Sincronização Precisa de Relógios com FPGA

Prévia do material em texto

A New Design for Precision Clock Synchronization 
Based on FPGA 
Yang. Kong, Jie.Wu, MP. Xie, Zhuan.Yu 
 Abstract–NTP and IEEE1588 are two widely used protocols 
for clock synchronization in large distributed systems. NTP has 
its limitation that the synchronization accuracy is normally no 
better than 1 millisecond. The realization of the IEEE1588 system 
needs expensive components such as high-end microcontrollers 
or dedicated 1588 network hardware. This paper puts forward a 
method based on FPGA and short broadcast frames to realize a 
high level of synchronization accuracy between the master node 
clock and slave node clocks. When the master starts to 
synchronize, it sends a synchronous broadcast frame and 
memorizes this starting time in master clock. Each FPGA of the 
slave nodes, which needs to be synchronized, immediately returns 
a local node information frame as soon as it received the 
broadcast frame. FPGA in the Master measures and memorizes 
the return moment of each node information frame precisely, and 
then calculates the correct value for each node. According to 
these correct values, slave nodes modify the local time to make it 
consistent with the master clock. The experiment result, which is 
done with LVDS data signal on shot wire 10cm and long wire 
55m, shows that the synchronization accuracy is better than 200 
nanoseconds, and the system can maintain the synchronization 
accuracy for a long time. The measured values of clock offset 
between master and slave node clock match well with the 
theoretical values. Experiments show that this design based on 
FPGA can save CPU resources and transmission bandwidth 
effectively for a large distributed system. 
 
 
I. INTRODUCTION 
YNCHRONIZATION is very important for application 
systems such as acquisition systems which are mostly built 
on distributed environment. It is very hard to manage every 
node to work properly as a whole net without a synchronized 
clock. NTP and IEEE1588 are two widely used protocols for 
clock synchronization in large distributed systems. 
 The Precision Timing Protocol (PTP) or IEEE 1588 is an 
emerging standard that addresses the weaknesses of current 
NTP implementations and provides the ability to deliver 
 
Manuscript received February 18, 2009. This work was supported in part 
by the Ministry of Science and Technology of China under Grant 
No.2008ZX05008-05A-004. 
Yang. Yong is with the Department of Modern Physics, University of 
Science and Technology of China, Hefei, CO 230026 China (telephone: 551-
3603654, e-mail: kongy@mail.ustc.edu.cn). 
Jie. Wu is with the Department of Modern Physics, University of Science 
and Technology of China, Hefei, CO 230026 China (telephone: 551-3606496, 
e-mail: wujie@ ustc.edu.cn). 
M.P. Xie is with the Department of Modern Physics, University of Science 
and Technology of China, Hefei, CO 230026 China (telephone: 551-3603654, 
e-mail: mpxie@mail.ustc.edu.cn). 
Zhuan. Yu is with the Department of Modern Physics, University of 
Science and Technology of China, Hefei, CO 230026 China (telephone: 551-
3606496, e-mail: yuzhuan@mail.ustc.edu.cn). 
timing and synchronization over network. The basic difference 
between PTP and NTP is that PTP time stamping is 
implemented in hardware. Achieving a high level of 
synchronization accuracy using IEEE 1588 requires dedicated 
hardware to timestamp messages as close to the physical layer 
as possible [1]. 
 IEEE provide a multicast protocol to achieve 
synchronization for a large network system, but it: “Not scale 
well as the number of clocks increases” [2][3].Nevertheless, it 
was desirable to provide a new method to support time 
synchronization protocol for large distributed systems with a 
great number of nodes, without requiring Ethernet hardware. 
This paper puts forward a method based on FPGA and short 
broadcast frames to realize a high level of synchronization 
accuracy between the master node clock and slave node clocks 
for a large data acquisition system which based on LVDS 
transceivers. 
II. IEEE1588 
 
Fig. 1. IEEE1588 synchronization process. 
 
IEEE 1588 is a master-slave synchronization protocol. The 
main functions of IEEE 1588 protocol are establishing the 
slave nodes clocks synchronized to the master clock and 
making the necessary information available for slave clocks to 
perform this synchronization [4]. Similar to other 
synchronization protocols, IEEE 1588 employs stamping 
certain messages. These special messages are defined as 5 
types, which are called Sync message, Follow_Up message, 
S
2009 16th IEEE-NPSS Real Time Conference TDAP-6
978-1-4244-4455-7/09/$25.00 ©2009 IEEE 411Authorized licensed use limited to: Pontificia Universidade Catolica do Rio Grande do Sul (PUC/RS). Downloaded on September 13,2024 at 01:11:34 UTC from IEEE Xplore. Restrictions apply. 
 
