SM-0506

SM-0506
QESCRIPTION OF
TIME CODE CONTROL SYSTEM
TYPE L- FORM 506
For
MULTIPLE LINE APPLICATION
16 STEPS-35 STATION BASIS
Using
BIASED POLAR LINE AND STARTING RELAYS
IMPULSE STARTING ACTION
GRESSIVE DELIVERY OF CONTROL FUNCTIONS
POLAR STICK FUNCTION CONTROL RELAYS
MANUAL
No. 506
JUNE, 1942
UNION SWITCH & SIGNAL CO.
»
»
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PENNSYLVANIA
PRINTED IN U. S. A.
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TABLE OF CONTENTS
PART I
GENERAL DISCUSSION
Purpose .................................................. .
Scheme .................................................. .
Capacity ................................................. .
DESCRIPTION OF EQUIPMENT
Control Machine ......................................... .
Automatic Train Graph ................................... .
Office Line-Coding and Storage Groups ...................... .
Field Equipment .......................................... .
Function Control Relays ................................... .
SPECIAL FEATURES
Composite Codes ......................................... .
Multiple Storages ......................................... .
Simultaneous Storages ..................................... .
Line Check and Lock Action .............................. .
Line Circuit Action ....................................... .
Control and Indication Tell-Tale Meter ..................... ;
Bell Indication-Track .................................... ,
Repeat Action-Knockdown .............................. .
Relay Operations-Minimum .................... : ........ .
Broken Line Circuit ................................. ·...... .
Permanent Short on the Line Circuit ........................ .
Line Circuit Combinations ................................ .
PLAN OF OPERATION
Control Code ...................... ·................... .
Indication Code ....................................... .
·2
PART 11
GENERAL OUTLINE OF OPERATION
Line Circuit ....... ; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page
27
Starting Relays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
Master Relay..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
Line Pole-Changer Relays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
Counting Chain ............................... : . . . . . . . . . . .
34
Chain Repeat Relay ....................................... -:
35
Timing Relay Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
36
Station Registry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38
Code Preference Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40
Function Registry ............... : . . . . . . . . . . . . . . . . . . . . . . . . . .
44
RELAY NOMENCLATURE AND FUNCTIONS
Line Relay, etc.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
48
DETAIL CIRCUITS FOR CODE ACTION
Office Transmitting Control Code . . . . . . . . . . . . . . . . . . . . . . . . . . .
54
Field Station 234 Receiving Control Code. . . . . . . . . . . . . . . . . . . .
62
Wayside Circuits ........................................... · 68
Field Station Starting Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
69
Field Station Transmitting Indication Code . . . . . . . . . . . . . . . . . . .
70
Offi_ce Receiving Indication Code. . . . . . . . . . . . . . . . . . . . . . . . . . . .
78
Action at Field Stations Locked Out By Indication Codes ..... ·. .
88
Open or Shorted Line Circuit ........................ ,. : . . . . .
88
Irregular Operations Due to Equipment Trouble................
89
LINE CIRCUIT COMBINATIONS
· Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
90
~
!!""
..j::;..
Front View of a Typical Desk Type Code Control Machine equipped
with an Automatic Train Graph. Capacity 60 Panels
TIME CODE CONTR.OL SYSTEM
TYPE L-FORM 506
PART I
GENERAL 01scuss1·0N
PURPOSE
The purpose of t_~e Code Control System is to provide
a means whereby signal systems can be controlled and
operated from a centralized~ location which may be re~
motely located from the signal system.
Broadly, a Code Control System provides,
FIRST-Means at the control point for individual con:
trol and operation of switch and signal functions for
the control and routing of traffic.
SECOND-A complete set of lamps for indicating to
the control operator the movements and positions
of the controlled functions.
THIRD-Traffic information to the control operator in
the form of lamp indications on a track ·model show~
ing the presence and location of trains in the con~
trolled territory.
FOURTH-A train graph for automatically recording
all train movements through the controlfed territory.
(Optional).
SCHEME
The Time Code Control System is a·n all~relay code
system designed on the time element principle. It·requires
a single line circuit consisting of but two wires extending
from the control point to the distant ends of the controlled
5
/
territory. The line <:ircuit is normalty energized from a
battery located at the control point.
The Time Code Control System is designed to be
directly applicable to the control of switch and signal
functions of any type of track layout, regardless of whether
the functions are individual and widely spaced, as on
single :track, or closely grouped as in two, three or four
track interlockings, or in different combinations.
, In the Time Code Control System the codes are com.posed of a series of short and long impulses. Codes are
given individual character by the sequence in which the
short and long impulses are arranged. The circuits have
been designed so" that both the open and closed line im..
pulses perform useful functions. The time required to
transmit a control or indication code is approximately
4 seconds.
Each control code consists of 16 impulses. The first
impulse (always long) ts used for line check and lock pur..
· poses. The next 7 impulses (3 of which are long and 4
short) are used for station selection. The next 7 impulses
(any of which may be short or long depending upon the
information to be transmitted) are used for function con.trols. The last or 16th impulse (always long) is used for
resetting ali apparatus to the normal condition.
Each indication code :cbnsists of 16 impulses. The
first (always short) is used for line check' and lock pur..
poses. The next 7 impulses (3 of which are 'long. and 4
short) are used for station selection. The next 7 impulses
(any of which may be short or long depending upon the
.information to be transmitt~d) are used for function indi..
cations. The last or 16th impulse (always long) is used
fo,r operating the indication stick relays in accordance with
6
the information transmitted on the preceding 7 impulses
and for resetting all apparatus to the normal condition.
CAPACITY
The Time Code Control System is designed to handle
a maximum of 35 stations, each station being capable of(a) Controlling seven two.-position functions.
(b) Indicating seven two.-position functions.
(Three.-position functions, such as switches and signals,
require the use of two two.-position function assignments
in combination).
When the controlled territory includes more than 35
stations, additional line circuits are required. It is more
economical to locate the control point (office) within the
controlled territory arid have the ~tations approximately
evenly divided on the two lines, one in each direction from
the control point. With this arrangement it is apparent
that 70 stations may be controlled from one control point.
Branch lines can be added to any line circuit at any point.
However, the maximum number of stations that can thus
be controlled is limited to 25 stations for each complete line
circuit when a branch line is involved. Methods have
been developed to employ carrier frequencies for the re.mote control of entire line circuits. This permits more
than 35 stations on one pair of wires and permits greater
latitude it1 the actual location of the office.
Table I shows the usual allocation of the consecutive
steps of both control and indication codes. Steps 9 to 15
can be assigned to other function combinations if desired.
Table II shows the 35 possible station code combinations
obtainable with the seven (2nd to 8th) impulses used for
station selection. (The station code number refers to the .
long impulses contained in that station code combination).
7
r
TABLE I
ALLOCATION OF CONSECUTIVE CODE STEPS
CONTROL CODE
INDICATION CODE
1 long -Line check and
Lockout.
2 to 8 -(For Station Selection See Table
II). Each station
code combination has three
long and four
short impulses.
9 long -Normal Switch.
10 short-(Special cofitrol
if i m p u 1 s e is
made long).
11 long -Reverse Switch.
1 short-Line check and
Lockout.
2 to 8 -(For Station Selection See Table
II). Same as the
station co'mbination for the con- trol code.
9 long -Switch-,Normal.
10 short-Track clear.
10 long -Track occupied.
11 long-'Switch Reverse.
12 short:-Approach clear.
12 long -Approach occupied.
13 16ng -,Left signal clear.
14 short-Power on.
14 long -Power off.
15 long -Right signal s:lear.
9 & 11 short-Switch open.
13 & 15 short-Signals at
stop.
13 & 15 long-Time re·:,
lease ·operating.
16 long -Indication stick
relays operated
on selected panel.
Code apparatus
reset to normal
condition.
12 sho'tt-(Special control
if i m p u 1 s e is
made long).
13 long -Clear left signal.
14 long -Clear call-on
signal.
15 long -Clear right signal.
13 & 15 short-Signals to
stop.
14 short-Call-on signal to
stop.
16 long -Reset code apparatus to normal
condition.
8
TABLE II
THE 35 ST A TION CODE COMBINATIONS
STATION
CODE
NUMBER
234
2~5
236
237
238
245
246
247
248
256
257
258
267
268
278
345
346
347
348
356
357
358
367
368
378
456
457
458
467
468
478
~67
568
578
678
STATION
2nd.
--
3rd.
4th.
CODE IMPULSES
5th.
6th.
7th.
8th.
- - - - -- - - - -- - .- -- -- - -- - - - - -- - - - - - - - - - - - - -- -- -- -- -- -- --- -- -- -- -- -- --- -- - -- - -- -- - -- - -- - - - - - - - - - - - - - -- - - - - - - - - - --- -- --- --- --- --- ---- -- -- -- -- -- ---- --- --- --- --- --- .--·
-- -- -- -- -- -- -- - - - - - -- - -- -- - - --
-
- 1 .,
'
'
Note: .:..__ Denotes "long" impulse -
9
- .
Denotes "short" impulse
A Typical Code Control Machine without a Desk or
an Automatic Train Graph. Capacity 15 Panels
10
DESCRIPTION OF EQUIPMENT
CONTROL MACHINE
The control machine is constructed of steel. It is ap ..
proximately 54 inches high and 16 inches deep. At the
option of the customer, the machine can be furnished with
or without a shelf or desk top.
The machine is composed of standard sections either
2,U or 5 feet in length. These sections are constructed
so that, if the size of the installation requires, a number
of these sections can be placed end to end or in a confi.gur..
ation, such as rectangular or hexagonal shape, for more
ready manipulation. . With either of the above arrange..
ments of sections, the appearance is that of one integral·
machine.
On the front of the machine above the desk top are
located the control levers, starting push buttons and indi..
cation lamps for both train movements and signal func ..
· tions. This section of the machine consists of a number
of similar panels each assigned to a particular field station.·
These similar panels are uniformly spaced (2 inch centers)
throughout the length of the machine.
Each standard panel consists of a two ..position switch
lever with two indication lamps directly assodated; a three..
position signal lever with three indication lamps directly
associated; a two ..position push button (stick type) for th~
control of a "calling..on" signal or for the control of the
"stick" feature in connection with standard signaling;
and a two ..position push button (spring return type) for
initiating code action. Other special controls are con..
veniently located. If certain functions are controlled by
direct wire, the spacing of the levers will depend upon the
number of contacts required on the levers.
11
rThe track indication lamps are located in a track dia..
gram extending across the panel above the control levers.
Bells for audibly announcing train movements, power off,
etc. can be provided as desired.
On one end of the front panel immediately above the
desk top are two two.-position buttons. One of these but..
tons (spring return type) is used for cancelling control
code storages. The other (stick type) is used for cutting
in track indications 9n the approach indication bell cir.cuit so as to announce audibly track occupancy.
AUTOMATIC TRAIN GRAPH
The control machine may optionally be equipped with
an Automatic Train Graph for making a permanent rec-ord of train movements. This graphic recorder is mounted
horizontally below a glass on the desk top and operates
a continuous chart which advances at the rate of three
inches per hour. The graph paper is furnished in two
standard widths, 16 ;1 and 23 inches. Each roll contains
about 200 feet of paper which is sufficient for one month.
of service. The paper is parallel lined and printed for
direct reading_ of time. An individual pen is provided for
recorciing the track relay operations at each point desired
in the territory. Each Automatic Train Graph is capable
of recording up to 40 individual track sections with the
16,Y2' inch paper and up to 57 track sections with the 23
inch paper.
12
Automatic.Train Graph
95
M.P.l
,
STOCKTON
100
IOS
I
I
'-'
'--'
ARM·
LOOI
'-'
CASTLE
110
IIS
I
'--'
\..J
ACAMPO
FOREST
LAKE
STRONG
I
r:\
GALT
\..J
NEED
7P.M
~
p
SET OUT
CREW
t ..
(STATION STOPl
Xl658
6P.M.
-
--
SP.M.
X32S8E
W.M
-
-
-
-
~
-~- -
NON-STOP
MEET.S
4P.M.
Reproduction of a portion of an actual Train Graph Chart
13
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OFFICE LINE-CODING AND STORAGE GROUPS
At the office, the relays are divided into two groups:
Office Line..Coding group and Office Storage group.
The line..coding group includes all relays directly as ..
sociated with the line circuit, such as the line and the
transmitti11g relays; all relays the function of which is to
generate the stepping action for code progression of out..
going codes and to follow this action for incoming codes;
all relays involved in the line checking and locking action
and in the timing of the impulses; and all relays that inter... ,,,
pret and store the code for delivery to the storage units at
the conclusion of each code action. This group of relays is
Rear View of a Control Machine showing Office Line,Coding Units
and Office Storage Units
' 14
housed in an ·individual sheet meta1 'case. All connections between this unit and the line or between this unit
and the storage units are established by a plug connector
~ on the top of the unit. The unit is mounted in the back
of the control machine in such a way th~t it can be readily
replaced.
The office storage group of relays includes the relays
that have to do with initiating control code action; the
relays that determine the station channel for outgoing and
inC:oming codes; the indication stick relays· that are operated by indication codes received through the line coding
~ unit; and the relays that deliver the information that is
stored in the line-coding unit during the indication code
to the final indication stick relays at the conclusion of the
code. The number of station channel relays varies for
installations of different size; only enough being used to
handle the number of stations that the installation requires. The number of indication stick relays will vary
for installations of different size; a similar group of relays
being required for each station or panel of the installation,
and only such relays used as are assigned to indications
in such panels.
