Hitachi ATT-20 Installation, Operation, Troubleshooting

SM 6299

1000 Technology Drive, Pittsburgh, PA 15219

645 Russell Street, Batesburg, SC 29006

STS USA Part Numbers

N454052-3901

N454052-3906

ATT-20 Audio Track Transceiver

through

 Troubleshooting

 Installation

 Operation

ATT-20 Audio Track Transceiver

Proprietary Notice

This document and the information contained therein are confidential – the disclosure or other communication, copying, reproduction and any use whatsoever is forbidden without the written authorization of Hitachi Rail STS USA, Inc.

Important Notice

STS USA constantly strives to improve our products and keep our customers apprised of changes in technology. Following the recommendations contained in the attached service manual will provide our customers with optimum operational reliability. The data contained herein purports solely to describe the product, and does not create any warranties.

Within the scope of the attached manual, it is impossible to take into account every eventuality that may arise with technical equipment in service. Please consult an STS USA local sales representative in the event of any irregularities with our product.

STS USA expressly disclaims liability resulting from any improper handling or use of our equipment, even if these instructions contain no specific indication in this respect. We strongly recommend that only approved STS USA spare parts are used as replacements.

the written authorization of Hitachi Rail STS USA, Inc.

1000 Technology Drive, Pittsburgh, PA USA 15219-3120

645 Russell Street, Batesburg, SC 29006

sts.hitachirail.com

ATT-20 Audio Track Transceiver

April 1997

Initial issue

Revised to current template.

resolved.

Revised Figure 1-1 and Figure 6-1 to

Unit part numbers.

March 2019

Hitachi Rail STS Branding

Revision History

REV. DATE NATURE OF REVISION

Updated parts lists and drawings.

1.0 June 2008

2 December 2015

Incorporated ECO EE-1223 (2/00). Miscellaneous minor grammatical changes. Proof read comments

add R14 and label. Revised Table 6-4 and Figure 6-1 for items 126 and 127. Revised Table 6-5

to correct ATT-20

ATT-20 Audio Track Transceiver

Table of Contents

1. GENERAL INFORMATION ............................................................................................................... 1-1

1.1. Introduction ............................................................................................................................... 1-1

1.2. Physical Description ................................................................................................................. 1-1

1.3. Specifications ............................................................................................................................ 1-1

1.3.1. Power Requirements .................................................................................................... 1-1

1.3.2. Transceiver Characteristics .......................................................................................... 1-2

1.3.3. Receiver Characteristics ............................................................................................... 1-2

1.3.4. Miscellaneous ............................................................................................................... 1-3

2. APPLICATION, INSTALLATION, AND ADJUSTMENTS ................................................................ 2-1

2.1. General ..................................................................................................................................... 2-1

2.2. Shunt Mode Track Circuit Application ...................................................................................... 2-1

2.3. Series Mode Track Circuit Application ...................................................................................... 2-2

2.4. Terminal Connections ............................................................................................................... 2-3

2.5. Mounting Requirements ............................................................................................................ 2-3

2.6. General Considerations ............................................................................................................ 2-3

2.7. Shunt Mode Operation .............................................................................................................. 2-4

2.7.1. Shunt Mode Installation ................................................................................................ 2-4

2.7.2. Shunt Mode Adjustment ............................................................................................... 2-5

2.8. Series Mode Operation ............................................................................................................. 2-5

2.8.1. Series Mode Installation ............................................................................................... 2-6

2.8.2. Series Mode Adjustment without Cable Compensating PCB ....................................... 2-6

2.8.3. Series Mode Adjustment with Cable Compensating PCB ............................................ 2-7

2.9. Lightning Protection .................................................................................................................. 2-7

3. FUNCTIONAL DESCRIPTION .......................................................................................................... 3-1

3.1. General ..................................................................................................................................... 3-1

3.2. Shunt Mode Track Circuit ......................................................................................................... 3-1

3.3. Series Mode Track Circuit ........................................................................................................ 3-1

3.4. Detailed Circuit Description ...................................................................................................... 3-1

3.4.1. Transmitter .................................................................................................................... 3-1

3.4.2. Receiver ........................................................................................................................ 3-2

4. FIELD MAINTENANCE ..................................................................................................................... 4-1

4.1. General ..................................................................................................................................... 4-1

4.2. Test Equipment ......................................................................................................................... 4-1

4.3. General Checks ........................................................................................................................ 4-1

4.4. Shunt Mode Checks ................................................................................................................. 4-1

4.5. Series Mode Checks ................................................................................................................. 4-3

5. SHOP MAINTENANCE ..................................................................................................................... 5-1

6. PARTS LISTS .................................................................................................................................... 6-1

6.1. ATT-20 Audio Track Receiver Kits ........................................................................................... 6-1

ATT-20 Audio Track Transceiver

6.2. ATT-20 Audio Track Transceiver Units .................................................................................... 6-1

6.3. ATT-20 Audio Track Receiver Parts List .................................................................................. 6-2