Delay_Req message, Delay_Resp message and management 
message. 
For a given slave device, the offset O(t) at time t is defined by: 
( ) ( ) ( )O t S t M t= − (1) 
where S(t) represents the time measured on the slave device's 
clock at physical time t, and M(t) represents the time measured 
on the master device's clock at physical time t. 
 Each message exchange begins with a multicast sync 
message sent by the master clock to all the slaves listening on 
the PTP multicast group. A slave receiving this message takes 
note of the time T1 measured on its clock when it receives this 
message. The master next sends a multicast time t1 message to 
notify the slaves of time T0 when it sent the sync message. 
Each slave now knows T0 and T1. 
 If d is the transit time of this message, and is the constant 
offset during this transaction, then 
1 0T T O d− = + (2) 
Each slave now sends a respond message back to the master. 
For implementation reasons, this message is implemented as a 
multicast message, but it is a directed multicast message in 
that the packet containing this message includes information 
about the master it is being sent to. The slave measures the 
time T2 that it sends this message, and the master measures 
the time T3 that it receives this message. The master then 
sends a directed multicast time T3 message back to the slave 
to notify the slave what time it received the respond message. 
Note that 
3 2T OT d− = − + (3) 
 The slave now knows times T0, T1, T2, and T3. Combining 
the above two equations, we find that 
1 2 0 3TO = 
2
T T T+ − −
 (4) 
 The slave now knows the offset during this transaction. 
While this offset will drift with time, it will be corrected the 
next time this exchange of transactions is launched [5]. Most 
papers related to IEEE 1588 assume that communication path 
between the master clock and the slave clock is symmetric. 
That’s the reason why one-way delay is calculated as in (3) [4], 
[6], [7], [8]. 
 Slave nodes number is very important to a IEEE 1588 system. 
The more nodes are synchronized the more communication 
bandwidth is took. We take a 1000-nodes line for example (we 
assume synchronization interval is 32ms, and packet length is 
64 Bytes which is the shortest value in Ethernet): 
( ) ( )2 1000 64 8 1000 / 32
32 /
Bitrate Byte ms ms
Mbit S
= × × × ×
=
 (5) 
 Br is the theoretic bit rate of synchronization 
communication. This value reaches 32Mbit/s which is 
intolerable for this 64Mbit/s LVDS data line. 
 Actually, multicast is used to solve this problem which will 
reduce nearly half of synchronization communication 
bandwidth, but even 16Mbit/s is unpractical. Furthermore, the 
behavior of systems building multicast out of point-to-point 
communications will not scale well as the number of clocks 
increases [4]. It can be seen clearly in nodes line. The slave 
nodes send Delay_Req messages at almost the same time, and 
that result a message transmission delta time which is shown 
in Fig 2. 
 
Fig.2. Delta-T influence on synchronization precision. 
 
 Local data timing in Fig 2 indicates the theoretic moment at 
which Delay_Reqmessage should be send by local logic, and 
line data indicates the actual data stream timing in different 
line between each node. Delta-T equals to the time interval 
between the theoretic Delay_Req message sending moment 
and the actual Delay_Req message sending moment. 
412Authorized licensed use limited to: Pontificia Universidade Catolica do Rio Grande do Sul (PUC/RS). Downloaded on September 13,2024 at 01:11:34 UTC from IEEE Xplore. Restrictions apply. 
 
 When line1 of slave1 is busy, all the data of line2 must be 
stored in local buffer and will be sent few clocks latter. Since 
the instantaneous stream density is much greater than the 
channel bandwidth, the more nodes there are in data line the 
worse line accumulation time can be. 
 Sync messages are broadcast messages and Delta-T delay 
only exist on Delay_Req message transmissions, so the D 
parameter in master-to-slave channel is not equal to what in 
slave-to-master channel. Delta-T affects synchronization 
precision by its half value multiply the number slave nodes, 
and this affection can reach millisecond range. 
 Conclusions above are carried out on the premise of all 
nodes in a serial data line. If there is a ramose structure in the 
zone to be synchronized by one broadcast sync message, 
situations turn to be very complicated, and the data bandwidth 
in each ramification is very important to synchronization 
precision. 
 
III. SHORT FRAME SOLUTION IN 
This short frame solution is designed for a large distributed 
data acquisition system. This system consists of a mass of data 
unit (D-units) and some transmission units (T-units) which are 
shown in Fig 3. T-units are the first level unit, and D-units are 
the second level units. 
 
Fig. 3. Large Distributed Data Acquisition System 
 
D-unit to D-units and D-units to T-units data-lines are 
based on LVDS transmission, and T-units to T-units are based 
on Gigabit Ethernet technology. Synchronization precisions 
are tested on LVDS unit’s transmission line. The transceivers 
SN65LV1023/ SN65LV1024 produced by Texas Instruments 
and FPGA XC3S100E produced by Xilinx are the main data-
line chips. 
The short frame for this distributed system is much shorter 
than IEEE 1588 Ethernet frame which has a minimal 64 Byte 
length. Frame segment and exact frame length value which is 
14 Byte in this application can be set as the designer like and 
this design can save a lot of bandwidth. Fig 4 shows the short 
frame segment. 
(4 Bits)
TypeTarget address Target UnitSource address
Source address: slave node address
Type:
Target Unit:
(6 Byte) (6 Byte) (4 Bits)
Target address:
Short frame segment
0x1 Sync respond message
0x0 Sync broadcast message
0x0 T-unit
0xfffffffffffe
Checksum
(1 Byte)
Checksum: 1 Byte checksum
0x1 D-unit
 
Fig. 4. Short Frame Segment 
 
 
Fig. 5. Unit Hardware Structure 
 
Target address area is a 6-bytes 0xfffffffffffe address, this 
apart a short frame message frame from other data frames. A 
frame consists of Target address, Source address, Type, Target 
Unit and Check sum only if the first six byte of the frame is 
0xfffffffffffe. Source address area is a 6-bytes address to 
identify the source of the frame. This address should be used 
as a target address by slave units in a respond frame. Type and 
Target Unit are two 4-bit symbols to indicate message type 
(broadcast message or respond message) and target unit type 
(D-unit or T-unit). 
Sync broadcast messages and Sync respond messages 
consist of short frames, and Delay Modify messages are 
similar to Ethernet broadcast frames which are more complex 
and contain more information. 
Fig 6 shows these master slave communications. The 
master send a Sync message and the slave returns a Delay 
message to make sure they can register the exact time of t0, t1, 
t2, and t3. This protocol does not contain a Follow_Up 
message. 
FPGA logic of slave nodes with special design is very 
important to remove Delta T affection. The transmit logic of 
slave nodes add a 16-Byte delay for each package. This delay 
413Authorized licensed use limited to: Pontificia Universidade Catolica do Rio Grande do Sul (PUC/RS). Downloaded on September 13,2024 at 01:11:34 UTC from IEEE Xplore. Restrictions apply. 
 
makes the point to point message transmission time almost a 
fixed value. 
 