This group of relays is housed in a number of indi. vidual sheet metal cases, each housing the relays associated
with a group of stations or panels. The number of individual storage units required depends upon the size of the
installation. These units are mounted in the back of the
control machine. In general, each horizontal. row ·of relays in the storage unit is associated with one panel or
station. Because these units vary in make-up to suit the
I location requirements, they are not made plug.-connected.
Terminal boards are provided for terminating line and
battery circuits and such other circuits as are required by
the installation layout.
15
Office Line Coding Unit
Field Line~Coding~Storage Group
Field Pyramid Unit
Field Storage Group
16
~-
FIELD EQUIPMENT
The field equipment-is divided into the Field Line. .Cod. .
ing group and the Field Storage group. The functions of
the field line. . coding group are similar to the .functions of
the office line. .coding group. The functions of the field
storage group are similar to the functions· of the office
storage group. The field storage group, however, has the
capacity to handle the functions of one station only; i.e.,
seven two . .position controls and seven two . .position indi. .
cations.·
The field line. .coding group of relays and one field
storage group of relays, except the line and starting relays,
are housed in a single sheet metal unit, known as the Field
Line. . Coding. .Storage unit. The Line and Starting relays
are mounted on an adjacent rack. The combination iS'
known as the field line. . coding. .storage group. All of these
groups are identical throughout an installation regardless
of the size or character of the signal system controlled.
All connections, many of which are of necessity dif. .
ferent for different locations, are made on plug connectors
which are wired as integral parts of the permanent loca. .
tion wiring. The cas·e units disconnect from these plug
connectors as integral units, whereas the line and starting
relays are individually plug. . connected.
Ordinarily, in single track installations, only the line. .
coding. .storage group will be required at each location
(end of passing siding). The equipment, however, has
been designed so that where several switches and. signals
are to be controlled from a single location (such as in a
small. interlocking), additional storage groups of relays
may be connected to the line. . coding. .storage group, in
multiple with the storage portion included in that group.
These additional storage groups are identical with the
17 .
storage portion of the line-coding-storage group and individually housed in sheet metal ca§es and racks.
· The number of stations or storage groups that can be
naturally controlled by any one field line-coding-storage group depends upon the code combination for the particular group in question. The maximum number of
stations that can thus be controlled is as follows:
Line-coding-storage
Groups
Stations
Each
1
2
3
5
4
4
5
3
8
3
2
2
9
Storage groups Total
· Added
Stations
8
1
0
5
5
Total number of stations ............ 35
4
1
When a field location layout requires more stations
than can be naturally controlled by the field line-codingstorage group, with added storage groups, as tabulated
above, a field pyramid unit can be added to the equipment
to further expand the number of stations that can be con-·
trolled. Such pyramid units are variable in size and can
be designed to expand the station capacity of one field
line-coding-storage group to the full 35 station complement.
Each field line-coding-storage unit is pro.vided with
four separate plug connectors on the top 'of the unit.
These are used for line, battery, code-setting, and wayside
equipment connections, and for connecting additional
storage units to the line-coding-storage unit.
Each field storage unit is provided with two separate
plug connectors. These are used for battery and wayside
18
equipment connections, and for connecting the storage
unit to the line-coding-storage unit.
Each field pyramid unit is provided with two or more
separate plug connectors. These are used for connections
between the field line-coding-storage· unit and the additional storage units.
Each field line relay and starting relay is individually
plug-connected on mounting racks. The connectors are
wired to terminals provided on these racks.
FUNCTION CONTROL RELAYS
The field relays which are operated by control codes
and which control the positions of the wayside functions
are of the "KP" type polar stick relays. These relays are
individually plug-connected on mounting racks. The connectors are wired to standard terminals provided on these
racks. Standard signal circuits are connected through
these terminals.
Function Controls
All controls are respons~ve to the positions of the re,
spective operating levers, provided the wayside circuits
Twin Unit
Single Unit
Final Stick Relays
19
permit such response. The levers are manually positioned,
then the control code is started by the operation of an
associated starting push button.
Function Indications
All indications are responsive to changes of the stand..
ard wayside equipment. Normally one indication lamp
for each switch lever and one for each signal lever is
lighted. A normally "dark" track model is provided, a
lighted lamp designating an occupied track section.
When a control code is transmitted, no change takes
place in the associated indication lamps until the involved
functions change position in the field and return the in..
dication by code.
.
20
SPECIAL FEATURES
COMPOSITE CODES
The system is designed .so that the code characters for
positioning all of the controlled functions associated with
a particular station are included in each control code for
that station. Likewise the code characters representing
the positions of all indicated functions associated with a
particular station are included in each indication code
from that station.
MULTIPLE STORAGES
Multiple control code storages may be made and the
· codes will be transmitted one at a time in a sequence de.pending upon the "code numbers" of the stations for
which the storages were made; the station with the lowest
code number being first, the next lowest second, etc. This
same action js true in case of multiple storages at any one
:field location. However, when two or more :field locations
obtain multiple storages and are coding at the same time,
the one nearest the office is assigned the preference code
numbers. The order of these indication code preference
numbers is outlined in a later portion of this Manual.
SIMULTANEOUS STORAGES
The relays in the units are timed so that in c,ase control
code storages and indication code storages are made at the
safl?.e tifne, the control codes will take preferehce;. that is,
all the control codes that were stored will be tr.ansmitted
first and then the indication codes will be transmitted.
Simultaneous storages at :field locations generally will be
tndicated in accordance with their geographical location,
the location nearest the office indicating first.
21
LINE CHECK AND LOCK ACTION
The line ·check and lock action is such that it will permit only one station to transmit at a time. The line check
and lock action also insures that all stations will be in
readiness to receive a code before any station can start,·
to transmit a code.
LINE CIRCUIT ACTION
The line circuit serves as a means of relaying information from the transmitting station to the receiving
station. It includes a line relay and associated controlling
contacts at each location, connected in parallel to a twowire line circuit.
The line circuit is normally energized. When control
codes are transmitted, the line circuit is deenergized and
energized with normal polarity, producing pulses of line
current. All line relays follow these pulses. When indication codes are transmitted, tp.e line polarity is rev~rsed
so that the line -i;elays at only the office and transmitting
field station follow the impulses, which are produced by
alternate shunting of the line to increase and removal of
the shunt from the line to decrease the line current in accordance with the code being transmitted. ·
CONTROL AND INDICATION TELL-TALE METER
A line milliammeter is provided in the panel of the _
office control machine to indicate coding on rhe line. The
direction of the pointer deflection will indicate ~hether
the code is a control or an indication.
BELL INDICATION-TRACK
A single stroke bell is provided for announcing the
entrance of all trains into any given portion of the terri~
22
tory desired.~ Frequently audible indications are desired
only for announcing the "approach" of trains. Accordingly a positive two-:position push button is provided to
cut out the audible indications for the "OS" track sections.
REPEAT ACTION-KNOCKDOWN
Due to the fact that the circuits which initiate code
action are not broken -until completion of the particular ·
code in question, it is obvious _that certain types of trouble
would produce automatic repeats indefinitely until the
code initiation circuits are broken. Accordingly a twoposition knock-down button has been provided on the
control cabinet wherehv. all control code storages may be
cancelled and the repeat action stopped. In order to take
care of this repeat action at a field station a thermal relay
is provided.
RELAY OPERATIONS-MINIMUM
The circuits have been designed so that the coding
action of the relays at the different stations will progress
only so long as it performs useful functions. On control
codes the coding groups of relays at the several field sta~ tions op~ate only during the station selecting impulses.
During the remainder of the code impulses, coding action
at all field stations other than the one selected 'performs
nC? useful function and therefore does not progr_ess. On
indication codes only the relays involved in line check
and lock ·action operate at all stations. The coding and
storage groups of relays operate only at the two stations
involved_ in the code; namely,. the field or transmitting
statiop. and the office or receiving station.
23
BROKEN LINE CIRCUIT
In case the line circuit becomes broken, the code system
will function normally between the office and the point of
break.
PERMANENT SHORT ON THE LINE CIRCUIT
Being a multiple connected line scheme, a permanent
short on the line circuit m~y render. some or ·all of the
field locations inoperative.
LINE CIRCUIT COMBINATIONS
The line circuit used as a channel for the code system
may be equipped with suitable adjuncts so that the same
pair of wires may be used for telephones,I telegraph, tele..
phone selector control, and carrier frequency circuits.
24
PLAN OF OPERATION
CONTROL CODE
Operating the starting button of any panel picks up an
associated starting relay, closing circuits which start. the
transmission of a code and determin~ the character of the
impulses to be transmitted. When once started, the transmitting station runs through- automatically to the end of
the code. The line relays at the office and each field
station operate ·counting chain relays on. each impulse and
at the selected station the registry relays in addition on
each long impulse. The function controls at the selected
station only are -registered immediately following the operation of t~ese registry relays. The registering 9f the function cop.trols operates the standard wayside relays at that
station, and as soon as the station operations are completed, starting circuits for an indication code are pro_vided.
INDICATION CODE
Operating any starting circuit at a field location drops
its starting relay, closing circuits which start the transmission of a code and determine the character of the impulses to be tran.smitted. At the sending station and the
office, but at no other stations, the line relays operate
counting chain relays on each impulse and registry relays
in addition on each long impulse. Upon completion of
the code at the office, the indication stick relays of the
particular station indicating are positioned to agree with
the position of the field functions as reported by the code.
Upon completion of the code at the field station, the
starting circuits which initiated the code are reset.
A detailed description of the code action is given in
the following pages. Circuit diagrams are included at the
back of this Manual.
25
26
PART II
GENERAL OUTLINE OF OPERATION
The accompanying circuit sketches are for the purpose
of illustrati1,1g the principles of the various code actions.
In some instances,. where it is desirable for clearness or
simplicity, these sketches are somewhat different than
. the actual circuits.
·
Before studying the detailed operation of the circuits,
it is desirable to have an understanding of the general
scheme of operation of the system. With this in mind,
the system can be broken into a few major operating parts,
· sut::h as the line circuit, transmitting group, counting chain
group, timing relay group, station registry, and function
registry. These parts will be discussed in the order named.
LINE CIRCUIT
The line circuit serves as the means of relaying infor.matio~ from the transmitting station to the receiving sta..
tion. It includes a line relay located at each station and a
group of contacts controlling this relay.
The office line relay (R) is of the polar stick type; that
is, its armature changes position only in response to
changes in the direction of current through the coil.
Deenergization of the relay does not affect the armature
position.
The field line relays (R) are of the biased polar. type;
that is, they close their normal contacts when energy flows
through the coil from the positive to the negative terminals
and return to their reverse contacts if the current is inter..
rupted or reversed.
The normal (non.-coding) condition of the multiple
line circuit is shown in Fig. 1. The normal contacts of the
27.
office line relay are closed, . although no · current flows
through the coil.. The normal contacts of the :field line
relays also are closed, the relays being in this position
· whenever line wire Ll is positive.
L1
L2
OFFICE
I
LINE
CIRCUIT
Fig. 1
In the normal condition, all stations, office and field,
are in the receiving position. Each line.-coding unit has a
master relay (M) which, when picked up, converts that
unit into a transmitter.
When the office sends a control code, the offic~ T relay
opens and closes the line battery circuit with normal
polarity to operate all field line relays, and at the same
. time operates the office line relay (R) throug~ a local cir.cuit controlling No. 2 coil. (To prevent any interference
in the No. 1 coil as a result of current changes in the im..
pulse transformer, the office M relay opens the No. 1 coil
circuit. The M relay also shunts the secondary winding
of the transformer, which reduces the transformer in.ductance. This results in less inductive load to be opened
and closed by the transmitting contacts).
28
At the start of an indication code from one station,
the field M relay picks up, reversing the polarity of its R
relay and shunting the line. This shunt drops all R relays
more distant from the office and causes an increase of current through the primary of the impulse transformer. The
current induced in the secondary of the transformer flows
through the No. 1 coil of the office line relay, moving the
armature to close the reverse contacts. A circuit through
a reverse contact picks up the pole changer (PC) relay,
which pole changes the line circuit, making Ll negative.
With Ll negative all field line relays which were not
dropped by the shunt on the line are forced to close their
reverse contacts, and the only field line relay which can
operate during the remainder of the code is the R relay at
the 'transmitting station, the control of which was pole
changed by the pick up of its M relay. At all other locations the R relay remains reversed throughout the code
and no other relay actions take place.
Indication code impulses are produced by the transmitting station T relay alternately shunting the line and
then removing this shunt. The line relay at the transmitting station releases and picks up in response; to this
action. At the same time the current passlng through the
primary winding of the impulse transformer at the office
increases and decreases. These current changes produce
corresponding positive or negative pulses in the transformer secondary, which flow through the No. 1 :~oil of the
office line relay, causing it to close the normal ot ~everse
contacts alternately. At the conclusion of an indication
code the line polarity is restored to normal (Ll positive),
and all line relays are picked up to close their normal contacts.
Only one unit at a time can complete the transmission
of a code. If the office and one or more field stations start
29
transmitting at the same time, the office holds the line open
on the first step long enough to drop out all field stations
attempting to transmit, and thus the office takes preference.
If two or more field stations start transmitting at the same
time, the station having the preference code number com..
pletes. All other stations drop out on the step at which
their code setting disagrees with the preference code. A
discussion of how code preference is obtained and a list
of the code sequence is covered later in this description.
STARTING RELAYS
When a function changes in position, a relay is oper..
ated to start coding action. Since functions may change
at more than one station simultaneously, and only one
station can transmit a. code at a given time, the function
changes at stations other than the one which is transmit..
ting must be stored and transmitted to the line later.
