TN-101 SER System Architectures

Sequence of Events Recording (SER) System Architectures

TECHNICAL NOTE

TN-101Sep-2009

Power Reliability and Energy Efficiency. Enabled.SM

IntroductionPower system devices such as power meters and protective relays with onboard clocks often include provisions for synchronizing to a known accurate time source, such as a GPS time signal. Protocols typically used include IRIG-B, DCF77 and 1per10. The number of devices to be synchronized, the protocols used, and the distances involved may all affect system architecture.

System ComponentsA typical SER system includes a GPS antenna mounted on the roof or other external location allowing line-of-sight access to multiple satel-lites. A GPS receiver or satellite time reference decodes the antenna’s GPS time data and outputs a precision time signal using one or more protocols, as needed. The figure below shows a simple SER system using one Cyber Sciences STR-100 Satellite Time Reference (with in-put from a Trimble Acutime Gold GPS “smart antenna”) to synchronize devices that support DCF77, 1per10 or IRIG-B protocols.

System ArchitecturesA generic SER system architecture concept drawing is shown below. The remainder of this document includes architecture examples for common application scenarios.

GPS Receiver /Satellite Time Reference

GPS antenna

Power System Device

Power System Device

Power System Device

DCF77 1per10 IRIG-B

SER system architecture concept drawing

SummaryCritical power applications require preci-sion timing for monitoring and control. Sequence of Events Recording (SER) systems rely on millisecond precision with accuracy in microseconds.

Global Positioning Systems (GPS) offer precision time signals to synchronize power system devices; however, several time protocols are available, each with its advantages.

This document illustrates various system architectures to support multiple time protocols, using precision time products from Cyber Sciences, Inc.

STR-100 Satellite Time Reference

STR-IDMIRIG-B Distribution Module

SER-3200 Sequence of Events Recorder

TECH NOTE — SER System Architectures

© 2009 Cyber Sciences, Inc. All rights reserved.2 www.cyber-sciences.com

TN-101 | Sep-2009

System architecture: STR-100/IRIG-B provides precision time reference for IRIG-B devices.

Synchronizing IRIG-B Devices (up to 4)Direct Connection

IRIG-B is a widely-used precision time protocol originated by the US military, and is especially popular among electric utilities. If only a few IRIG-B devices are involved, they can be connected to the BNC con-nector on the side of the STR-100/IRIG-B. 75-ohm coaxial cable is used, or twisted pair cable (via adapter) as shown below.

Synchronizing Devices UsingDCF77 or 1per10

DCF77 is a time protocol that originated in Europe and is used by some Square D® PowerLogicTM power monitoring devices. 1per10 stands for “one pulse per ten seconds” and is used to synchronize the clocks of SepamTM relays, also by Schneider Electric. The base model STR-100 supports both of these time protocols, as shown below.

System architecture: STR-100 provides precision time reference for multiple devices via DCF77 or 1per10.

SYSTEM ARCHITECTURES

Satellite Time ReferenceGPS INTERFACE

PWRSYNCSTAT

DCFCH 1CH 2

DCF OUT

STR-100Satellite Time Reference

Trimble AcutimeTM Gold GPS Antenna (”Smart Antenna”)

DCF77 devices (e.g., PowerLogicTM meters: CM4, CM3 or PM870)

DCF77 or 1per10 devices (e.g., SepamTM relays, series 20, 40, 80)

24Vdc power supply (e.g., PS-24V-15W or PS-24V-50W)

Daisy-chain wiring, Belden 8760 cable or equivalent, 1000 feet (300m) max.

1 to 16 devices

1 to 16 devices

DCF77DCF77 or 1per10

24Vdc

MERLIN GERIN MERLIN GERIN

RS-422 signal, Antenna interface cable: CAB-ACU-xxx xxx = length (50, 100, 200 or 400 feet)

IRIG-B input(modulated)


PWRSYNCSTAT

DCFCH 1CH 2

DCF OUT

STR-100/IRIG-BSatellite Time Reference


24Vdc




1 to 4 devices

IRIG-B (unmodulated)

321 5 6 74 8 C 9 10 11 12 13 14 15 16 C 17 18 19 20 21 22 23 24 C 25 26 27 28 29 30 31 32 C A B A B + - GND

PWRTIME

IN/OUTTRIGGER

OUT

ENTERMENU

10/100 ETHERNET OPTIONS

SER-3200EVENT RECORDER

SHLD

SHLD

SER-3200Event Recorder

other IRIG-B devices (e.g., relays or meters)

3© 2009 Cyber Sciences, Inc. All rights reserved.


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TN-101 | Sep-2009

System architecture: Large number of IRIG-B devices synchronized using STR-100/IRIG-B and IDMs

Synchronizing IRIG-B Devices (> 4)Multi-point Connection

To distribute IRIG-B over long distances or to synchronize many IRIG-B devices, an STR-IDM can be used. An STR-IDM greatly simplifies wiring by distributing the IRIG-B time signal over a multi-point network at higher voltages (24Vdc nominal). Up to 8 STR-IDM modules can be connected to an STR-100/IRIG-B, for a total of 64 IRIG-B devices synchronized from a single STR time reference.