Fig. 6. Short Frame synchronization process. 
When the master starts to synchronize, it sends a Sync 
broadcast message and memorizes this starting time (T0) 
exactly in master clock register. When a salve node detect a 
full frame of sync message, it register the receiving start time 
(T1) by its local clock and start to send back a Sync respond 
message a few clocks later after the sync message because 
these are done in FPGA logic. Sync respond message have the 
same segment of short frame segment .There is no CPU 
participation in creating and sending Sync respond messages 
and The exactly time (T2) of sending this Sync respond 
message is also memorize by the slave nodes. As a result of 
the Sync broadcast message, the master gets a large amount of 
Sync respond messages of all salve nodes. As there is a source 
address information in short frame segment, the master 
memorize the exactly receiving time (T3) of each Sync 
respond message and its source address in FPGA. The Master 
will send T0 and T3 to the salve as soon as it gets T3. 
The whole system can not get synchronization by a single 
sync process because the system has a ramose structure. There 
is a great synchronization accuracy losing at the data-line 
cross points. The more D-units there are in a T-line the more 
accuracy it loses. A two level synchronization solution must 
be used to make T-units and D-units get synchronized 
independently. 
At first, T-units are synchronized to the control machine by 
a T-unit broadcast (the Target Unit zone is filled with 0x0). 
After that, T-units send D-unit broadcast (the Target Unit zone 
is filled with 0x1) to control the D-units synchronize to them. 
The whole system reach synchronization by this two-level 
sync and the units of these two levels keep synchronization 
separately. 
IV. RESULTS AND CONCLUSION 
 A lot of tests have been done on D-unit data lines. The D-
unit interval can be as far as 55 meters and synchronization 
precision also be tested with 5 meters and 12 meters 
transmission lines. Experiment on 12 meters D-unit data lines 
shows that the synchronization accuracy is better than 200 
nanoseconds with this new short frame protocol based on 
FPGA. Experiments on data lines with other length such as 5 
meters and 55 meters came out the same accuracy level. 
 
Fig. 7. Synchronization Pulse. 
 