In the office a spring..return starting push button is pro..
vided for each lever panel to start control codes. A
momentary depression of this push button picks up a
starting relay ST·, storing this action until the selected
panel sends its control code, shown by Fig. 2.
ST
c~
~8
e.......:..
OFFICE
PB
-------,.;..,...e-<B
TO PICKUP M
MSP.------t
e......:..
~
LWAYSIDE
RELAYS
FIELD
FUNCTION
Fig. 2
30
In the field a normally energized Biased Polar starting
relay ST sticks in the normal position over a front or a
back contact of the function indicating relays, all in series.
When one of these relays changes in position, the stick
circuit is momentarily deenergized while the relay contacts
are moving from front to back, or vice versa (See Fig. 2).
During this impulse. of deenergization the ST relay reverses
and opens its stick contact. The ST relay then remains
reversed until that station sends its indication code, at
which time it is returned automatically to its normal posi..
tion.
The circuits are so arranged that if a function changes
position while the station to which it is assigned is coding,
the change will again reverse the ST relay and tran~mit a
second code to include the functional change.
MASTER RELAY
Normally all stations are in the receiving condition.
When there is no coding on the line and alt apparatus is
reset to the normal condition, each station has an equal
chance to start code transmission. When this condition
is obtained, the starting relay ST picks up a master relay
M which changes that station from a receiver into a trans ..
mitter (See Fig. 3). This relay rem~ins up· throughout the
code and is released when the last counting chain relay 16
picks up, ·which determines that the code has completed.
If several stations start transmission at the sam~ -time, all
but one station are eliminated by a ~ode preference ~ction,
Fig. 3
31
r
'
described later. At the inferior station a code disagree..
ment relay CD picks up, which drops out the M relay and
eliminates that station as a transmitter.
LINE POLECHANGER RELAYS
The line circuit is energized by one polarity normally.
When an indication code starts transmission, a pole..
changer relay PC in the.office picks up to reverse the line
polarity and eliminate all. field stations that are not in a
transmitting condition. This relay is picked up in response
to the office line relay R being operated to the reverse
position (See Fig. 4). It then remains up throughout the
indication code and is released when counting chain relay
16 picks up, which determines that the code has co1npleted.
Shou~d an indication code start simultaneously with a
control code, the control code is given preference and the
picking up of relay M prevents the picking up of relay PC.
PCP
R
--CJ--
.
BLX-C)------
Fig. 4
The PC relay has a repeater PCP~ During·the pick up
or release action of the two relays, a holding circuit is
established for the office line relay to hold it ii:'i position
while the polarity of the line circuit is being changed.
TRANSMITTER
The initiation of a code operates the starting relay
(ST}, which energizes relay M to convert that station into
32
.
)
a transmitter. The character of each transmitted impulse
is determined by the interval of time during which the T
relay is either picked up or released (See Fig. 5).
The T relay is alternately picked up and released by the/
odd numbered counting relays l~J-5 ..7 to make short im..
pulses. When selection requires that an odd numbered
pulse is to be long, battery is applied to the circuit for
sticking: T up, and Tis stuck up until lL and LP release.
This adds the release time of two slow..release relays to the
normal short open impulse, changing it in length from
about to second to about f second.
000 NUMBERED
CHAIN RELAYS
"
Jc1RCUIT TO STICK •'T''up
--\roR LONG ODO IMPULSES
EVEN NUMBERED
CHAIN RELAYS
l.t
,, ,,
TO STATION
SELECTION
RELAYS?_
---1.;...-<s
TO LEVERS
OR f"UNCTION
RELAYS
t
CIRCUIT TO STICK T DOWN
- - - - - - ~ O R LONG EVEN IMPULSES - - - ~ B
Fig. 5
When it is desired to make an even numbered pulse
long, relay T must be held down. This is accomplished
by a circuit sticking T down. Even though battery is ap ..
plied to the pick..up circHit of T (right coil lead), it cannot
pick up if battery is also applied to the hold down circuit
(left coil lead), the relay being short circuited until 2L and
LP release. This adds the release time of 2 slow release
relays to the normal short closed impulse, changing it in
length from about lo second to about f ·second. The
function of resistance R 4..5 is to limit the current when
battery is applied to the left coil lead of T.
33
(Figure 5 illustrates the principle of the transmitter
circuit, but the actual circuits as used in the sy$tems ·are
varied somewhat in order to obtain certain check features.
For instance, during the station selection portion of the
code, instead of terminating a long impulse by opening
the T stick circuit when the timing relays release, the timing relays select a pyramid relay, and the pyramid relay
operation opens the T relay stick circuit. On the first
step of an indication code, T is held energized until LB
picks up).
All codes are made up of long and' short impulses.
The difference in codes is determined by the order in which
the short and long characters are combined. One complete
code, either control or indication, is made up of 16 impulses.
COUNTING CHAIN
The function of the counting chain is literally to count
the impulses which are received by the R relay.
The principle of the counting chain may be seen by
referring to Fig. 6. The position of the relays on the 4th
impulse is shown with relay 4 stuck up over the normal
contact of R. The next operation is the reversing of relay
R at the beginning of the 5th impulse. This does two
things: First, removes battery from. the stick circuit of
relay 4; second, applies battery to relay 5 over~ back contact of relay 3 and a front contact of relay 4. 'Relay 4 will
be slow in releasing until relay 5 picks up, due td a circuit
over the back contact of relay 5 through rectifier 8. How-ever, as soon as 5 picks up, the rectifier snub is cut off of
relay 4, and it drops immediately. It is thus seen that relay
4 is made slow-acting until it has served its purpose, after
which it is released immediately.
34
c
8
R
.
3
S
~·~ - i 1
t _--_::i_-r_·LJ::=
5r-__::}_
2~c
4~c
Fig. 6
The next operation is that of relay R moving to the
normal position at the beginning of the 6th impulse. This
removes battery from relay 5, and applies it to relay 6 over
a back contact of relay 4 and a front contact of relay 5.
, Relay 5 is made slow releasing by rectifier 7 until such
. time as 6 picks up, at which time 5 is released immediately.
All counting chain action is similar to that described
above, the actual circuits being varied somewhat to obtain
desired operations.
Chain relays 1 to 7 operate twice each code at the
office and at the selected station. Relay 8 operates during
the middle of code and relay 16 at the end of code. Relay
1 is picked up the first time over LBP down and second
time over CR up. Thus, the second time over the chain,
relay 1 operates on the 9th impulse, 2 on the 10th, 3 on
· the 11th, etc.
CHAIN REPEAT RELAY
Relay CR is used to differentiate between the two
halves of a code. The CR relay picks up on the 8th step
at the selected station only and remains picked up for the
secorid half of t4e code. (See Fig. 7). The CR relays re..
main down at all stations except the one selected, so when
35
r
/
CR
c--c:::i-,-...-~---------.~8
~
LBP
.:..--
. ------e.-..:e>-eo...:,
.Fig. 7
control codes are being received the chains cease operation
after the 8th step at all except the selected station.
TIMING RELAY GROUP
The retardation time of the Style L code relay is ob..
tained by connecting a rectifier across the coil of the relay.
The "square armature" relay has a more complete mag..
netic circuit than the "round armature" relay. This makes
available a longer release time, so for this reason the
"square armature" relays are used for code impulse timing.
This relay is also adjustable.
c
LB
c
sr-e-..!
Fig. 8
-
Referring to Fig. 8, it will be noted that when LB relay
contact is closed, current flows in the LBP relay circuit the
same as if the rectifier were not present. However, when
LB contact opens, the induced current in the LBP coil can
flow through the rectifier, as shown by the small arrows,
and gradually decreases. This current delays the decay ·
of magnetic flux, thus requiring a longer p~riod of time
to release. (A rectifier snub also offers contact protection
against arcing).
·
During code action, the slow acting relays are ener..
gized as shown in Fig. 9. Relays lL and 2L bridge the
time of a short impulse ( lo second), but will not bridge a
long impulse, dropping out after about ! second. It can
36
Fig. 9
thus be seen that if R stays normal for a long impulse,
relay 2L will release, while if R stays reversed for a long
impulse, relay lL will release. Thus, these relays select
between short and long impulses.
Either lL or 2L releasing will deenergize LP. By means
of LP the unit which is transmitting adds about lo second
extra time to a long pulse (see Fig. 5) to insure that all
stations which are receiving the pulse have ample time to
release lL or 2L, as the case may be. This allows for
variations in lL and 2L relay timing.
Relay LB is a long impulse bridging relay, and has a repeater LBP. The function of LB and LBP is to remain up
during normal code action, but to drop out and reset the
equipment to normal at the conclusion of a code or in
case of an irregular action. Sirice one relay alone does
not give sufficient time element for bridging normal. operation, considering variations in other relays, the'· cascade
release of relays LB and LBP is required.
Relay SS is a slow acting "station sequence" relay
which insures that field stations transmit indications in
turn. When a field station transmits one indication code,
relay SS picks up to hold out further coding action from
that station until all other stations have a chance to send
an indication code. Relay SS will not drop out until about
37
!
second after lL releases and the line remains qormant.
In this way, stations which have their SS relays down
have preference in starting.
The actual circuits for lL and 2L are somewhat dif..
ferent from those shown in Fig. 9 in order to obtain normally deenergized relays.
·
ST A TION REGISTRY
Control and Indication Codes:
Impulses 2 to 8 inclusive are reserved for station selection. Of these seven impulses, four are always short, and
thnte are long. The· 35 possible station selections are
shown in sequence in Table II.
In the office, the leading pyramid relay (E) picks up on
the first code step to close circuits for selecting_ the F channel relays (See Fig. 10). The first one of the three long
- impulses. selects one F relay over the E relay. .This may
be the 2F, 3F, 4F,5F, or 6F, depending upon. whether the
. first of the three long impulses comes on the 2nd, 3rd, 4th,
5th, or 6th step of the code.
After selecting an F relay, the second of the three long
impulses selects a G or group relay over a front contact of
whichever F was selected. There are five G relays associated with 2F relay, because impulses 3, 4, 5, 6 and 7 are.
all available for group selection. If 3F is selected, impulses
4, 5, 6 and 7 are all available for selecting any one of four
group relays. If 4F is selected, impulses 5, 6 and 7 are
available for selecting any one of three group relays. If
5F is selected, impulses 6 and 7 are available for selecting
one of two group relays. If 6F is selected, impulse 7 is the
only one available for a group relay selection. ·For a 35..
station layout, there are 5 channel and 15 group relays,
I
,l
.
[
-
38
..
5
TRANSMISSION
CHARACTERS
1F
_·- - - - - - - .
{
G
T""
;---_..,___..
ST
0
+
a
(8
..JE_._____r--...,.__ _.
LB~P~------------------------------,
F
iL
G
s
c
CHAIN RELAYS
z TO e
., ,;L__{_:._.------~~~~--------..
~
TYPICAL STATION .SELECTION CIRC_UIT
Ftg. 10
any one of which may be selected by the allocation of the
first two of the three long impulses.
The station or S selection tapers down in the same way
as the O selection. For example, if 230 is selected, im-pulses 4, 5, 6, 7 and 8 are available for selecting any one
of five stations. If 240 is selected, impulses 5, 6, 7 and 8
are available for one of four S selections. If 270 is selected,
- only the 8th impulse is available for station selection.
If 340 is selected, one of four S relays can be selected.
If 670 is selected, 678S is the only S relay which can be
selected. A study of Table II, Part I, will . clarify the
pyramid combinations. There are 35 different S relays,
and any one selected will pick up the SP relay in the
office coding unit.
'
In the office equipment, only the F and O relays which
are directly used in the selection of the S relays r~quired
for a given installation are used.
In the field, station selection is made similar to that
in the office. By means of jumpers 0n the terminal board,
the F, 0, and S relays can be made to pick up on which-39
ever one of the 35--statioh code combinations is required.
Since the :field LCS unit contains only one F and one G
relay, there can be no more S relays (or storage units) than
can be selected over one G relay. This explains why one
LCS unit normally can handle 5 "S" units, two can handle
4 '~ S" units, etc. ·
As mentioned in Part I, when more "S" units are re-quired at a location than can normally be handled by the
F and G relays in the LCS unit, additional F and G relays
can be added to the LCS unit externally in the form of a
:field pyramid unit. Thus, if a pyramid unit containing
4F and 140 relays were added externally to the LCS unit,
that unit could select all 35 "S" relays.
As soon as an F relay is selected, the E relay is released.
When a G relay is selected, the F relay is released. When
an S relay is selected, the G relay is released. This releas-ing of the previous pyramid relay opens selection circuits
to prevent more than one station channel being selecte.d
and provides a definite preference order for station selec-tion when several stations are trying to transmit (See
Fig. 10).
CODE PREFERENCE SEQUENCE
Since it is possible for two or more stations to have
code storages at the same time, each one having an equal
chance to transmit, and since only one station at. a time
R
OFF'ICE
~
R
F'IELD
T
T
Fig. 11
40
can be permitted to transmit a code, a definite order
of station code preference is established.
OFFICE
357
358
356
378
367
368
345
347
348
346
578
567
568
It is also possible for two or more field stations 678
at different locations to start transmission of indi.- 457
cation codes at the same time. It is then necessary 458
to eliminate all but one of the locations so that only 456
one location can complete a code. Inherently, the 478
location holding a shunt on the line circuit can 467
overrule the location that has its shunt removed, 468
provided the former location is nearer the line . 235
battery thf!.p. the latter location (See Fig. 11). Thus, 237
238
-the odd numbered long impulse predominates ov·er
236
the short impulse, and the even.-numbered short 234
impulse predominates over the long impulse.