6.4. Cable Compensating PCB Parts List ........................................................................................ 6-5

7. RAIL TEAM AND TECHNICAL SUPPORT ...................................................................................... 7-1

List of Figures

Figure 1-1. ATT-20 Dimensions ......................................................................................................... 1-3

Figure 2-1. Shunt Mode Track Circuit Application .............................................................................. 2-1

Figure 2-2. Series Mode Track Circuit Application ............................................................................. 2-2

Figure 2-3. Lightning Arrester and Surge Ripple Filter for Shunt Mode Application .......................... 2-9

Figure 2-4. Lightning Arrester and Surge Ripple Filter for Series Mode Application ....................... 2-10

Figure 3-1. Transmitter PCB Schematic Diagram .............................................................................. 3-3

Figure 3-2. Receiver PCB Schematic Diagram .................................................................................. 3-5

Figure 4-1. ATT-20 Test Circuit for Shunt Mode Application ............................................................. 4-2

Figure 4-2. ATT-20 Test Circuit for Series Mode Application ............................................................. 4-3

Figure 6-1. ATT-20 Parts Illustration .................................................................................................. 6-4

Figure 6-2. ATT-20 Wiring Diagram ................................................................................................... 6-5

Figure 6-3. Cable Compensating PCB Parts Layout and Schematic Diagram .................................. 6-6

List of Tables

Table 1-1. Adjacent Frequency Rejection ......................................................................................... 1-2

Table 2-1. Terminal Assignments...................................................................................................... 2-3

Table 2-2. Ring-by Parameters for 0.1 Ohm Shunting ...................................................................... 2-5

Table 2-3. Cable Length vs. Frequency ............................................................................................ 2-6

Table 6-1. ATT-20 Unit Kits ............................................................................................................... 6-1

Table 6-2. ATT-20 Unit (Only) ........................................................................................................... 6-1

Table 6-3. Miscellaneous Application Units ...................................................................................... 6-1

Table 6-4. ATT-20 Unit Parts List ...................................................................................................... 6-2

Table 6-5. ATT-20 Part Tabulation .................................................................................................... 6-3

Table 6-6. Cable Compensating PCB Parts List ............................................................................... 6-5

ATT-20 Audio Track Transceiver

1. GENERAL INFORMATION

1.1. Introduction

This manual provides application, installation and maintenance information for the STS USA Audio Track Transceiver, Model ATT-20.

The ATT-20 is a short-range transceiver operating in the audio frequency range of 12 to 20 KHz. The high frequency range was chosen to provide sharp block definition. The ATT-20 can be used in applications such as highway crossings, island circuits, switch lock release and general train detection in non-electrified and DC electrified territories. In most cases, insulated joints are not required and track circuits up to 300 feet in length can be realized. Units are available for operation in either shunt mode or series mode applications.

1.2. Physical Description

The ATT-20 is a single unit transceiver containing separate transmitter and receiver printed circuit boards, mounted on a common chassis. The chassis is housed in a sheet metal box. The top cover of the unit is the faceplate to which Association of American Railroads (AAR) terminal posts are mounted.

1.3. Specifications

1.3.1. Power Requirements

Power Supply Voltage: 9.8 - 15.2 VDC Maximum Ripple: 1 Vpp Load Current: 600 mA. Fuse: 3 / 4 Amp fast blow

ATT-20 Audio Track Transceiver

1.3.2. Transceiver Characteristics

CAUTION

The ATT-20 may be operated from a constant potential rectifier (CPR) supply, batteries floating on a CPR, or an electronically regulated supply. Regardless of the supply used, a surge ripple filter (STS USA N451590-0301) must be used between the supply and the ATT-20 Transceiver.

Shunt Mode Output Voltage: 1.0 Vrms (modulated) into a 5-ohm load Series Mode Output Voltage: 0.25 Vrms (modulated) into a 1-ohm load Available Operating Frequencies: 12.28 KHz, 15.0 KHz, 20 KHz. Carrier Frequency Tolerance: + 0.5 % Modulation Frequency (All Units): 390 Hz + 0.5% Harmonic Output: -30 dB at second harmonic with 12 ohm load in shunt mode 7 ohm shunt mode; 1 ohm series mode

1.3.3. Receiver Characteristics

Sensitivity: 70 mVrms (modulated signal) + 14 mV Input Impedance: 7 ohms shunt mode, 1 ohm series mode Output Voltage: 7.65 VDC into 400 ohms

Table 1-1. Adjacent Frequency Rejection

ATT-20 Frequency

(KHZ)

12.28 15.0 -18.0

15.0

20.0

Adjacent Frequency of

Concern (KHz)

12.28

18.0*

20.0

15.0

18.0*

Rejection of Adjacent

Frequency (dB)

* Of concern where joint detectors are used.

-30.0

-21.0

-27.0

-44.0

-23.0

ATT-20 Audio Track Transceiver

RCV

(REF)

AUDIO TRACK

TRANSCEIVER

MODEL,ATT-20

(REF)

LOWER

6 1/16

2 1/8

RE LAY

(REF)

TL5

TL6

SHUNT

MODE

UNIT

2 1/4 (REF)

PC.NO. SER.NO. FREQ. RE V.