 In conclusion, this new short frame solution can save data 
line bandwidth effectively and make the system get rid of 
dedicated synchronization hardware. FPGA based short frame 
solution over LVDS transmission line can be used to 
synchronize a network of distributed data acquisition system. 
REFERENCES 
[1] Rosselot David, “Simple, accurate time synchronization in an ethernet 
physical layer device,” 2007 IEEE International Symposium on 
Precision Clock Synchronization for Measurement, Control and 
Communication, ISPCS 2007 Proceedings, pp. 123–127, 2007 IEEE 
International Symposium on Precision Clock Synchronization for 
Measurement, Control and Communication, ISPCS 2007 Proceedings. 
[2] IEEE Instrumentation and Measurement Society, “IEEE 1588 Standard 
for a Precision Clock Synchronization Protocol for Networked 
Measurement and Control Systems (IEEE Std 1588-2002).”. 
[3] IEEE Instrumentation and Measurement Society, “IEEE 1588 Standard 
for a Precision Clock Synchronization Protocol for Networked 
Measurement and Control Systems (IEEE Std 61588-2004).”. 
[4] Lee Sungwon, “ An enhanced IEEE 1588 time synchronization 
algorithm for asymmetric communication link using block burst 
transmission,” IEEE Communications Letters, v 12, n 9, p 687-689, 
2008.[5] Eidson, John C, Measurement, Control and Communication Using IEEE 
1588,(April 2006).,ISBN 1-8462-8250-0. 
[6] T. Cooklev, J. C. Eidson, and A. Pakdaman, “An implementation of 
IEEE 1588 over IEEE 802.11b for synchronization of wireless LAN area 
network nodes,” IEEE Trans. Instrumentation and Measurement, vol. 
56, no. 5, pp. 1632–1639, Oct. 2007. 
[7] P. Ferrari, A. Flammini, D. Marioli, and A. Taroni, “IEEE 1588 based 
synchronization system for a displacement sensor network,” IEEE 
Trans. Instrumentation and Measurement, vol. 57, no. 2, Feb. 20081992. 
[8] A. Vallat and D. Scheuwly, “Clock synchronization in 
telecommunications via PTP (IEEE 1588),” in Proc. IEEE International 
Frequency Control Symposium Joint with the 21st European Frequency 
and Time Forum, pp. 334–341, May 2007. 
414Authorized licensed use limited to: Pontificia Universidade Catolica do Rio Grande do Sul (PUC/RS). Downloaded on September 13,2024 at 01:11:34 UTC from IEEE Xplore. Restrictions apply. 
/CMSSQI8
 /CMSY10
 /CMSY5
 /CMSY6
 /CMSY7
 /CMSY8
 /CMSY9
 /CMTCSC10
 /CMTEX10
 /CMTEX8
 /CMTEX9
 /CMTI10
 /CMTI12
 /CMTI7
 /CMTI8
 /CMTI9
 /CMTT10
 /CMTT12
 /CMTT8
 /CMTT9
 /CMU10
 /CMVTT10
 /ColonnaMT
 /Colossalis-Bold
 /ComicSansMS
 /ComicSansMS-Bold
 /Consolas
 /Consolas-Bold
 /Consolas-BoldItalic
 /Consolas-Italic
 /Constantia
 /Constantia-Bold
 /Constantia-BoldItalic
 /Constantia-Italic
 /CooperBlack
 /CopperplateGothic-Bold
 /CopperplateGothic-Light
 /Copperplate-ThirtyThreeBC
 /Corbel
 /Corbel-Bold
 /Corbel-BoldItalic
 /Corbel-Italic
 /CordiaNew
 /CordiaNew-Bold
 /CordiaNew-BoldItalic
 /CordiaNew-Italic
 /CordiaUPC
 /CordiaUPC-Bold
 /CordiaUPC-BoldItalic
 /CordiaUPC-Italic
 /Courier
 /Courier-Bold
 /Courier-BoldOblique
 /CourierNewPS-BoldItalicMT
 /CourierNewPS-BoldMT
 /CourierNewPS-ItalicMT
 /CourierNewPSMT
 /Courier-Oblique
 /CourierStd
 /CourierStd-Bold
 /CourierStd-BoldOblique
 /CourierStd-Oblique
 /CourierX-Bold
 /CourierX-BoldOblique
 /CourierX-Oblique
 /CourierX-Regular
 /CreepyRegular
 /CurlzMT
 /David-Bold
 /David-Reg
 /DavidTransparent
 /Desdemona
 /DilleniaUPC
 /DilleniaUPCBold
 /DilleniaUPCBoldItalic
 /DilleniaUPCItalic
 /Dingbats
 /DomCasual
 /Dotum
 /DotumChe
 /EdwardianScriptITC
 /Elephant-Italic
 /Elephant-Regular
 /EngraversGothicBT-Regular
 /EngraversMT
 /EraserDust
 /ErasITC-Bold
 /ErasITC-Demi
 /ErasITC-Light
 /ErasITC-Medium
 /ErieBlackPSMT
 /ErieLightPSMT
 /EriePSMT
 /EstrangeloEdessa
 /Euclid
 /Euclid-Bold
 /Euclid-BoldItalic
 /EuclidExtra
 /EuclidExtra-Bold
 /EuclidFraktur
 /EuclidFraktur-Bold
 /Euclid-Italic
 /EuclidMathOne
 /EuclidMathOne-Bold