257
Because of this action, the code preference .se.. 258
quence between field locations has been established 256
278
in the order shown at the right of this page. Thus,
267
the station code assignments given field locations, 268
in their geographic order with respect to the office 245
(at top of the list), will follow the given sequence. 247
When several field locations start indicating at the 248
same time, the one nearest the office having the 246
When two or more stations are. at the same lo.cation, the station code preference (by circuit
design) will follow the sequence in accordance with
the size of the code ~umber. This sequence order
-was given by Table II on a previous page. The sta.tion storage haying the lowest code number will
transmit first, then the next lowest number will be
second, and so on. This is the order in which con.trol codes will be transmitted. A field location that
requires an LCS unit and several storage units will
transmit its codes in this same order.
41
preference code assignment will then eliminate those lo..
cations more remote.
Each field coding unit contains a code disagreement
relay CD. When the field location is transmitting alone
or transmits superior impulses, the line relay R should be
in the normal pos.ition any time its transmitter relay T
is released. When several field locations are transmitting
at the same time, the one that sends an inferior impulse
will have its Hne relay R positioned to the reverse con..
tacts when its T relay is down. This provides a circuit
to pick up the CD relay, which eliminates that station
as a transmitter (See Fig. 12).
M
.
c~----
~B
____ _ _ J
CD
.T,
f'...__--4,-M_.+
tL
B)
I
•
~c
;_A
LBP
t •
(I
Fig. 12
When the office and several field locations start trans ..
mitting at the same time, the control code always takes
precedence. This preference is established on the first
step of a control code, which is made a long impulse.
Relay lL is released in the field unit to close a circuit over
relay 1 front contact to pick up the CD relay and eliminate
the field station as a transmitter (shown in Fig. 12). This
same circuit picks up relay CD at all field stations when
any control code starts to determine that the c,ode is a
control.
It is sometimes found desirable to locate the group of
stations whose first digit is 2 at some location other than
its normal sequence. In order to provide this facility, a
TS relay (secondary transmitter) is controlled over ter ..
42
minat 31 (shown on D2547.-Sh.1). When this is used, the
station calls are limited to those whose first digit is either
2 or 3, making a total of 25 stations on one line circuit.
The use of the TS relay permits stations having 2 as the
first digit to be located in any of the following ways, with
respect to stations having 3 as the first digit.
1. Nearer to the office.
2. Interspersed among other stations.
3. On the -opposite side of the office, thus permitting
one office coding unit to be used with a two wire
line circuit extending in each direction from the
office.
4. A branch line off a main line circuit.
In all these arrangements stations whose codes start
with the same number must retain the sequence within
the group, as shown in the right hand list on page 41.
· The first two arrangements permit flexibility in regard to
the location of stations with a suitable number of storage
units. In the last two arrangements, all stations having
2 as the first digit should be located on one side of the
office or on the main line while those having 3 as the first
digit should be located on the opposite side of the office
or on the branch line.
In the event that two or more stations attempt to indi ..
cate simultaneously, the station which makes its second
pulse short causes the TS relay in the offiee to, rick up
momentarily at the beginning of the third pulse to ,open
the line for a short period. This insures that the R relay
will drop out at the location which is attempting to send
a long second pulse. Thus a station more distant or in a
different direction from the office than the station with
the long second pulse takes its preference and insures that
it will indicate without interference.
',
43
..
r
In order to be sure that under no circumstances will two
or more stations indicate simultaneously, or foreign inter..
ference change station code characters, a code disagree..
ment relay CD is provided in the office coding unit. This
relay picks up during an indication code as soon as 1L,
2L and SP pick up; that is, on the pulse following the one
which selected some station at the office (02547 ..Sh.1).
If there should be a four~h long. pulse in the station selec..
tion portion of the code (2 to 8 inclusive), relay X picks
up over contacts of the CD relay. This positions all line
relays to their reverse contacts and eliminates the stations
transmitting. Normal polarity of the line is then restored,
and all stations are reset to normal before coding is again
resumed.
FUNCTION REGISTRY
Control Code:
After selecting a station, the next problem is to select
the various functions at that station, in order that they
may be controlled to the desired positions. This is done
by assigning a definite step of the code to each controlled
function.
On a control code,_ the 9th impulse is usually used for
normal switch control. In transmitting, if the switch lever
is in the normal position, relay T is stuck up over 1L and
LP so that the line is held open for a long impulse. (02547..
Sh.1). If the switch lever had been in the reverse instead
of the normal position, the 9th impulse would have been
short because T, not having a stick circuit, would have
dropped out for· a short lmpulse. Other lever positions
make the 10th to 15th impulses long or short.
I
In the field unit, since the 9th impulse is long, relay_
1L releases to pick up register relay A. Relay A picks up
44
on each long odd numbered impulse during the last half
of the code, and sticks up during the following· even
numbered impulse. It is then released at the beginning
of the next ~dd numbered impulse (See Fig. 13).
"?.-
.
R
1L
a>>--+-•-
t
A
CR~y-...~c
,f
__
~
ODD NUMBERED
CHAIN RELAY
l
.. .o,...---f
c~.-.+--- - - . : . . . + ~
Fig. 13
In a similar manner, relay 2L releases to pick up reg..
ister relay Bon each long even numbered impulse during
the last half of the code. Relay Bis then stuck up during
. the following odd numbered impulse and is ;eleased at
the beginning of the next even ntimbered impulse.
At the selected station the D relay picks up on the 9th
step of a control code to select a group of function con.trol relays. A maximum of seven function relays can be
controlled by one D relay.
The character of· the odd numbered impulse is reg..
istered by relay A. If it is a short impulse A is down, and
if it is a long impulse A is up. On the following even
numbered impulse, battery is applied by the line relay to a
polar stick relay SR, selected by a counting chain relay
and a D relay. The direction of current flow through the
SR relay is determined by the position of the A relay.
The polar stick relay is then positioned normal when A
is down and reverse when A is up, as shown in Fig. 13.
In a similar manner, relay B registers the character of
the even numbered impulses. Other selected polar stick
45
r-·
relays are positioned in correspondence with the B relay
on the following-odd numbered impulse.
These function control relays are thus progressively
positioned by code impulses. They remain in the operated position without energy until reversed by a current
of opposite polarity.
Indication Code:
In the indication codes, each of a maximum of seven
functions to be indicated is assigned to a particular step
of the code. Assume the steps assigned to functions as
shown on D2547-Shs.1 and 2.
In the field, each function impulse is made short or
long in correspondence with the position of the function·
relay. In the office there are seven register relays, one for
each of the seven function steps. If the impulse is long,
lL or 2L releases to pick up a register relay on the corresponding impulse, which register relay remains up until
the end of the code. (See Fig. 14). This register relay
does not pick up if the impulse is short.
The 9th impulse is long and operates the No. 9_ office
register relay if the switch is normal. The 9th impulse is
short if the switch is not locked normal.
D
s
9
B ~
B)
LBP
B)
I
•
tL
t
CR
• f
•
c
1----y
~
t
c
--.:.._ __, D
f
B)
e...!
K
~ C
!--9--(B
Fig. 14
46
The -10th impulse is long and operates the No. 10
office register relay if the track is occupied. - The 10th
impulse is short if the track is unoccupied.
The 11th ·impulse is long and operates the No. 11
office register relay if the switch is reverse. The 11th im.pulse is short if the switch is not locked reverse.
The 12th impulse is long and operates the No. 12
office register relay if the approach is occupied. The 12th
impulse is short if the approach is unoccupied.
The 13th impulse is long and operates the No. 13
office register relay if the left signal is clear. The 13th im.pulse is short if the left signal is not clear.
The 14th impulse is long and operates the No. 14
office register relay if the power is off. The 14th impulse
is short if the power supply is on.
The 15th impulse is long and operates the No. 15
office register relay if the right signal is clear. The 15th
impulse is short if the right signal is not clear.
In the 'office, the 16th impulse picks up a selected de..
livery relay D and transfers the stored information from
the register relays to the group of indication stick relays
for the individual panel which was selected. (See Fig. 14).
If the function character contained in this code has
changed from what it was in the previous code, the indi..
cation relay picks up or releases accordingly·. - However,
\
.
if the function character is the same as it .was in the pre.ceeding code, the indication relay does not change in
position.
There is a D relay for each panel indicated and a max..
imum of seven indication relays controlled by pne D r~lay.
47
RELAY NOMENCLATURE AND FUNCTIONS
The relays in the code system are of the following types:
1. Field line and starting relays are biased polar relays
(style KP).
·
2. Field function control relays and office line relays
are stick polar relays (style KP).
3. Slow.-release relays are of the square ·armature type
(style L3) neutral relays.
4. All other relays are of the round armature type
(style Ll) neutral relays.
Style KP relays are individually housed and individ. .
ually plug.-connected. Style L relays are housed in groups
in sheet metal cases, the cases being plug-connected as
units (except office storage units).
All relays in the office group and field group of like
nomenclature perform similar functions. Numerical pre. .
fixes indicate the code impulse to which the relay responds.
The nomenclatures and functions of the various relays
are as follows:
R-LINE RELAY-This relay repeats the line impulses at
each location, operating that location's coding equip . .
ment.
T-LINE TRANSMITTER RELAY-This relay transmits to the
line the code impulses generated by the station equip.•
ment.
M-MASTER RELAY-This relay differentiates between
transmission and reception. Each station is normally
a receiver. This relay operates to change the station
into a transmitter.
PC, PCP-LINE PoLE. . CHANGING RELAYs-These relays
operate at the office to reverse the line polarity during
48
an indication code, locking out all field stations which
have not started to transmit.
ST-STARTING RELAY-This relay closes circuits to initiate
code action. At the office it is picked up by operating
a starting pushbutton. In the :field it is released by a
change in any wayside function position. It is reset
on the· eighth step of the code.
lL-LINE "OPEN" SLOW RELEASE TIMING RELAY. At the
transmitting station this relay produces the long
"open" (odd nq.mbered) impulses and at the receiving
station it causes these impulses to be registered.
2L-LINE "CLOSED" SLOW RELEASE TIMING RELAY. At the
transmitting station this relay produces the long
'~closed" (even numbered) impulses and at the receiv.ing station it causes these impulses to be registered.
LP-SLOW RELEASE REPEATER RELAY OF lL AND 2L RELAYS.
On transmission this relay adds timing margins neces.sary to insure registry of the long impulses at the re.ceiving station.
LB, LBP-SLOW RELEASE IMPULSE BRIDGING RELAYS.
These relays in combination bridge the normal open
and closed periods of the line to permit normal code
action and reset code equipment to the norn1al condi..
tion after code action ceases.
.
.
SS-SLOW REL~ASE STATION SEQUENCE RELAY-·This relay
operates" at the transmitting :field station, adding an
extra time delay to that station's initiation of a second
code action. Thus all other stations having first code
storages will receive preference in indicating.
1, 2, 3, 4, 5, 6, 7, 8 and 16-CouNTING CHAIN RELAYSThese relays provide the impulse counting and stepping
49
,...
actio(l. for both sending and receiving operations~ All
but relays 8 and 16 function twice per code at the office
and selected field station. Relay 8- functions in the
middle of the code and relay 16 functions at the end
to terminate the code.
CR-CHAIN REPEAT RELAY-This relay controls the cir-cuits involved in producing the chain repeating action.
It operates in the middle of the code.
E-PYRAMID ENTRY RELAY-This relay prepares the circuits
for station selection channels. It operates on the first
step of any code.
F-PYRAMID RELAY-First station channel selecting relay,
operated by a long impulse on the step numbet by
which it is prefixed.
G-PYRAMID RELAY-Second station group selecting relay,
operated. by long impulses on the step numbers by
which it is prefixed.
S-STATION CALL RELAY-This relay selects the particular
station determined by the code combination trans-mitted. It is operated by long impulses on the step
numbers by which it is prefixed.
SP-STATION CALL REPEATER RELAY-This relay repeats
any one of the possible thirty--five S relays in the office
equipment.
9, 10, 11, 12, 13, 14 and 15-IMPULSE REGISTRYREtAYsThese relays in the office respond to long impulses on
the respective steps, registering the code information
for delivery to final stick relays at the conclusion of
an indication code.
A, B-IMPULSE REGISTRY RELAYs-These relays in the field
respond to long impulses during the last half of a con-50
trol code~ Relay A operate& on line open pulses. Re..
lay B operates on line closed pulses. The function
control .relays are positioned by these registry relays
on the steps following the registering of the impulse
characters.
CD-ConE· D1sAGREEMENT RELAY-This relay in the field
eliminates that station as a transmitter when the office
or another station having a preference code assign..
ment is coding at the same time. In the office this
relay prepares circuits to interrupt an indication code·
having more than three long impulses in. the station
selection portion of the code. These relays. at both
office and field also control the delivery of the regis..
tered impulses.
X-CANCELLATION RELAY-This relay at the office inter..
rupts an indication code if more than 3 long station..
selection impulses are received.
D-DELIVERY RELAY-This relay functions to deliver the
information determined by the registry relays to the.
function control relays and indication stick relays.
This relay operates in the middle of a control code in
the field and the end of an indication code in the office.
MSP-STATION TRANSMITTER REPEATER RELAY-Repeats
M and S relays in the field to connect one ,group of
wayside
. indication circuits to the coding unit for .trans ..
mission of. indications.
NWK, RWK, LHK, RHK, TK, AK, POK, etc. - IN..
DICATION SncK RELAYs-These relays control directly
the indication lamps and train graph pen magnets.
They operate when the assigned impulse is long.
51
,.
.
BR, BZ-BELL RINGING RELAYs-These relay~·operate an
annunciator bell or buzzer, for such indications as
track circuits, etc., that require audible indications.