7 5/8

(REF)

BAT TE RY

XMT

4 5/8

(REF)

9 /41

RE LAY VO LTS

TL1

RAISE

(REF)

TL2

TL3

TL4

3B3.0001.01

R14

1.3.4. Miscellaneous

Reverse battery protection: Built-in Operating temperature range: - 40°C to +70°C Maximum block length: 300 ft. shunt mode at 3 ohm/1000 ft. ballast; 150 ft.

series mode at 3 ohms/1000 ft. ballast.

Recommended Relay: PN-150B, 400 ohm coil, (STS USA N322500-

701) Overall Dimensions: Refer to Figure 1-1. Mounting Hole Dimensions: 2¼" x 8½" Weight: 4 lbs., 14 oz. Terminal Connections: AAR

Figure 1-1. ATT-20 Dimensions

ATT-20 Audio Track Transceiver

300 FEET

MAX.

RING-BY

USSP-21

BATTERY

TWISTED PAIR

ATT-2 0

HARD-WIRE SHUNT

USED DURING

SET-UP

3B3.0002.01

2. APPLICATION, INSTALLATION, AND ADJUSTMENTS

2.1. General

This section provides information on the application of the ATT-20, as well as installation and adjustment procedures for the ATT-20 and related equipment. It is also critical that this section be read in its entirety prior to any application considerations.

2.2. Shunt Mode Track Circuit Application

In this application, the transmitter output and receiver input are connected by cable directly to the rails. The connection is made through surge protectors by twisted line pairs as shown in Figure 2-1. The point at which the transmitter wires are connected

defines one end of the track circuit. While the other end of the track circuit is defined by

the receiver connections to the track. The receiver detects the presence of a train by the loss of the audio frequency signal that is shunted away by the train axle.

The shunt mode of operation is defined as a vital application.

Figure 2-1. Shunt Mode Track Circuit Application

ATT-20 Audio Track Transceiver

75 FEET

60 FEET

ADJUSTMENT

SHUNT

“O”

OHM SHUNT

USSP-21

TWISTED PAIR

ATT-20

12V

BATTERY

5 7

2 4 6

T2 T3

C1 2

CABLE COMPENSATING PCB

3B3.0003.

2.3. Series Mode Track Circuit Application

In this application, the transmitter and receiver are wired in sequence via a jumper on the ATT-20 unit. This jumper connects transmitter output terminal 4 to the receiver input terminal 6. The remaining transmitter output lead (terminal 3) and the remaining receiver lead (terminal 5) are twisted as a pair and each is connected to its respective rail (see Figure 2-2). The presence of a train axle across the rails completes the series signal path, thus detecting the approach of a train.

The series mode of operation is a non-vital application.

Figure 2-2. Series Mode Track Circuit Application

ATT-20 Audio Track Transceiver

2.4. Terminal Connections

AAR type terminals are located on the top of the unit for making external connections. Refer to Table 2-1 for terminal assignments.

Table 2-1. Terminal Assignments

Terminal No. Description

1 + Battery

2 - Battery

3 Transmitter Lead

4 Transmitter Lead

5 Receiver Lead

6 Receiver Lead

7 + Relay

8 - Relay

Internal wiring is accessed through a hole with a grommet around it in the faceplate. Also located on the faceplate is an access hole which is intended for setting transmitter gain. This is a simple adjustment and can be accomplished with a screwdriver.

2.5. Mounting Requirements

A convenient mounting bracket, which is an integral part of the case, provides four holes spaced 2-1/4 x 8-1/2 apart to facilitate wall, shelf or rack mounting.

2.6. General Considerations

• Track leads to the transmitter and receiver must be a #9 AWG or heavier twisted pair.

• Power supply must be 9.8 - 15.2 VDC and capable of supplying 1 ampere. A surge ripple filter (STS USA Part No. N451590-0301) must be used between any supply and the ATT-20. Power supply ripples must not exceed 1.0 Vpp.

• Use higher frequency units when less ring-by is desired.

• Provide lightning protection per Section 2.9.

• The relay recommended to be used with ATT-20 is a vital PN-150B, STS USA

No. N322500-701, 400 ohm, plug-in type.

+ 29 hidden pages

Hitachi ATT-20 Installation, Operation, Troubleshooting

Specifications and Main Features

Frequently Asked Questions

User Manual

1. GENERAL INFORMATION

1.1. Introduction

1.2. Physical Description

1.3. Specifications

1.3.1. Power Requirements

1.3.2. Transceiver Characteristics

1.3.3. Receiver Characteristics

1.3.4. Miscellaneous

2. APPLICATION, INSTALLATION, AND ADJUSTMENTS

2.1. General

2.2. Shunt Mode Track Circuit Application

2.3. Series Mode Track Circuit Application

2.4. Terminal Connections

2.5. Mounting Requirements

2.6. General Considerations