 /EuclidMathTwo
 /EuclidMathTwo-Bold
 /EuclidSymbol
 /EuclidSymbol-Bold
 /EuclidSymbol-BoldItalic
 /EuclidSymbol-Italic
 /EucrosiaUPC
 /EucrosiaUPCBold
 /EucrosiaUPCBoldItalic
 /EucrosiaUPCItalic
 /EUEX10
 /EUEX7
 /EUEX8
 /EUEX9
 /EUFB10
 /EUFB5
 /EUFB7
 /EUFM10
 /EUFM5
 /EUFM7
 /EURB10
 /EURB5
 /EURB7
 /EURM10
 /EURM5
 /EURM7
 /EuroMono-Bold
 /EuroMono-BoldItalic
 /EuroMono-Italic
 /EuroMono-Regular
 /EuroSans-Bold
 /EuroSans-BoldItalic
 /EuroSans-Italic
 /EuroSans-Regular
 /EuroSerif-Bold
 /EuroSerif-BoldItalic
 /EuroSerif-Italic
 /EuroSerif-Regular
 /EuroSig
 /EUSB10
 /EUSB5
 /EUSB7
 /EUSM10
 /EUSM5
 /EUSM7
 /FelixTitlingMT
 /Fences
 /FencesPlain
 /FigaroMT
 /FixedMiriamTransparent
 /FootlightMTLight
 /Formata-Italic
 /Formata-Medium
 /Formata-MediumItalic
 /Formata-Regular
 /ForteMT
 /FranklinGothic-Book
 /FranklinGothic-BookItalic
 /FranklinGothic-Demi
 /FranklinGothic-DemiCond
 /FranklinGothic-DemiItalic
 /FranklinGothic-Heavy
 /FranklinGothic-HeavyItalic
 /FranklinGothicITCbyBT-Book
 /FranklinGothicITCbyBT-BookItal
 /FranklinGothicITCbyBT-Demi
 /FranklinGothicITCbyBT-DemiItal
 /FranklinGothic-Medium
 /FranklinGothic-MediumCond
 /FranklinGothic-MediumItalic
 /FrankRuehl
 /FreesiaUPC
 /FreesiaUPCBold
 /FreesiaUPCBoldItalic
 /FreesiaUPCItalic
 /FreestyleScript-Regular
 /FrenchScriptMT
 /Frutiger-Black
 /Frutiger-BlackCn
 /Frutiger-BlackItalic
 /Frutiger-Bold
 /Frutiger-BoldCn
 /Frutiger-BoldItalic
 /Frutiger-Cn
 /Frutiger-ExtraBlackCn
 /Frutiger-Italic
 /Frutiger-Light
 /Frutiger-LightCn
 /Frutiger-LightItalic
 /Frutiger-Roman
 /Frutiger-UltraBlack
 /Futura-Bold
 /Futura-BoldOblique
 /Futura-Book
 /Futura-BookOblique
 /FuturaBT-Bold
 /FuturaBT-BoldItalic
 /FuturaBT-Book
 /FuturaBT-BookItalic
 /FuturaBT-Medium
 /FuturaBT-MediumItalic
 /Futura-Light
 /Futura-LightOblique
 /GalliardITCbyBT-Bold
 /GalliardITCbyBT-BoldItalic
 /GalliardITCbyBT-Italic
 /GalliardITCbyBT-Roman
 /Garamond
 /Garamond-Bold
 /Garamond-BoldCondensed
 /Garamond-BoldCondensedItalic
 /Garamond-BoldItalic
 /Garamond-BookCondensed
 /Garamond-BookCondensedItalic
 /Garamond-Italic
 /Garamond-LightCondensed
 /Garamond-LightCondensedItalic
 /Gautami
 /GeometricSlab703BT-Light
 /GeometricSlab703BT-LightItalic
 /Georgia
 /Georgia-Bold
 /Georgia-BoldItalic
 /Georgia-Italic
 /GeorgiaRef
 /Giddyup
 /Giddyup-Thangs
 /Gigi-Regular
 /GillSans
 /GillSans-Bold
 /GillSans-BoldItalic
 /GillSans-Condensed
 /GillSans-CondensedBold
 /GillSans-Italic
 /GillSans-Light
 /GillSans-LightItalic
 /GillSansMT
 /GillSansMT-Bold
 /GillSansMT-BoldItalic
 /GillSansMT-Condensed
 /GillSansMT-ExtraCondensedBold
 /GillSansMT-Italic
 /GillSans-UltraBold
 /GillSans-UltraBoldCondensed
 /GloucesterMT-ExtraCondensed
 /Gothic-Thirteen
 /GoudyOldStyleBT-Bold
 /GoudyOldStyleBT-BoldItalic
 /GoudyOldStyleBT-Italic
 /GoudyOldStyleBT-Roman
 /GoudyOldStyleT-Bold
 /GoudyOldStyleT-Italic
 /GoudyOldStyleT-Regular
 /GoudyStout
 /GoudyTextMT-LombardicCapitals
 /GSIDefaultSymbols
 /Gulim
 /GulimChe
 /Gungsuh
 /GungsuhChe
 /Haettenschweiler
 /HarlowSolid
 /Harrington
 /Helvetica
 /Helvetica-Black
 /Helvetica-BlackOblique
 /Helvetica-Bold
 /Helvetica-BoldOblique
 /Helvetica-Condensed
 /Helvetica-Condensed-Black
 /Helvetica-Condensed-BlackObl
 /Helvetica-Condensed-Bold
 /Helvetica-Condensed-BoldObl
 /Helvetica-Condensed-Light
 /Helvetica-Condensed-LightObl
 /Helvetica-Condensed-Oblique
 /Helvetica-Fraction
 /Helvetica-Narrow
 /Helvetica-Narrow-Bold
 /Helvetica-Narrow-BoldOblique
 /Helvetica-Narrow-Oblique
 /Helvetica-Oblique
 /HighTowerText-Italic
 /HighTowerText-Reg
 /Humanist521BT-BoldCondensed
 /Humanist521BT-Light
 /Humanist521BT-LightItalic
 /Humanist521BT-RomanCondensed
 /Imago-ExtraBold
 /Impact
 /ImprintMT-Shadow
 /InformalRoman-Regular
 /IrisUPC
 /IrisUPCBold
 /IrisUPCBoldItalic
 /IrisUPCItalic
 /Ironwood
 /ItcEras-Medium
 /ItcKabel-Bold
 /ItcKabel-Book
 /ItcKabel-Demi
 /ItcKabel-Medium