CO-THERMAL CUTOUT RELAY-In case the field equip..
ment continues to repeat codes because of some irregu..
larity, a thermal relay disconnects that station from
the line periodically to permit other stations to use
the line.
TS-SECONDARY TRANSMITTER RELAY-When branch lines
are used, this relay operates on an indication code to
interrupt momentarily the line energy at the beginning
of the ~hird impulse when the second impulse is short.
This action is required for station elimination.
JBA, JBAP, MP-TELEPHONE SELECTOR SECTIONALIZING
RELAYS-Required when telephone selectors are oper.ated on the code line. These relays prevent code con..
trol operation during selector codes.
52
DETAIL CIRCUITS FOR CODE ACTION
In the back of this manual is a group of drawings,
showing the complete circuits for the code system, as
follows:
D2547-Sh.1-0ffice line--coding unit and typical office
storage unit and panel associated with
one station.
D2547-Sh.2-Field line--coding--storage unit, with asso-ciated wayside relays applying to one
station.
D2547-Sh.3-Complete office pyramid circuits. A
typical field pyramid unit circuit. Sche-matic lirie circuit.
D2547-Sh.4-Code Time Chart, showing time and
sequence of relay operations at the
office and at a field station for one' as-sumed control code and one assumed
indication code.
The circuits for control and indication code action,
as pictured in the CODE TIME CHART, are traced· in
detail in the following pages. In describing a particular
circuit, the purpose is not to list the contacts involved in
the circuit, but rather to explain briefly the action of the
circuit.·
The description will be given in the following order:
1. The office transmitting a control code to station 234
for Normal Switch and Clearing Left Call--on. Signal.
2. Field station 234 receiving the control code for Nor-mal Switch (which is assumed already normal) and
Clearing Left Call--on Signal.
3. Field station 234 transmitting an indication code
for Switch Normal, Left Signal Clear, Approach
track occupancy, and A.C. Power restored.
53
-
4. Office ·receiving indication code from station 234
for Switch Normal (which is assumed already normal), a Left Signal Clear, Approach track occupied,
and Power On.
Following the detailed description is a tabulation, summarizing the sequence of relay operations that are involved
at both the office and field locations, for the selected control and indication codes. This tabulation is in the form
of Table III and appears on Pages 84 to 87.
OFFICE TRANSMITTING CONTROL CODE
Circuit Plan 02547-Sheet 1.
On the panel for the station having code selection 234,
the Switch lever remains in Normal position, Signal lever
is placed to Left Clear position and Call-on Signal button
pulled out. The starting button for the associated panel
is pushed momentarily.
Battery from the starting button picks up relay 234ST.
This ST relay sticks up (over its contact A3) and stores
the code until this panel can send the control code.
(Common for all ST relays is carried over a Knockdown
But!on c;ontact to cancel code action when necessary).
If the code line is at rest and all relays are ·in their
normal positions, 234ST (C3) picks up relay M through
terminal 40. M (A4) picks up relay T to start transmission
of the control code.
1st Step-Line Lock-Always Long.
Back contacts C3 and CS of T open battery to the line .
circuit and all field R relays reverse. Front contact B2
of T operates the office R relay to the reverse position,
controlling the local (lower) coil. Contact 2R of relay
54
R picks up relay lL. lL (A3) picks up relay 2L, which
sticks up over its contact A2.. lL (B2) picks up relay 1,
which sticks up over its contact A2.
_,,.
lL (A4) deenergizes M. 2L (Bl) deenergizes lL, which
starts t1m1ng. lL (B6) and 2L (A6) pick up relay LP.
LP (B2) picks up relays LB and LBP. LBP is held up by
LB (B2). LB (C3) and LBP (B6) stick M picked up.
LBP (B2) and 1 (B6) pick up relay E over terminal 21,
which sticks up over terminal 29.
Relays LB and LBP remain up during the entire code.
LBP (A3 and A-5) connect the counting chain relays to
the line relay R contacts 3N and 4R and LBP (A5) opens
pick up circuit to relay i. LBP (B2 and B4) provide stick
energy for various relays picked up during coding action. ·
LBP (C3) transfers the control of relay lL from line relay
R contact 2R to contact lN.
The first step of a control code is always long, relay T
being stuck up over its A3 contact by battery from relay
1 (B4), over front contacts of relays lL and LP. About
! second after lL is deenergized, it releases and deener.gizes LP, ~hich releases about lo second later. LP then
deenergizes relay T, which releases in about 1/ 20 second
to terminate the 1st impulse.
(The deenergization and reenergization of relay LB by
LP during code action has no bearing on normal -operation
and will not be discussed).
2nd Step-Station Selection-Assumed Long.
Relay Tin releasing closes the line circuit and all field
R relays return to normal. Back contact B2 of relay T
changes polarity of the current through the office R relay
and positions it to normal. R (2R and 4R) deenergize 2L
55
,. .
and 1. R (lN and 3N) pick up lL and 2. Relay 2 sticks
up over its front contact A2. 2 (A5) removes rectifier 7
from relay 1 and 1 releases quickly. LP picks up over the
front contacts of lL and 2L.
Relay 1 (C5) applies battery to the pick up side of
relay T, which would pick up T if this impulse were to be
short. However, this impulse was chosen as long, so ·T
is held down by battery on the opposite side of the coil
of T over its back contact A5 and 2 (B4) from terminal
32 to E (A2).
After about i second 2L releases, deenergizing LP
which releases in about lo second. LP (A5), 2L (B5) and
2 (B6) energize relay 2F over terminal 22. 2F (B3) sticks
2F up and 2F (B5) opens stick circuit of relay E, which
releases to open the F relay selection circuits so that no
other F relay can pick up. 2F (A4) removes hold-down
energy from relay T (through terminal 32), so that T can
pick up to terminate the second impulse.
(It may be seen at this point that the F relay selection,
instead of being on the 2nd impulse, might have been on
the 3rd, 4th, 5th or 6th impulse, depending on the code
setting. The 3F, 4F, 5F, or 6F relay would then have been
selected over terminals 23, 24, 25 or 26, and would have
transmitted the long impulse over terminals 33, 34, 35 or
36 respectively).
3rd Step-Station Selection-Assumed Long.
Relay T opens the line circuit and all field R relays
reverse. Office R is positioned reverse, which deenergizes
lL and 2, and picks up 2L and 3. 2L picks up LP. 3 (A5)
removes rectifier 8 from relay 2 and 2 releases quickly.
(On subsequent steps each chain relay in picking up
removes the rectifier from the previous chain relay to re.56
..
lease it quickly, so no further mention will be made of
this action).
If the impulse were short, the opening of 3 (C4) would
deenergize T. However, since this impulse is assumed
long, relay Tis stuck up over 3 (B4) and terminal 33 to
2F (A4).
Rela,ys IL and LP release in sequence. This selects
relay 230. by applying battery through LP (A5), IL (C5)
and 3 (B6) to terminal 23. 230 (B5) sticks 230 up and
breaks the stick circuit of 2F, which releases to open group
· .selection circuits so no other O relay can be picked up.
230 (A4) deenergizes relay T (through terminal 33), to
release T and terminate the 3rd impulse.
(It may be seen at this point that the O relay selection,
instead of being on the 3rd impulse, might have been on
the 4th, 5th, 6th or 7th impulse, depending on the code
setting. 240, 250, 260 or 270 relays would then have
been selected over 2F from terminals 24, 25, 26 or 27, or
other corresponding O relays over other F relays. The
long impulse would then have been transmitted over ter-minals 34, 35, 36 or 37 respectively).
4th Step-Station Selection-Assumed Long.
The contacts 9f Relay T close the line circuit so all
field line relays R return to normal. The office R. is posi-tioned to normal. Relays 2L and 3 are deenergized.
Relays IL and 4 pick up. IL picks up LP.
Relay 3 releases and contact C4 applies energy to the
pick up side of the T relay. However, since this impulse
is assumed long, the T relay is held down by having energy
applied to the opposite side of the T coil through· 4 (B4)
and terminal 34 to 230 (A4).
57
,.
Relays 2L and.LP release in sequence. This selects the
·234S relay by applying battery through LP (A5), 2L (B5)
and 4 (B6) to terminal 24. 234S (A2) applies that same
energy to terminal 30 to pick up the SP relay in the coding
unit. (The SP relay repeats all 35 S relays). The SP and
234S relays remain stuck up over SP (A3) for the remainder of the code. SP (A3) breaks the stick to 230, which
releases to open the station selection circuits so i;io other·
S relay can pick up. 234S (C3) transfers 234ST stick circuit to terminal 8. 234S (C5) opens the hold-down circuit
for relay T (through terminal 34), and T picks up toterminate the 4th impulse.
(It may be seen at this point that the S selection, instead of being on the 4th impulse, might have been on
the 5th, 6th, 7th or 8th impulse, depending on the code
setting. 235S, 236S, 237S, or 238S relays would then have
been selected over 230 from terminals 25, 26, 27 or 28,
or other corresponding S relays over other O relays. The
long impulse would then have been transmitted over terminals 35, 36, 37 or 38 respectively.)
5th Step-Station Selection-Short.
Relay T opens the line and all :field R relays reverse·
The office R relay reverses to deenergize lL and 4, and
pick up 2L and 5. 2L picks up LP. Relay 4 releases. 5
(C5) deenergizes relay T, which releases to terminate the
5th impulse.
6th Step-Station Selection-Short.
Relay T closes the line and all :field R relays return to
normal. The office R positions to normal to deenergize
2L and 5, reenergize lL and pick up 6. Relay 5 releases
and 5 (C5) picks up relay T, which terminates the 6th
impulse.
58
7th Step-Station Selection-Short.
Relay T opens the line and all field .R relays reverse.
The office R relay reverses to deenergize lL and 6, reener..
gize 2L and pick up 7~ Relay 6 releases. 7 (C5) deener.gi~es relay T, which releases to terminate the 7th impulse.
8th Step-Station Selection-Short.
T closes the line and all field R relays return to normal.
The office R relay positions to normal to deenergize 2L
and 7, reenergize lL and pick up 8. 8 (B2) and SP (C3)
pick up CR, which transfers several circuits so the chain
relays can be used a second time. CR sticks up over its
A5 contact for the rest of the code. 8 (C5) deenergizes
234ST, which releases to cancel the code storage. 7 (C5)
releases and picks up T, which terminates the 8th impulse.
· 9th Step-Normal Switch Control-Long.
Relay T opens the line and all field R relays reverse.
The office R relay reverses to deenergize lL and 8, reener..
gize 2L and pick up relay 1, for the second time, over CR
(C3). Relay 8 releases.
Relay 1 (C5) opens the pick up circuit of relay T, but
T remains stuck up over 1 (B2) to terminal l, which re.ceives battery· from the switch lever normal contaot.
Relays lL and LP release in sequence, releasi:rig T to
terminate the 9th impulse.
10th Step-Special-Short.
Relay T closes the line and all field R relays return to
normal. The office R relay positions to normal to deener..
gize. 2L and 1, and pick up lL and 2. lL picks up LP.
59
,.
Relay 1 releases, and since T has no hold-down energy
over terminal 2, relay T picks up to terminate the 10th
impulse.
11th Step-Switch No~ Reverse-Short.
Relay T opens the line and all field R relays reverse.
The office R relay reverses to deenergize lL and 2, reenergize 2L and pick up 3. Relay 2 releases. 3 (C4) deenergizes
T, and since T has no stick energy over terminal 3, relay
T ·releases to terminate the 11th impulse.
12th Ste·p-Special-Short.
Relay·T closes the line and all field R relays return to
normal. The office R relay positions to normal to deenergize 2L arid 3, reenergize lL and pick up 4. Relay 3 releases, and since T has no hold-down energy over terminal
4, relay T picks up to terminate the 12th impulse.
13th Step-Left Signal Clear Control-Long.
Relay T opens the line and all field R relays reverse.
The office R relay reverses to deenergize lL and 4, reenergize 2L and pick up 5. Relay 4 releases.
Relay 5 (C5) opens the pick up circuit of T, but T remains stuck up over 5 (B2) to terminal 5, which receives
battery from the signal lever left contact.
Relays lL and LP release in sequence, releasing T to
terminate the 13th impulse.
14th Step-Call-on Signal Clear Control-Long.
Relay T closes the line and all field R relays return to
normal. The office R relay positions to normal to deenergize 2L and 5, and pick up lL and 6. lL picks up LP.
Relay 5 releases and 5 (CS) applies pick up energy to T.
60
However, T is held-down by energy over 6 (B2) and ter.minal 6, which receives battery from the call.-on signal
button contact.
Relays 2L and LP release in sequence, allowing T to
pick up to terminate the 14th impulse.
15th Step-Right Signal Control Not Clear-Short.
Relay T opens the line ~nd all :field R relays· reverse.
The office R relay reverses to deenergize lL and 6, and
pick up 2L and 7. 2L picks up LP. Relay 6 releases. 7
(C5) deenergizes T, and since T has no stick ene~gy over
terminal 7, relay T releases to terminate the 15th impulse.
16th Step-Reset-Always Extra Long.
Relay T closes the line and all :field R relays return to
normal. The office R relay positions to normal to deener..
gize 2L and 7, reenergize lL and pick up 16 through CR
(C5). 16 (Bl) deenergizes M. Relay 7 releases, but pick
up energy is kept off the T relay·by 16 (Bl) being open.
Relay M releases.
Relays 2L, LP and LB release in sequence. LB (A3)
releases relay 16. LB (B2) deenergizes LBP, which releases
later. LBP (B2) releases CR, SP, and 234S. LBP (C3) de..
energizes lL. Later lL releases and all the relays have now
been reset to their normal positions.