System architecture: multiple STR modules share a single antenna.

Hybrid Systems: Multiple STR-100s Sharing a Single GPS Antenna

It is possible to connect multiple STR-100 Satellite Time Reference modules to a single Trimble Acutime Gold smart antenna. A typical scenario is when two STR models are used to provide different types of time reference outputs required by the application as shown below.


PWRSYNCSTAT

DCFCH 1CH 2

DCF OUT




24Vdc


PWRSYNCSTAT

DCFCH 1CH 2

DCF OUT


1 to 16 devices

(per channel)

DCF77 (or 1per10)STR-100

Satellite Time Reference

Shielded, two-twisted-pair cable, Belden 8723 or equivalent



1 to 4 devices

IRIG-B (unmodulated) Daisy-chain wiring, Belden 8760 cable or equivalent, 1000 feet (300m) max.

321 5 6 74 8 C 9 10 11 12 13 14 15 16 C 17 18 19 20 21 22 23 24 C 25 26 27 28 29 30 31 32 C A B A B + - GND

PWRTIME

IN/OUTTRIGGER

OUT

ENTERMENU



SHLD

SHLD



PWRSYNCSTAT

DCFCH 1CH 2

DCF OUT




24Vdc



321 5 6 74 8 C 9 10 11 12 13 14 15 16 C 17 18 19 20 21 22 23 24 C 25 26 27 28 29 30 31 32 C A B A B + - GND

PWRTIME

IN/OUTTRIGGER

OUT

ENTERMENU



SHLD

SHLD


STR-IDM STR-IDMSTR-IDM


To next STR-IDM

1 to 8 devices


321 5 6 74 8 C 9 10 11 12 13 14 15 16 C 17 18 19 20 21 22 23 24 C 25 26 27 28 29 30 31 32 C A B A B + - GND

PWRTIME

IN/OUTTRIGGER

OUT

ENTERMENU



SHLD

SHLD


1 to 8 devices

STR-IDM

1 to 8 STR-IDM modules per STR



IRIG-B (multi-point unmodulated) + 24Vdc



TN-101 | Sep-2009

System with DCF77, 1per10 and IRIG-B Devices

The drawing below illustrates a system that takes advantage of several Cyber Sciences precision time products. The following time protocols and physical implementations are represented:

● RS-422 signal from a “smart antenna” (GPS antenna/receiver in one) ● DCF77 ● 1per10 (1 pulse every 10 seconds) ● IRIG-B, unmodulated, TTL levels (5Vdc nominal) ● IRIG-B, unmodulated, 24Vdc multi-point, plus 24Vdc control power ● IRIG-B, unmodulated, SER inter-device time sync (over RS-485)

System architecture: STR-100 with DCF77 and 1per10 output, STR-100/IRIG-B with STR-IDM IRIG-B Distribution Modules, plus SER-3200 Sequence of Events Recorders (accepts unmodulated IRIG-B)

STR-IDMSatellite Time Reference

GPS INTERFACEPWRSYNCSTAT

DCFCH 1CH 2

DCF OUT



1 to 16 devices

1 to 16 devices

DCF77

DCF77 (or 1per10)


321 5 6 74 8 C 9 10 11 12 13 14 15 16 C 17 18 19 20 21 22 23 24 C 25 26 27 28 29 30 31 32 C A B A B + - GND

PWRTIME

IN/OUTTRIGGER

OUT

ENTERMENU



SHLD

SHLD 321 5 6 74 8 C 9 10 11 12 13 14 15 16 C 17 18 19 20 21 22 23 24 C 25 26 27 28 29 30 31 32 C A B A B + - G

ND

PWRTIME

IN/OUTTRIGGER

OUT

ENTERMENU



SHLD

SHLD


32 inputs (typical) time sync (SER intra-device, IRIG-B over RS-485)

up to 16devices


PWRSYNCSTAT

DCFCH 1CH 2

DCF OUT



24Vdc


IRIG-B devices (e.g., relays or meters)

STR-IDM IRIG-B (unmodulated)

1 to 8 devices

24Vdc power supply (e.g., PS-24V-15W or

PS-24V-50W)

STR-IDM STR-IDM

IRIG-B (multi-point unmodulated) + 24Vdc

STR-100SER-3200IRIG-B (unmodulated)


To next STR-IDM (up to 8)

5© 2009 Cyber Sciences, Inc. All rights reserved.


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TN-101 | Sep-2009

System architecture: GPS receiver with IRIG-B output and STR-100 with DCF77 and 1per10 output.

Hybrid Systems: GPS Receiver as IRIG-B Source and STR as Protocol Converter for DCF77 and 1per10

If an IRIG-B time source is already available, it may be desirable to use this to synchronize IRIG-B devices,and use an STR-100 as a protocol converter to synchronize DCF77 and/or 1per10 devices. The drawing below illustrates such a scenario, including Cyber Sciences SER-3200 Sequence of Events Recorders.