 /ItcKabel-Ultra
 /JasmineUPC
 /JasmineUPC-Bold
 /JasmineUPC-BoldItalic
 /JasmineUPC-Italic
 /JoannaMT
 /JoannaMT-Italic
 /Jokerman-Regular
 /JuiceITC-Regular
 /Kartika
 /Kaufmann
 /KaufmannBT-Bold
 /KaufmannBT-Regular
 /KidTYPEPaint
 /KinoMT
 /KodchiangUPC
 /KodchiangUPC-Bold
 /KodchiangUPC-BoldItalic
 /KodchiangUPC-Italic
 /KorinnaITCbyBT-Regular
 /KozGoProVI-Medium
 /KozMinProVI-Regular
 /KristenITC-Regular
 /KunstlerScript
 /Latha
 /LatinWide
 /LetterGothic
 /LetterGothic-Bold
 /LetterGothic-BoldOblique
 /LetterGothic-BoldSlanted
 /LetterGothicMT
 /LetterGothicMT-Bold
 /LetterGothicMT-BoldOblique
 /LetterGothicMT-Oblique
 /LetterGothic-Slanted
 /LetterGothicStd
 /LetterGothicStd-Bold
 /LetterGothicStd-BoldSlanted
 /LetterGothicStd-Slanted
 /LevenimMT
 /LevenimMTBold
 /LilyUPC
 /LilyUPCBold
 /LilyUPCBoldItalic
 /LilyUPCItalic
 /Lithos-Black
 /Lithos-Regular
 /LotusWPBox-Roman
 /LotusWPIcon-Roman
 /LotusWPIntA-Roman
 /LotusWPIntB-Roman
 /LotusWPType-Roman
 /LucidaBright
 /LucidaBright-Demi
 /LucidaBright-DemiItalic
 /LucidaBright-Italic
 /LucidaCalligraphy-Italic
 /LucidaConsole
 /LucidaFax
 /LucidaFax-Demi
 /LucidaFax-DemiItalic
 /LucidaFax-Italic
 /LucidaHandwriting-Italic
 /LucidaSans
 /LucidaSans-Demi
 /LucidaSans-DemiItalic
 /LucidaSans-Italic
 /LucidaSans-Typewriter
 /LucidaSans-TypewriterBold
 /LucidaSans-TypewriterBoldOblique
 /LucidaSans-TypewriterOblique
 /LucidaSansUnicode
 /Lydian
 /Magneto-Bold/MaiandraGD-Regular
 /Mangal-Regular
 /Map-Symbols
 /MathA
 /MathB
 /MathC
 /Mathematica1
 /Mathematica1-Bold
 /Mathematica1Mono
 /Mathematica1Mono-Bold
 /Mathematica2
 /Mathematica2-Bold
 /Mathematica2Mono
 /Mathematica2Mono-Bold
 /Mathematica3
 /Mathematica3-Bold
 /Mathematica3Mono
 /Mathematica3Mono-Bold
 /Mathematica4
 /Mathematica4-Bold
 /Mathematica4Mono
 /Mathematica4Mono-Bold
 /Mathematica5
 /Mathematica5-Bold
 /Mathematica5Mono
 /Mathematica5Mono-Bold
 /Mathematica6
 /Mathematica6Bold
 /Mathematica6Mono
 /Mathematica6MonoBold
 /Mathematica7
 /Mathematica7Bold
 /Mathematica7Mono
 /Mathematica7MonoBold
 /MatisseITC-Regular
 /MaturaMTScriptCapitals
 /Mesquite
 /Mezz-Black
 /Mezz-Regular
 /MICR
 /MicrosoftSansSerif
 /MingLiU
 /Minion-BoldCondensed
 /Minion-BoldCondensedItalic
 /Minion-Condensed
 /Minion-CondensedItalic
 /Minion-Ornaments
 /MinionPro-Bold
 /MinionPro-BoldIt
 /MinionPro-It
 /MinionPro-Regular
 /MinionPro-Semibold
 /MinionPro-SemiboldIt
 /Miriam
 /MiriamFixed
 /MiriamTransparent
 /Mistral
 /Modern-Regular
 /MonotypeCorsiva
 /MonotypeSorts
 /MSAM10
 /MSAM5
 /MSAM6
 /MSAM7
 /MSAM8
 /MSAM9
 /MSBM10
 /MSBM5
 /MSBM6
 /MSBM7
 /MSBM8
 /MSBM9
 /MS-Gothic
 /MSHei
 /MSLineDrawPSMT
 /MS-Mincho
 /MSOutlook
 /MS-PGothic
 /MS-PMincho
 /MSReference1
 /MSReference2
 /MSReferenceSansSerif
 /MSReferenceSansSerif-Bold
 /MSReferenceSansSerif-BoldItalic
 /MSReferenceSansSerif-Italic
 /MSReferenceSerif
 /MSReferenceSerif-Bold
 /MSReferenceSerif-BoldItalic
 /MSReferenceSerif-Italic
 /MSReferenceSpecialty
 /MSSong
 /MS-UIGothic
 /MT-Extra
 /MT-Symbol
 /MT-Symbol-Italic
 /MVBoli
 /Myriad-Bold
 /Myriad-BoldItalic
 /Myriad-Italic
 /MyriadPro-Black
 /MyriadPro-BlackIt
 /MyriadPro-Bold
 /MyriadPro-BoldIt
 /MyriadPro-It
 /MyriadPro-Light
 /MyriadPro-LightIt
 /MyriadPro-Regular
 /MyriadPro-Semibold
 /MyriadPro-SemiboldIt
 /Myriad-Roman
 /Narkisim
 /NewCenturySchlbk-Bold
 /NewCenturySchlbk-BoldItalic
 /NewCenturySchlbk-Italic
 /NewCenturySchlbk-Roman
 /NewMilleniumSchlbk-BoldItalicSH
 /NewsGothic
 /NewsGothic-Bold
 /NewsGothicBT-Bold
 /NewsGothicBT-BoldItalic
 /NewsGothicBT-Italic
 /NewsGothicBT-Roman
 /NewsGothic-Condensed
 /NewsGothic-Italic
 /NewsGothicMT
 /NewsGothicMT-Bold
 /NewsGothicMT-Italic
 /NiagaraEngraved-Reg
 /NiagaraSolid-Reg
 /NimbusMonL-Bold
 /NimbusMonL-BoldObli
 /NimbusMonL-Regu
 /NimbusMonL-ReguObli
 /NimbusRomNo9L-Medi
 /NimbusRomNo9L-MediItal
 /NimbusRomNo9L-Regu
 /NimbusRomNo9L-ReguItal
 /NimbusSanL-Bold