It may be seen at this point that the office equipment
was ready to receive as soon as LBP released, which was
about t second after the last operation of the office line
relay. However, the office cannot transmit again (pick
up M) until lL releases. This time margin of lL release
is added to the reset period to insure that all coding units
are in receiving condition (LBP relays released) before
any unit can start transmission~
61
FIELD STATION 234 RECEIVING CONTROL CODE
Circuit Plan 0254 7 Sheet 2.
The line relays at all field stations respond to control
codes. The line relay contacts apply local pulses to the
field equipment in accordance with the code received.
The action described below is for station 234 receiving
the control code. Other field stations follow this code
in part, until they determine they are not the station being
called.
Since the action of many of the relays in the field
equipment is so similar to that described for the office
equipment, some of these circuits will not be described
as much in detail.
1st Step-Line Lock-Always Long.
Relay R reverses and picks up lL. lL (A4) opens the
pick up circuit to M so this station cannot start trans ..
mission any time during this code. lL picks up 2L and 1.
2L deenergizes 1L and picks up LP. LP picks up LB and
LBP. LB and LBP remain up during the entire code (al..
though LB may momentarily release while receiving a
code.)
· Since R stays reverse for a long impulse, lL releases.
(lL deenergizes LP. Since LP has no function when re..
ceiving, its releasing on long impulses will not be further
noted). lL (CS) picks up CD over 1 up. (IfM had picked
up simultaneously with the office M, CD (A4)° picking up
would release M to eliminate the field station as· a trans ..
mitter, giving the control code preference). CJ? remains
up for the entire code and prepares control code reception
circuits.
After the proper time element, the office closes the line
circuit to terminate the first impulse.
62
2nd Step-Station Selection-Long.
R returns to normal and deenergizes 2L and 1,_ and
picks up lL and 2. Relay 1 releases.
a
Since R stays normal for long impulse, 2L releases
and, over 2 (B6) and terminal 52, picks up FA, which
sticks over terminal 49.
After the proper time element, the office opens the
line to terminate the second impulse.
3rd Step-Station Selection-Long.
R reverses to deenergize lL and 2~ and pick up 2L and
3. Relay 2 releases.
Since R stays reverse for a long impulse, lL releases
and, over 3 (B6) and terminal 53, picks up GA, which
sticks over terminal 59. GA releases FA.
After the proper time element, the office closes the line
to terminate the third impulse.
4th Step-Station Selection-Long.
R goes normal to deenergize 2L and 3, and pick up lL
and 4. Relay 3 releases.
Since R stays normal for a long impulse, 2L releases
and, over 4 (B6), GA (B4) and terminal 64, picks up S,
which sticks up over terminal 39. S releases GA.
After the proper time element, the office closes. the line
to terminate the fourth impulse.
'
. It should be noted at this point that if the station code
setting had been other than 234, FA would have been
picked up over another terminal (53, 54, 55 or 56), GA
would have been picked up over another terminal (54,
55, 56, or 57), and S would have been picked up over another terminal (65, 66, 67 or 68).
63
In cases where a Field Pyramid Unit is used (D2547..
Sh.3), depending on connections, E would have been
picked up by terminal 51 as soon as 1 and LBP pick up.
FB would have been picked up either by FA through ter..
minal 63, or directly over a terminal (53, 54, 55 or 56). GB
would have been picked up over a terminal (54, 55, 56 or
57). The S relay would then have been picked up over
a terminal (55, 56, 57 or 58), under control of GB and
through terminals 1, 2, 3 and 4 of the Pyramid Unit. When
only one station channel F selection is required, FB is a
repeater of FA, used to select GB. When a second station
channel F selection is required, FB is used·as the second F
relay, and E relay is used to select between FA and FB.
Other field pyramid unit combinations can be designed
to operate in a similar manner.
5th Step-Station Selection-Short.
R reverses to deenergize lL and 4, and pick up 2L and
5. Rel~y 4 releases.
6th Step-Station Selection-Short.
R goes normal to deenergize 2L and 5, reenergize 1L and
pick up 6. Relay '5 releases.
7th Step-Station Selection-Short.
R reverses to deenergize lL and 6, reenergi~e 2L and
pick up 7. Relay 6 releases.
8th Step-Station Selection-Short.
R goes normal to deenergize 2L and 7, reenergize 1L
and pick up 8. CR picks up over 8 (B2), terminal 37 and
S (C7). CR transfers several circuits so the chain relays
can be operated a second time. Relay 7 releases.
64
(It ~hould be noted at this point that at other :field
stations than at station .234, their FA, GA or S relays
were not selected. On the 8th step, the S not being up,
their CR relay would not pick up, so further counting
chain action at those stations is discontinued. However,
the R, lL, 2L, LP, LB and LBP relays continue to operate
to the end of the code, and CD remains up).
9th Step-Normal Switch Control-Long.
R reverses to deenergize lL and 8, reenergize 2L and,
over CR (C6), pick up relay 1 for the second time. ~elay
. 8 releases, which picks up the selected D relay over ter.minal 16 and the selected S relay. The D relay closes
control circuits to the group of function control relays
(WSR, LHSR, RHSR, USR, etc.), which are of the polar
stick type. D (C4) opens the stick circuit for ST and ST
reverses.
Since R stays reversed fot a long impulse, lL releases
and picks up relay A.
After the proper time element, the office closes the line
to terminate the ninth impulse.
10th Step-Special-Short.
R goes normal to deenergize 2L and 1, and pick up 1L
and 2. R also sticks A up and applies battery· over A
(A3), 1 (B4) and terminal 9 to position WSR normal (or
check the normal position if already normal). Relay 1
releases and removes battery from terminal 9.
11th Step-Switch Not Reverse-Short.
R reverses to deenergize lL and 2, reenergize 2L, re ..
lease.!).., and pick up 3. Relay 2 releases .
.65
,..
.
With A down when 3 picks up, common is applied to
terminal 11. Both sides of relay WSR m;e connected to
common, so WSR relay position is not disturbed. (If the
control had been. for reverse Switch, WSR would have
had common on both sides on the 9th step, and would
have been positioned to reverse on the 12th step by bat..
tery from terminal 11).
12th Step-Special-Short.
R goes normal to deenergize 2L and 3, reenergize lL and
i::,ick up 4. Relay 3 releases.
13th Step-Left Signal Clear Control-·Long.
R reverses to deenergize 1L and 4, reenergize 2L and
pick up 5. Relay 4 releases.
Since R stays reverse for a long impulse, lL releases
and picks up relay A.
After the proper_ time element, the office closes the
line to terminate the 13th impulse.
14th Step-Call-on Signal Cl~ar Control-Long.
R goes normal to deenergize 2L and 5, and pick up 1L
and 6. R also sticks A up and applies battery over A
(A3), 5 (C3) and terminal 13 to LHSR, which receives
common from terminal 81 and A (C3). This reverses
LHSR to the clear signal position. Relay 5 releases and
removes battery from terminal 13. (If LHSR is to be
positioned to normal for stop signals, A would- be down,
battery applied to terminal 81, common applied to ter.minal 13, and the current through LHSR would flow in the
opposite direction, positioning LHSR to normal.
Since R stays normal for a long impulse, 2L releases
and picks up relay B.
66
;·
·1.
I
I
After the proper time element, the office opens the ·
line to terminate the 14th impulse.
15th Step-Right Signal Not Clear-Short.
R reverses to deenergize lL and 6, and pick up 2L and
7. R also sticks B up and applies battery over B (A3),
6 (C3) and terminal 14 to USR, which receives common
through terminal 82 and B (C3). This reverses USR to the
clear call-on signal position. Relay 6 releases and removes
battery from terminal 14. (If the call-on signal were to
be red, B would be down and current_through USR would
flow in the opposite direction, positioning USR to normal).
It should be noted at this time that if controls had
been handled over the special steps 10 and 12, the operation would be similar to that just described for the 14th
step. The controlled relays would be positioned by relay
B on the 11th and 13th steps, with battery or comtno~
on terminals 10 and 12, and the opposite polarity ob:.
tained from terminal 82.
·
16th Step-Reset-Always Extra Lorig.
R returns to normal to deenergize 2L and 7, reenergize
lL, release B, and pick up i6 over CR (AS). With A
down, R also applies battery over A (C3) and terminal
81 to RHSR, which receives common through terminal 15
7 (C3) and A (A3). This positions RHSR p.ormal (o;
checks the normal or "red" position if already normal).
Relay 7 releases and removes common from terminal 15°
.
Relays 2L, LP and LB release in sequence. (When 2L
releases, it picks up B, but B serves no function on the
16th step). LB (A3) releases relay 16 and LB (B2) deenergizes LBP. A little later LBP releases. LBP (A3) re..
leases CR, S, CD and B. LBP (C3) deenergizes lL. CD
67
(A3) releases D. Finally relay lL release~, and all relays
have now been reset to their normal' positions.
It may be seen at this point that when LBP released,
which was about f second after the last operation of the
line relay, the field station was ready to receive another
code. However, the field station cannot start transmission
of an indication code (pick up M) until lL releases. This
added time insures that all stations reset before any one
can st~rt another code.
WAYSIDE CIRCUITS
Since wayside circuits will vary in design on the dif,
ferent installations, no attempt will be niade in this manual
to describe them. However, the functions of the wayside
relays associated with the code system will be mentioned.
The CONTROL RELAYS are "KP" type polar stick
relays, operated from the code equipment by an impulse
of energy of one polarity or the other, and remaining in
the last operated position without energy.
· WSR controls a switch to normal or reverse.
LHSR controls signals for left,hand traffic to clear or
to stop.
RHSR controls signals for right,hand traffic to clear or
to stop.
USR controls call,on signals to clear or to stop, the
left or right direction being determined by
LHSR or RHSR.
LHSR and RHSR can be controlled to place signals
at stop either by code or by track occupancy.
Provision has been made for special controls similarly
operated.
The INDICATION RELAYS are standard signal re,
lays. Those having contacts in the starting relay circuit
should possess an open circuit time of not less than 0.01
68
second when the contacts cross over from front to back
or from back to front.
I
NWPR repeats the switch when normal and locked.
RWPR repeats the switch when reverse and locked.
LGPR repeats all left--hand traffic signals at stop.
RGPR repeats all right--hand traffic signals at stop.
ASPR operates when signals are at stop and time re-lease is operating.
TR; TPRA, TPRB, etc., repeat the OS track section.
AR repeats the approach track section.
POR repeats the AC power condition.
Other indication relays are similarly used.
~
FIELD ST A TION STARTING CIRCUITS
It was mentioned previously that while the field station
was _receiving the control code, the D relay picking up
opened the stick battery to the starting relay ST, reversing
ST to store an indication code. It should be noted that
ST obtains common through the front or back contacts
of all function indicating relays in series. Any function
changing position, not as a result of a control code, will
momentarily deenergize ST, which reverses to store an
indication.
Sometimes due to a busy line, the indication may be
delayed. A short fast train may occupy a short OS section
for so little time that it may become clear before the occu-pied code has been sent in. When it is desirabl~,to insure
that the occupied code will b~ transmitted, (as fbr instance
when the OS is recorded on a train graph), the track re-peater relays can be made stick relays. These relays
(shown as TPRA and TPRB) ·would release with the main
track relay, storing the indication code, but would not
pick up again when the main track relay picked up unless
the occupied code has been ~ent and ST is up.
.
69
r
FIELD STATION TRANSMITTING INDICATION CODE
Circuit Plan 02547 Sheet 2.
It has been assumed that station 234 received a control
code to clear a left call-on signal with normal switch. · The
ST relay was reversed by the control code to store an
indication code. As the indication code is starting, it is
assumed that the left call-on signal clears and LGPR releases; that the approach becomes occupied and AR
releases; that the power had been off and now comes on
again so POR picks up; -and that the switch already was
normal so NWPR remains up and R WPR remains down,
and LR is released by the clearing of the signal to lock the
switch controls.
When a field station has a code storage (ST reversed)
and the line circuit is clear so that all relays are in their
normal positions, including 1L, 2L and SS down, relay M .
is picked up by ST (ZR) over terminal 48. M sticks up
over its A3 contact until the end of the code or until eliminated by CD operating.When_ M picks up, it pole-changes the connections to
its line relay R by contacts AS and CS. Its contact CS
also shunts the line relay and its resistor, reducing the
relay current to zero, and R is positioned to reverse. This
shunt causes an increase in the line-circuit current, which
passes through the primary windings of the impulse transfarmer. As a result of the change in line current, an impulse is produced in the transformer secondary of such
polarity as to operate the office line relay R to tl\e reverse
position. ·This shunt also reverses all field R relays more
distant from the office.
1st Step-Line Lock-Always Short.
. In the field, the R relay reverses and energizes lL ov~r
terminal 93. When the M relay picked up, it also picked
70
up relay T over M (B2). M (D4) energizes the thermal·
relay CO.
In the office, the R relay reverses and picks up the pole..
changer relay PC, which reverses the line polarity. The
R relays at all other locations not transmitting are re,
versed and they remain reversed throughout this code .
to lock,out those stations from following the code and to
prevent their starting transmission during "the coding
action.
lL picks up at the transmitting station. lL picks up
2L and 1. 2L deenergizes lL, which starts timing. 2L
picks up LP. LP picks up LB and LBP. LBP (C5) opens
the original line shunt path, but the shunt is maintained
by T (C3). LBP (C3) transfers the lL relay contr9l from
the 2R to the lN contact of R through terminal 94. LBP
(B2 and B4) cqnnect the counting chain relays to terminals
95 and 96~ and open the pick up circuit to relay 1. LBP
(A3) provides stic-k battery for certain relays which will
be picked up later in the code. LBP (A3) or LB (C4) re..
moves battery from the pickup circuit of relay T, and
since T has no stick battery, because this step is to be short,
T releases to terminate the first impulse.
