels needed to be measured at the distance employed can be detected by the measurement
equipment. Measurement shall not be performed at a distance greater than 30 meters … When
performing measurements at a distance other than that specified the results shall be extrapolated to the
specified distance using an extrapolation factor of 20 dB/decade (inverse linear-distance for field
strength measurements; inverse- linear-distance squared for power density measurements).

c) The level of any unwanted emissions from an intentional radiator operating under these
general provisions shall not exceed the level of the fundamental emission. For intentional radiators
which operate under the provisions of other Sections within this Part and are required to reduce their
unwanted emissions to the limits specified in this table, the limits in this table are based on the
frequency of the unwanted emission and not the fundamental frequency. However the level of any
unwanted emissions shall not exceed the level of the fundamental frequency.

EMC Testing, Inc Report - MSS.doc 07/17/01

Caterpillar, Inc. Page 10 of 40 EMC – Machine Security System
(MSS)
Section 15.109 Radiated Emission limits

b) The field strength of radiated emissions from a Class A digital device, as determined at a
distance of 10 meters, shall not exceed the following:

Frequency of Emission (MHz) Field Strength (uV/m)
30 – 88 90
88 – 216 150
216 – 960 210
above 960 300

under Section 15.3 Definitions subparagraph (h) it defines a Class A digital device as: A digital
device that is marketed for use in commercial, industrial, or business environment, exclusive of a
device which is marketed for use by the general public, or is intended to be used in the ho me.

EMC Testing, Inc Report - MSS.doc 07/17/01

Document Created: 2001-08-03 10:22:25
Document Modified: 2001-08-03 10:22:25

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