 /NimbusSanL-BoldCond
 /NimbusSanL-BoldCondItal
 /NimbusSanL-BoldItal
 /NimbusSanL-Regu
 /NimbusSanL-ReguCond
 /NimbusSanL-ReguCondItal
 /NimbusSanL-ReguItal
 /Nimrod
 /Nimrod-Bold
 /Nimrod-BoldItalic
 /Nimrod-Italic
 /NSimSun
 /Nueva-BoldExtended
 /Nueva-BoldExtendedItalic
 /Nueva-Italic
 /Nueva-Roman
 /NuptialScript
 /OCRA
 /OCRA-Alternate
 /OCRAExtended
 /OCRB
 /OCRB-Alternate
 /OfficinaSans-Bold
 /OfficinaSans-BoldItalic
 /OfficinaSans-Book
 /OfficinaSans-BookItalic
 /OfficinaSerif-Bold
 /OfficinaSerif-BoldItalic
 /OfficinaSerif-Book
 /OfficinaSerif-BookItalic
 /OldEnglishTextMT
 /Onyx
 /OnyxBT-Regular
 /OzHandicraftBT-Roman
 /PalaceScriptMT
 /Palatino-Bold
 /Palatino-BoldItalic
 /Palatino-Italic
 /PalatinoLinotype-Bold
 /PalatinoLinotype-BoldItalic
 /PalatinoLinotype-Italic
 /PalatinoLinotype-Roman
 /Palatino-Roman
 /PapyrusPlain
 /Papyrus-Regular
 /Parchment-Regular
 /Parisian
 /ParkAvenue
 /Penumbra-SemiboldFlare
 /Penumbra-SemiboldSans
 /Penumbra-SemiboldSerif
 /PepitaMT
 /Perpetua
 /Perpetua-Bold
 /Perpetua-BoldItalic
 /Perpetua-Italic
 /PerpetuaTitlingMT-Bold
 /PerpetuaTitlingMT-Light
 /PhotinaCasualBlack
 /Playbill
 /PMingLiU
 /Poetica-SuppOrnaments
 /PoorRichard-Regular
 /PopplLaudatio-Italic
 /PopplLaudatio-Medium
 /PopplLaudatio-MediumItalic
 /PopplLaudatio-Regular
 /PrestigeElite
 /Pristina-Regular
 /PTBarnumBT-Regular
 /Raavi
 /RageItalic
 /Ravie
 /RefSpecialty
 /Ribbon131BT-Bold
 /Rockwell
 /Rockwell-Bold
 /Rockwell-BoldItalic
 /Rockwell-Condensed
 /Rockwell-CondensedBold
 /Rockwell-ExtraBold
 /Rockwell-Italic
 /Rockwell-Light
 /Rockwell-LightItalic
 /Rod
 /RodTransparent
 /RunicMT-Condensed
 /Sanvito-Light
 /Sanvito-Roman
 /ScriptC
 /ScriptMTBold
 /SegoeUI
 /SegoeUI-Bold
 /SegoeUI-BoldItalic
 /SegoeUI-Italic
 /Serpentine-BoldOblique
 /ShelleyVolanteBT-Regular
 /ShowcardGothic-Reg
 /Shruti
 /SimHei
 /SimSun
 /SnapITC-Regular
 /StandardSymL
 /Stencil
 /StoneSans
 /StoneSans-Bold
 /StoneSans-BoldItalic
 /StoneSans-Italic
 /StoneSans-Semibold
 /StoneSans-SemiboldItalic
 /Stop
 /Swiss721BT-BlackExtended
 /Sylfaen
 /Symbol
 /SymbolMT
 /Tahoma
 /Tahoma-Bold
 /Tci1
 /Tci1Bold
 /Tci1BoldItalic
 /Tci1Italic
 /Tci2
 /Tci2Bold
 /Tci2BoldItalic
 /Tci2Italic
 /Tci3
 /Tci3Bold
 /Tci3BoldItalic
 /Tci3Italic
 /Tci4
 /Tci4Bold
 /Tci4BoldItalic
 /Tci4Italic
 /TechnicalItalic
 /TechnicalPlain
 /Tekton
 /Tekton-Bold
 /TektonMM
 /Tempo-HeavyCondensed
 /Tempo-HeavyCondensedItalic
 /TempusSansITC
 /Times-Bold
 /Times-BoldItalic
 /Times-BoldItalicOsF
 /Times-BoldSC
 /Times-ExtraBold
 /Times-Italic
 /Times-ItalicOsF
 /TimesNewRomanMT-ExtraBold
 /TimesNewRomanPS-BoldItalicMT
 /TimesNewRomanPS-BoldMT
 /TimesNewRomanPS-ItalicMT
 /TimesNewRomanPSMT
 /Times-Roman
 /Times-RomanSC
 /Trajan-Bold
 /Trebuchet-BoldItalic
 /TrebuchetMS
 /TrebuchetMS-Bold
 /TrebuchetMS-Italic
 /Tunga-Regular
 /TwCenMT-Bold
 /TwCenMT-BoldItalic
 /TwCenMT-Condensed
 /TwCenMT-CondensedBold
 /TwCenMT-CondensedExtraBold
 /TwCenMT-CondensedMedium
 /TwCenMT-Italic
 /TwCenMT-Regular
 /Univers-Bold
 /Univers-BoldItalic
 /UniversCondensed-Bold
 /UniversCondensed-BoldItalic
 /UniversCondensed-Medium
 /UniversCondensed-MediumItalic
 /Univers-Medium
 /Univers-MediumItalic
 /URWBookmanL-DemiBold
 /URWBookmanL-DemiBoldItal
 /URWBookmanL-Ligh
 /URWBookmanL-LighItal
 /URWChanceryL-MediItal
 /URWGothicL-Book
 /URWGothicL-BookObli
 /URWGothicL-Demi
 /URWGothicL-DemiObli
 /URWPalladioL-Bold
 /URWPalladioL-BoldItal
 /URWPalladioL-Ital
 /URWPalladioL-Roma
 /USPSBarCode
 /VAGRounded-Black
 /VAGRounded-Bold
 /VAGRounded-Light
 /VAGRounded-Thin
 /Verdana
 /Verdana-Bold
 /Verdana-BoldItalic
 /Verdana-Italic
 /VerdanaRef
 /VinerHandITC
 /Viva-BoldExtraExtended
 /Vivaldii
 /Viva-LightCondensed
 /Viva-Regular
 /VladimirScript
 /Vrinda
 /Webdings
 /Westminster
 /Willow
 /Wingdings2
 /Wingdings3
 /Wingdings-Regular
 /WNCYB10
 /WNCYI10
 /WNCYR10
 /WNCYSC10
 /WNCYSS10