(If the office had started transmission simultaneously
with this field station, the release of T would not position
R to normal, because the line would be deenergized. lL
would then release, picking up CD over lL (C5) and 1
(C3). CD would release M and eliminate this station as
a transmitter).
2nd Step-Station Selection-Assumed Long.
For simplicity of circuits the station code combination
is made the same for both control and indication codes.
71
r-
When T releases, T (C3) removes the shunt from the
line and its R relay, permitting line current to flow through
R .. Since M reversed the R relay connections, and the
office PC reversed the line polarity, the R at the transmitting field station receives the proper polarity. The
removal of the line shunt also places the line relay resistance_ across the line, which reduces the line current.
This current change produces an impulse current in the
' impulse transformer secondary of such polarity that the
office R relay positions to normal.
When R goes normal, it deenergizes 2L and 1, reenergizes lL, and picks up 2. Relay 1 releases.
(Since many circuits operate the same as previously
described, they will not be described in as much detail
from now on).
When 1 releases it applies pick up energy to -T, but T
is held down by battery over 2 (B4), terminal 72 to code
setting and terminal 46 and ST (4R). 2L and LP release
and, over terminal 52 and code-setting, pick up FA. FA
(C3) removes hold-down battery from T and T picks up,
terminating the 2nd impulse.
3rd Step-Station Selection-Assumed Long.
T shunts the line and reverses the office and field R
relays. R reverse deenergizes lL and 2, and picks up 2L
and 3. 2L picks up LP.
When 3 picks up, it removes pickup battery' from T,
but T sticks up over 3 (B4), terminal 73 to code setting
and FA (C3) up. lL and LP release and, over terminal
53 and code setting, pick up GA, which r~leases FA. GA
(A2) removes stick battery from T, which releases to terminate the 3rd impulse.
72
4th Step-Station. Selection-·Assumed Long.
T removes the line shunt and office and field R relays
go normal. R deenergizes 2L and 3, and picks up lL and
4. lL picks up LP. Relay 3 releases.
When 3 releases, it applies pick up battery to T, but T
is held down over 4 (B4), GA (A2), terminal 84 to code. .
setting. 2L and LP release and, over terminal 64 and code
setting, pick up the selected S relay, which releases GA.
S picks up the selected MSP o·ver terminal 8. MSP con. .
nects a group of function indication circuits (terminals 1,
2, 3, 4, 5, 6 and 7). to the T relay control circuits. MSP
(C5) picks up relay SS (the extra timer relay for subse. .
quent code starting), which sticks up over terminal 28
as long as lL (B2) or 2L (C5) remain up due to continuous
coding on the line. S (A5) removes hold,down battery
from T, which picks up to terminate the 4th impulse.
(For other code settings FA, GA and S would have
been selected over terminals 53, 54, 55, 56, 57, 65, 66, 67
or 68. The T control circuits would have been provided
over terminals 73, 74, 75, 76, 77, 85, 86, 87 or 88.
If a field pyramid unit had been used, D254 7,Sh. 3,
the E, FB and GB relays wc/uld have been selected, as pre. .
viously explained. The T relay control battery would
then be through terminals 11, 12, 13 or 14 of the field
pyramid unit and the code setting co:nnections as shown
on D2547-Sheet 3.
-·
If several field stations had been transmitting at the
same time and this station being described were sending
an inferior impulse, the R relay would be reverse when T
relay was down. In that case, battery from R (4R), 95,
16 (C5), LBP (B4), CR (C6), T (C5), M (B6) and 1 (C3)
would pick up CD to drop out M and release this station
as a transmitter).
73
,-
.
. -·-
5th Step-Station Seledion-Short.
T shunts the line to reverse the R relays. R deener.gizes lL and 4, and picks up 2L and 5.. 2L picks up LP.
Relay 4 releases.
Relay 5 releases T to terminate the 5th impulse.
6th Step-Station Selection-Short.
T removes the line shu_nt and the R relays go normal.
R deenergizes 2L and 5, reenergizes lL and picks up 6.
Relay 5 releases and picks up T to terminate the 6th
impulse.
7th Step-Station Selection-Short.
'
T shunts the line and reverses the R relays. R deener..
gizes lL and 6, reenergizes 2L and picks up 7. Relay 6
releases.
Relay 7 releases T to terminate the 7th impulse.
8th Step-Station Selection-Short.
T removes the line shunt and the R relays go normal.
R deenergizes 2L and 7, reenergizes lL and picks up 8.
8 and S pick up CR, which sticks up for the rest of the
code. Over CR (C3), 8 (C3), MSP (A6) and terminal
44, ST is positioned to normal, and sticks up over terminal
42, MSP (A2) and. LB (AS). CR (C3) also deenergizes
the thermal relay CO.
Relay 7 releases and picks up T to terminate the 8th
impulse.
9th Step-Switch Normal-Long.
T shunts the line to reverse the R relays. R deener..
gizes lL and 8, reenergizes 2L and picks up 1 for the second
time over CR (C6).
74
...
Relay 1 removes pick up battery from T, but Tis stuck
up by battery from terminal 1 and NWPR up. lL and LP
release to deenergize T. T releases to terminate the 9th
impulse.
(If the switch were not normal this impulse would be
short, with no battery on terminal 1).
10th Step-OS Track Clear-Short.
T removes the line shunt and the R relays go normal.
R deenergizes 2L and 1, and picks up lL and 2. lL picks
up LP.
Rel_ay 1 releases and picks up T to terminate the 10th
impulse.
(If the OS were occupied, T would be held down for
a long impulse by battery oh terminal 2).
11th Step-Switch Not Reverse-Short.
T shunts the line and the R relays reverse. R deenergizes lL and 2, reenergizes 2L and picks up 3. Relay 2
releases.
Relay 3. releases T to terminate the 11th impulse.
(If the switch were reverse instead of normal, the 9th
impulse would have been short and the 11th made long
by holding T up with battery on terminal 3. If the,switch
were open, both 9 and 11 impulses would be short, with
no battery on terminals 1 and 3).
· 12th St~p-Approach Occupied-Long.
T removes the line shunt and the R relays go normal.
R deenergizes 2L and 3, reenergizes lL and picks up 4.
75
r .-
Relay 3 releases and applies pickup battery to T, but
T is held down by battery from terminal 4 and AR1 down.
2L and LP release, opening the hold down circuit, so T
picks up to terminate the 12th impulse.
(If the approach had been clear, this impulse would
have been short, with no battery on terminal 4).
13th Step-Left Signal Clear-Long.
T shunts the line and the R relays reverse. R deenergizes 1L and 4, and picks up 2L and 5. 2L picks up LP.
Relay 4 releases.
Relay 5 removes pick up battery from T, but T is stuck
up by battery from terminal 5 and LGPR down. 1L and
LP release to deenergize T. T releases to terminate the
13th impulse.
(If the left signals were all at stop, the 13th impulse
would have been short; with no battery on terminal 5).
14th Step-Power On-Short.
T removes the line shunt and the R relays go normal.
R deenergizes 2L and 5, and picks up 1L and 6. 1L picks
up LP.
Relay 5 releases and picks up T to terminate the 14th
impulse.
(If the power were off, T would be held down for a long
impulse by battery on terminal 6).
15th Step-Right Signal Not Clear-Short.
T shunts the line and the R relays reverse. R deenergizes 1L and 6, reenergizes 2L and picks up 7. Relay 6
releases.
Relay 7 releases T to terminate the 15th impulse.
76
...
(If the right signal had been clear instead of the left,
13 would have been short and 15 held long by battery on
termin3:l 7. If all signals were at stop, both 13 and 15 impulses would be short. If the· time release were operating,
both 13 and 15 impulses would be long, with ASPR relay
up).
It should be noted that during the last half of an indication code the A and B relays would be picking up and
releasing, similarly as explained for the control code.
However, since they serve no function in an indication
code, no mention has been made of their operation.
16th Step-Reset-Always Extra Long.
T removes the shunt and the R relays go normal. R
deenergizes. 2L and 7, reenergizes lL and picks up 16.
16 (Bl) releases M, which restores the normal polarity
connections to the R relay. R may go reverse for a
moment,· but 16 (AS and CS) connect terminals 93 to 94
and 95 to 96, which prevents any affect on the apparatus.
In the office, the R picks up 16, which releases PC to
restore normal polarity to the line circuit. All field line
relays, including the one completing transmission, go
normal and they start resetting the equipment.
Relay 7 releases. ~ (D6) releases MSP. MSP (A2)
establishes a direct stick circuit for relay ST. 2L, LP and
LB release in sequence. LB (A3) releases 16. LB (~2) deenergizes LBP. LBP (A3) releases CR, S and B and the
unit is ready to receive. LBP (C3) deenergizes lL.. lL
releases and this location is ready to transmit a code
starting from another storage unit, should it be its first
code. lL (B2) deenergizes SS. Later when SS releases.
this same storage un1t can transmit a second code. Since
other stations having first codes and all control codes can
77
,..
start in immediately after lL releases, lL (B2) and 2L (C5)
will keep SS picked up as long as coding continues, pre..
venting this station starting its second code storage until
the line is clear sufficiently long to release relay SS.
OFFICE RECEIVING INDICATION CODE
Circuit Plan 02547 Sheet 1.
1st Step-Line Lock-Always Short.
When the field station shunts the line, the increase in
line current causes an impulse to be delivered from the
secondary of the impulse transformer to the· office R relay
of such polarity as to position R to reverse by current
flowing through its upper (line) coil from terminals 43, 44,
45, 46, 47 and 48.
R (4R) picks up PC, unless M comes up simultaneously.
PC (B2 and B5) pole--changes the line circuit. PC (C3)
picks up PCP. The pole--changing of the line current pro.duces undesired impulses in the transformer secondary.
To prevent these impulses affecting the R relay, PC (C5)
shunts the secondary winding until PCP (C5) picks up
to break the shunt, and PC (A5) applies battery to the R
relay lower (local) coil of such polarity as to hold R re-verse until PCP (B2) and 2L (C5) pick up to open this
holding circuit.
R (2R) also picks up lL. lL picks up 2L and 1, and
opens M pickup circuit. 2L picks up LP and deenergizes
lL. LP picks up LB and LBP. Ll?P establishes circuits
previously described. LBP also picks up E over terminal
21, and sticks up PC until the end of the code.
2nd Step-Station Selection-Long.
The field station removing the line shunt produces an
impulse in the transformer secondary of opposite polarity,
78
...
which positions R to normal. R deenergizes 2L and 1,
reenergizes lL and picks up 2. Relay 1 releases.
2L releases and .picks up 2F, which releases E. (During
this code lL or 2L releasing will deenergize LP, but since
LP serves no function on indication codes, no further
mention of this action will be made.)
3rd Step-Station Selection-Long.
R reverses and deenergizes lL and 2, and picks up 2L
and 3. Relay 2 releases. lL releases and picks up 23G,
which releases 2F.
4th Step-Station Selection-Long.
R goes normal and deenergizes 2L and 3,. and picks up
lL and 4. Relay 3 relea~es. 2L releases and picks up 234S
and SP in sequente. SP releases 23G and sticks 234S and
itself until the end of the code.
(For other station code combinations, other F, G and
S relays would be selected, as described before).
5th Step-Station Selection-Short.
R reverses and deenergizes lL and 4, and picks up 2L
and 5. Relay 4 releases. With lL (B6), 2L (A6), PC (A3)
and SP (CS) all closed, relay CD picks up and sticks up
until the end of the code. Should, for some reason, a
fourth long impulse be received among impulses' 2 to 8,
relay X would pick up over CD (A3 or C3). X would
cancel the code action and force a reset so the indicating
stations would have to start over again.
6th Step-Station Selection-Short.
R goes normal and deenergizes 2L and 5, reenergizes lL
and picks up 6. Relay 5 releases.
79
7th Step-Station Selection-Short.
R reverses and deenergizes lL and 6, reenergizes 2L
and picks up 7. Relay 6 releases.
8th Step-Station Selection-Short.
R goes normal and deenergizes 2L and 7, reenergizes
lL and picks up 8. 8 and SP pick up CR. Relay 7 releases.
9th Step-Sw.itch Normal-Long.
R reverses and deenergizes lL and 8, reenergizes 2L
and over CR (C3) picks up 1 for the second time. Relay
8 releases.
lL releases and, over CR (B5) up and 1 (C3), picks up
register relay 9, which sticks up until the end of the code.
10th Step-"OS 11 Track Clear-Short.
R goes normal and deenergizes 2L and 1, and picks up
lL and 2. Relay 1 releases. This impulse being short,
register relay 10 does not pick up.
11th Step-Switch Not Reverse-Short.
R reverses and deenergizes 1L and 2, reenergizes 2L
and picks up 3. Relay 2 releases. This impulse being
short, register relay 11 does not pick up.
12th Step-Approach Occupied-Long.
R goes normal and deenergizes 2L and 3, .reenergizes
lL and picks up 4. Relay~ releases.
11
2L releases and, over CR (B2) up and 4 (C3), picks....up
register relay 12, which sticks up until the end of the code.
13th Step-Left Signal Clear-Long . .·
R reverses and deenergizes lL and 4, and picks up 2L
and 5. Relay 4 releases.
80
lL releases and, over CR (BS) up and 5 (C3), picks up
register relay 13, which sticks up until the end of the code.