Depending on the physical arrangement of these components, it may also be desirable to take advantage of the SER-3200 time-sync sub-network using an RS-485 multi-point connection as shown above. An RS-485 multi-point, or daisy-chain, wiring configuration may be more cost-effective than point-to-point, or home run, wiring of the IRIG-B signal to each device.


PWRSYNCSTAT

DCFCH 1CH 2

DCF OUT

STR-100Satellite Time Reference

GPS Antenna



1 to 16 devices

1 to 16 devices

DCF77DCF77 or 1per10


GPS Receiver

IRIG-B (modulated)

321 5 6 74 8 C 9 10 11 12 13 14 15 16 C 17 18 19 20 21 22 23 24 C 25 26 27 28 29 30 31 32 C A B A B + - GND

PWRTIME

IN/OUTTRIGGER

OUT

ENTERMENU



SHLD

SHLD 321 5 6 74 8 C 9 10 11 12 13 14 15 16 C 17 18 19 20 21 22 23 24 C 25 26 27 28 29 30 31 32 C A B A B + - G

ND

PWRTIME

IN/OUTTRIGGER

OUT

ENTERMENU



SHLD

SHLD 321 5 6 74 8 C 9 10 11 12 13 14 15 16 C 17 18 19 20 21 22 23 24 C 25 26 27 28 29 30 31 32 C A B A B + - G

ND

PWRTIME

IN/OUTTRIGGER

OUT

ENTERMENU



SHLD

SHLD

IRIG-B (unmodulated) SER-3200Event Recorder

32 inputs (typical) time sync (SER intra-device, IRIG-B over RS-485)

up to 16devices

SER-3200Event RecorderSER-3200




TN-101 | Sep-2009

Doc. no: TN-101Sep-2009

Cyber Sciences, Inc. USA

SummarySequence of Events Recording (SER) systems are increasingly impor-tant to ensure power system reliability. SER systems are now com-mon in data centers, hospitals, refineries, water treatment plants, and throughout electric utility networks. Due to the different protocols used by electrical manufacturers, various system architectures are possible depending on specific project requirements. This document presented examples of the most cost-effective system architectures and showed typical applications of CSI products.

The choice of time sync protocol is usually dictated by the type of power system devices present. The choice of system architecture for a given project depends on the time protocols used, the number of devices and the physical arrangement of the equipment.

For custom applications not specifically covered in this document, or for help in designing the system architecture that best meets your require-ments, please contact Cyber Sciences.

For More InformationSTR Instruction Bulletin (IB-STR-01)STR/IRIG-B Addendum (IB-STR-02)IDM Instruction Bulletin (IB-IDM-01)SER Instruction Bulletin (IB-SER-01)Tech Note: Multiple STRs Can Share

a Single GPS Antenna (TN-105)

SUMMARY

CABLE RECOMMENDATIONS Selecting the Right CableThe table below summarizes the cable types recommended in this technical note. They are provided only as a guideline. Verify that any cable meets the requirements of your project before ordering materials.

TIME PROTOCOL CABLE SELECTION SUMMARY

Time Protocol Recommended Cable Description

DCF77 Belden 8760 (or equiv.) Shielded, twisted-pair cable, copper, #18 AWG, 300V rms

1per10 (1 pulse every 10 sec.) Belden 8760 (or equiv.) Shielded, twisted-pair cable, copper, #18 AWG, 300V rms

IRIG-B, unmodulated Belden 8760 (or equiv.) Shielded, twisted-pair cable, copper, #18 AWG, 300V rms

IRIG-B, unmodulated, @ 24Vdc + 24Vdc power (to/from STR-IDM) Belden 8770 (or equiv.) Shielded, 3-conductor cable, copper, #18 AWG, 300V rms

IRIG-B, unmodulated, over RS-485 (to/from SER-3200) Belden 9841 (or equiv.) Shielded, twisted-pair cable, copper, #24 AWG, 300V rms

Trimble Acutime Gold smart GPS antenna interface (RS-422)

Trimble Acutime Gold Interface Cable(ACU-CAB-xxx)

Shielded, six-twisted-pair cable (12 conductors), #22 AWG, with 12-pin antenna connector on one end. Available in lengths of 50, 100, 200 and 400 feet.

Antenna Interface Cable between STR-100s when sharing an antenna Belden 8723 (or equiv.) Shielded, two-twisted-pair cable, copper, #22 AWG, 300V rms

ReferencesBrown, PE, Bill, and Mark Kozlowski, “Power System Event Recon-struction Technologies for Modern Data Centers,” Square D Critical Power Competency Center. Aug. 2006. www.criticalpowernow.com.

Dickerson, Bill, P.Eng., Arbiter Systems, Inc. “Time in the Power Indus-try: How and Why We Use It.”

http://www.criticalpowernow.com

TN-101 SER System Architectures

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