 /WoodtypeOrnaments-One
 /WoodtypeOrnaments-Two
 /WP-ArabicScriptSihafa
 /WP-ArabicSihafa
 /WP-BoxDrawing
 /WP-CyrillicA
 /WP-CyrillicB
 /WP-GreekCentury
 /WP-GreekCourier
 /WP-GreekHelve
 /WP-HebrewDavid
 /WP-IconicSymbolsA
 /WP-IconicSymbolsB
 /WP-Japanese
 /WP-MathA
 /WP-MathB
 /WP-MathExtendedA
 /WP-MathExtendedB
 /WP-MultinationalAHelve
 /WP-MultinationalARoman
 /WP-MultinationalBCourier
 /WP-MultinationalBHelve
 /WP-MultinationalBRoman
 /WP-MultinationalCourier
 /WP-Phonetic
 /WPTypographicSymbols
 /XYATIP10
 /XYBSQL10
 /XYBTIP10
 /XYCIRC10
 /XYCMAT10/XYCMBT10
 /XYDASH10
 /XYEUAT10
 /XYEUBT10
 /ZapfChancery-MediumItalic
 /ZapfDingbats
 /ZapfHumanist601BT-Bold
 /ZapfHumanist601BT-BoldItalic
 /ZapfHumanist601BT-Demi
 /ZapfHumanist601BT-DemiItalic
 /ZapfHumanist601BT-Italic
 /ZapfHumanist601BT-Roman
 /ZWAdobeF
 ]
 /NeverEmbed [ true
 ]
 /AntiAliasColorImages false
 /CropColorImages true
 /ColorImageMinResolution 200
 /ColorImageMinResolutionPolicy /OK
 /DownsampleColorImages true
 /ColorImageDownsampleType /Bicubic
 /ColorImageResolution 300
 /ColorImageDepth -1
 /ColorImageMinDownsampleDepth 1
 /ColorImageDownsampleThreshold 2.00333
 /EncodeColorImages true
 /ColorImageFilter /DCTEncode
 /AutoFilterColorImages true
 /ColorImageAutoFilterStrategy /JPEG
 /ColorACSImageDict >
 /ColorImageDict >
 /JPEG2000ColorACSImageDict >
 /JPEG2000ColorImageDict >
 /AntiAliasGrayImages false
 /CropGrayImages true
 /GrayImageMinResolution 200
 /GrayImageMinResolutionPolicy /OK
 /DownsampleGrayImages true
 /GrayImageDownsampleType /Bicubic
 /GrayImageResolution 300
 /GrayImageDepth -1
 /GrayImageMinDownsampleDepth 2
 /GrayImageDownsampleThreshold 2.00333
 /EncodeGrayImages true
 /GrayImageFilter /DCTEncode
 /AutoFilterGrayImages true
 /GrayImageAutoFilterStrategy /JPEG
 /GrayACSImageDict >
 /GrayImageDict >
 /JPEG2000GrayACSImageDict >
 /JPEG2000GrayImageDict >
 /AntiAliasMonoImages false
 /CropMonoImages true
 /MonoImageMinResolution 400
 /MonoImageMinResolutionPolicy /OK
 /DownsampleMonoImages true
 /MonoImageDownsampleType /Bicubic
 /MonoImageResolution 600
 /MonoImageDepth -1
 /MonoImageDownsampleThreshold 1.00167
 /EncodeMonoImages true
 /MonoImageFilter /CCITTFaxEncode
 /MonoImageDict >
 /AllowPSXObjects false
 /CheckCompliance [
 /None
 ]
 /PDFX1aCheck false
 /PDFX3Check false
 /PDFXCompliantPDFOnly false
 /PDFXNoTrimBoxError true
 /PDFXTrimBoxToMediaBoxOffset [
 0.00000
 0.00000
 0.00000
 0.00000
 ]
 /PDFXSetBleedBoxToMediaBox true
 /PDFXBleedBoxToTrimBoxOffset [
 0.00000
 0.00000
 0.00000
 0.00000
 ]
 /PDFXOutputIntentProfile (None)
 /PDFXOutputConditionIdentifier ()
 /PDFXOutputCondition ()
 /PDFXRegistryName ()
 /PDFXTrapped /False
 /CreateJDFFile false
 /Description 
 /BGR 
 /CHS 
 /CHT 
 /CZE 
 /DAN 
 /DEU/ESP 
 /ETI 
 /FRA 
 /GRE 
 /HEB 
 /HRV 
 /HUN 
 /ITA/JPN 
 /KOR 
 /LTH 
 /LVI 
 /NLD (Gebruik deze instellingen om Adobe PDF-documenten te maken die zijn geoptimaliseerd voor weergave op een beeldscherm, e-mail en internet. De gemaakte PDF-documenten kunnen worden geopend met Acrobat en Adobe Reader 5.0 en hoger.)
 /NOR 
 /POL 
 /PTB 
 /RUM 
 /RUS 
 /SKY/SLV 
 /SUO 
 /SVE 
 /TUR 
 /UKR 
 /ENU (Use these settings to create Adobe PDF documents best suited for on-screen display, e-mail, and the Internet. Created PDF documents can be opened with Acrobat and Adobe Reader 5.0 and later.)
 >>
 /Namespace [
 (Adobe)
 (Common)
 (1.0)
 ]
 /OtherNamespaces [
 >
 >
 /FormElements false
 /GenerateStructure false
 /IncludeBookmarks false
 /IncludeHyperlinks false
 /IncludeInteractive false
 /IncludeLayers false
 /IncludeProfiles true
 /MultimediaHandling /UseObjectSettings
 /Namespace [
 (Adobe)
 (CreativeSuite)
 (2.0)
 ]
 /PDFXOutputIntentProfileSelector /NA
 /PreserveEditing false
 /UntaggedCMYKHandling /UseDocumentProfile
 /UntaggedRGBHandling /UseDocumentProfile
 /UseDocumentBleed false
 >>
 ]
>> setdistillerparams
> setpagedevice