14th Step-Power On-Short.
R goes normal and deenergizes 2L and 5, and picks up
lL and 6. Relay 5 releases. This impulse being short,
register relay 14 does not pick up.
15th Step-Right Signal Not Clear-Short.
R reverses and deenergizes lL and 6, reenergizes 2L
and picks up 7. Relay 6 releases. This impulse being
short, register relay 15 does not pick up.
/
16th Step-Registry and Reset-Always Extra Long.
R goes normal and deenergizes 2L and 7, reenergizes
lL and picks up 16. Relay 7 releases.
16 (B3) releases PC and 16 (CS) opens the R relay line
coil circuit. PC releases PCP. PC restores normal line
polarity, picking up all field R relays to start those stations
resetting their equipment to the normal conditions. The
pole,changing line current produces an impulse in the
transformer secondary. To prevent this impulse affecting
the R relay, PC (CS) shunts the transformer secondary
winding until PCP (CS) breaks the shunt, and PC (AS)
applies common to the R relay lower coil which holds R
normal until PCP (BS) opens this holding circuit.
16 (C3) also picks up the 2340 relay, selected by. 234S
from terminal 16. Relay D opens the stick circuits of a
group of indication relays and connects these relays to
terminals 9, 10, 11, 12, 13, 14 and 15, which receive battery
from the corresponding register relays that are picked up.
In the assumed case, NWK was already up, and while D
is up NWK is held up by 9 (C3). TK was down and re,
81
r- .
mains down because 10 (C3) is open. R WK was down
and remains down because 11 (C3) is open. AK is picked
up by 12 (C3). LHK is picked up by 13 (C3). POK was
up' but is released because 14 (C3) is open. RHK was
down and remains down b~cause 15 (C3) is open. While
AK is picking up, a special bell-ringing contact applies an
impulse of energy to pick up relay BR momentarily, which
operates a single stroke bell to provide an audible annunciation of track occupancy. This special contact does
not operate BR when the relay is releasing.
Relays 2L, LP and LB release in sequence. LB (A3)
releases 16. 16 (C3) releases 234D. D disconnects the
indication relays from the registry relay busses and estab- lishes the stick circuits to hold up those indication relays
which had been picked up or held up. LB (B2) releases
LBP. LBP (B2 and B4) releases 234S, SP, CR, CD and
all registry relays. LBP (C3) deenergizes lL. The office
equipment is now in position to receive another indication.
lL releases, and the office equipment has been reset to
normal condition and can start transmission.
The indication relays that are picked up light indication lamps on the lever operating panel and track model
to provide visual indications of the positions of the functions. NWK keeps the normal switch lamp lighted. LHK
lights the left signal lamp and extinguishes the red signal
lamp. AK lights the approach track section lamp. POK
extinguishes the power off lamp. (When the switch is
open, both normal and reverse switch lamps . are dark.
When the signals are at stop, the red signal lamp is lighted.
When the time release is operating, all signal lamps are
dark).
When a CBraphic Recorder is used, the corresponding
pen magnet on the train graph is operated as long as a
track indication relay remains picked up.
82
The foregoing description discussed detail code action
for one assumed code combination. The various other
code combinations operate the code equipment in a similar
manner.
The foregoing description of a certain assumed control
code and an indication code, transmitted by one location
and received by another location, can be briefly summar..
ized by the following Table III. This tabulation shows
the sequence of relay operations, without regard to any
relationship to their time of operation. These same relay
operations, plotted with respect to their relative time of
operation, are shown by the Code Time Chart, D2547..
Sh. 4.
The symbols used in Table III have the following mean,ings:
t
Neutral relay pickup ...............
Neutral relay release ............... t
Polar· relay operated to normal. ..... +
Polar relay operated to reverse ...... +
83
TABLE Ill
SEQUENCE OF CODE RELAY OPERATIONS
CONTROL CODE
STEP
I
It(
STARTING BUTTON OPERATED
234~Tt
Mt
Tt
<.,
<(z
1-UI
u
w
-z
..J
1
(LONG)
'
2
(LONG)
~
'Q"
z
-
3
(LONG)
~
(/)
....__
z
0
I-
u
4
(LONG)
w
..J
w
(/)
5
z
(SHORT)
~
6
0
I(/)
1
t
LBP +
(SHORT)
7
(SHORT)
8
(SHORT)
(AT STATION 234)
1
+
LBP +
IL+
co+
LP+
LP+
T+
R+
1 L + 2+
LP+ 1 +
2L +
R+
1L+ 2+
LP+ I +
2L +
f" A +
LP+
Lp +
2 f" t
T+
E+
R+
2L + 3 +
LP+ 2 +
1 L +
GA+
f" A +
LP+
R+
!")
(\J
0
I-
1L t
2L t
LP+
LB+
E +
1L+
FIELD RELAYS
R+
1L +
2 Lt
LP t
LB+
R+
'.:!::'.'.
u
w
I
OFFICE RELAYS
2L + 3 +
Lp + 2 +
1L +
LP+
23Gt
2 f" +
T+
R+
1 L t 4 +
LP+ 3 +
2L +
LP+
234S +
s pt
T+ 23G+
R+
2.L t 5 +
LP t 4 +
T+
R+
6 +
5 +
Tt
R+
7 t
6 +
T +
R+
8 +
7 + CR t 234ST+
T+
84
R +·
1 L t 4+
Lp + 3 +
2L +
s +
GA+
Lp +
R+
2L t
LP t
5 t
4 +.
R+
6 +
5 +
R+
7 +
6 +
R+
8 +
7 + CR t
TABLE Ill (Continued)
SEQUENCE OF CODE RELAY OPERATIONS
CONTROL CODE
STEP
-z
R-+
1 +
8 +
0
9
...,
(LONG)
...,I
u<
LJ <
...,
z
a2
z
<
,
II)
0::
<
uJ: ...,
LJ
....
iu
II)
...,
f
I
t
I
<
:::?
0::
-0
z
Cl)
..J
1L +
R+
I L + 2 +
(sHORT) LP+ I +
Tt
R+
1 L + 2 + 1 WSR +
Lp + 1 +
R+
3 +
(sHORT) 2 +
T+
R+
3 t A+
2 +
R+
4+
(sHORT) 3 +
T t
R+
4 t
3 +
10
11
12
13
(LONG)
R+
5 +
4 +
1L +
0::
I-
z
14
z
(LONG)
u
R+
2L + 7 +
(sHORT) LP t 6 •
T+
z
:)
u..
Cl)
w
0::
R+
1 L t 6 + 2LHSR+
LP t 5 +
2L +
8 +
Lp +
LP+
T+
R+
2 L + 7 + A+
LP t 6 +
15
16
(LONGJ
LP+
LB+
16 +
LBP +
2 3 4 S + SP+
2U SR+
'
R+
16 t
7 +
M+
2L +
I-
w
4 +
1L +
A+
LP+
R+
1Lt 6 t
LP t 5 +
2L +
0
0
I-
R+
5 t
LP+
T +
0
u
FIELD RELAYS
R+
1 +
8 +
D +
ST+
IL+
A+
Lp +
LP+
T+
...,
~
OFFICE RELAYS
CONTINUED
R+
1 6 t
7 +
CR+
1L+
85
B
2L +
B +
LP+
LB+
16 +
LBP+
s+ B+
D+
1L +
*
2R"HSR+
CR+
CD+
,.. .
TABLE Ill (Continued)
SEQUENCE OF CODE RELAY OPERATIONS
INDICATION CODE
~
WAY.SIDE RELAY OPERATES
ST-+ (AT STATION 234)
CO ON
Mt
C)
~ ?;
1/)
R-+
1 .Lt
Wu
2 Lt
1
Zw
LP t
- :::c
...Ju (SHORT) LB t
::s::
2
(LONG)
,,,,----..
~
(1)
C\J
z
~
I0
3
(LONG)
..!!2-,
u
w
_J
w
Cf)
z
0
~
ICf)
R+
1 Lt
2Lt
LPt
LB+
E t
Tt
1t
LBPt
T+
R+
2 t
1 +
2L +
-
Lp +
FAt
T t
Lp +
GAt
FA+
T+
R+
2 t
1 +
2L+
2Ft
E +
Lp +
MSP t
ss+
R-+
2L + 5 +
LP t 4+ co+
5 +
4+
R+
6 +
5 +
R+
7 +
6 +
(SHORT) T+
R+
7 t
6 +
R+
R+
7
8 +
7 +
(SHORT) Tt
L BP t
R+
1 Lt 4 t
LP t 3 +
2L +
2345+
s pt
23G+
Lp +
(LONG}
8
PCt
PCP+
.
4
Lp +
s +
GA+
Tt
R,..
2 Lt
5
LP+
(SHORT} T+
R+
6 t
6
5 +
(SHORT) T+
1t
R+
2Lt 3 +
LP+ 2 ..
1 L +
23Gt
2 F +
LP+
R+
2L t 3 t
LP t 2 +
1L +
R+
1 Lt 4 t
LP t 3 +
2L +
z
-0
I-
OFFICE RELAYS
FIELD RELAYS
STEP
I
CR+ CO
ST+-
8
OFF
86
+
7 +
CR t
TABLE Ill (Continued)
SEQUENCE OF CODE RELAY OPERATIONS
INDICATION
FIELD RELAYS
STEP
.....-:::-0::
<(
w
9
.J
u
.J O
<(
(LONG)
w
za.
.
R+
1 +
8 +
1 L +
At
Lp +
T+
CODE
CONTINUED
OFFICE RELAYS
R+
1 +
8 +
1L +
9 +
LP+
C)
- ::::>
R+
(/)
u
1 L + 2+
10
I- u
u. 0 (SHORT) LP+ 1 +
w
T+
.J :r
.. u
R+
R+
1 L + 2+
Lp + 1 +
R+
3 +
2 +
.J <(
<(
0
z
<(
11
3 +
::e 0::
0:: a. (SHORT) 2+
T+
O a.
:r
~
12
i
~ (LONG)
(f)
z
0
~
u
-0
zz
0
-Iu
z
::>
LL.
13
(LONG)
R+
4 +
3 +
2L+
B +
Lp +
T+
R+
4 +
3 +
2 L +
1 2 +
Lp +
R+
2L+ 5 +
LP+ 4+
1 L +
A+
LP+
T+
R+
2 L
Lp
1 L
1 3
Lp
R+
1 L + 6 +
LP+ 5 +
(SHORT) T+
R.-+
7 +
A+
15
6 +
(SHORT} T+
14
>-
w
>
R+
7 +
6 +
,.
R+
1 6 +
PC+ 2340+
7 +
2AK+ 2LHKt 2P OK+
PCP+ BR++
2 L +
I-
Ww
(/)
w
2L +
B +
LP+
16
Zo::
LB+
0
-o (LONG) 1 6 +
0
~z
<(
u
0
z
+ 5 +
+ 4+
+
+
+
R+
1 L + 6 +
Lp + 5 +
B +
R+
1 6 +
7 +
M+
MSP +
0::
...I
A+
~
LBP+
+
CR+
s
Lp +
LB+
1 6 +
2 3 40 +
L BP+
2 3 4S + SP+ CR+
9 +
1 2 + 13 +
1 L +
B+
IL+
+
ss
87
CD+
r- .
ACTION AT FIELD ST A TIONS LOCKED OUT
BY iNDICATION CODES
When an indication code starts action, the office re-verses the polarity of the line circuit. At all field stations
that are not transmitting, the R relay reverses. lL, 2L,
1, LP, LB, and LBP pick up in sequence. Then lL releases
and picks up CD. Then LP, LB, LBP, 1 and CD release
in sequence. iL remains up and R remains reverse.
When the indication code completes, normal polarity
is restored on the line circuit, and the R relays are posi-- ·
tioned to normal. lL picks up over 2L (C3) and 2L is
deenergized. LP, LB and LBP pick up in sequence. Re-lays 2L, LP, LB, LBP and lL release in sequence, and all
field stations and office equipments are reset to their
normal conditions at about the same time.
OPEN OR SHORTED LINE CIRCUIT
In case the line circuit breaks open at some point, the
office and all field stations up to the line break continue
to operate normally. However, the field stations beyond
the break act as described above for reversed line polarity
and are inoperative.
A line fault short--circuit may reverse many of the field
line relays. The equipment action at those stations so
affected will be as described above for reversed line polar-ity, and those stations will not be able to respond to
either controls or indications as long as the short--circuit
persists.
The equipment will automatically reset to normal when
the open or shorted line condition is corrected.
A milliamm,eter is provided in the line circuit and
placed on the control machine. This meter will indicate
any current which is not normal.
88
I
---,,.~ -
-•
IRREGULAR OPERATIONS DUE TO EQUIPMENT
TROUBLE
In case a unit cannot complete a code because of code
equipment circuit trouble, or due to some external inter,
ference, the unit will be farced to reset by the release of
relay LBP. At the office, if the drop,out occurs before
the 8th step, ST holds the storage and provides repeating
codes until cancelled by the cancellation button. If the
drop~out occurs after the 8th step, the storage already
has be;n cancelled and no repeat coding occurs.
In the field, the ST stick circuit is held during coding
over LB (AS) and_ MSP (A2 ap.d A6). In case of an in,
complete code, LB drops out and reverses ST to maintain
the storage, which produces repeated coding. If the code
progresses to the point where the station is selected, relay
SS is operated, which holds off code repeats whenever
the office ot other field stations have codes to transmit.
However, if the repeating code does not progress to where
the station is selected, a thermal relay CO is provided to
interrupt the repeating· codes periodically. When the
thermal relay is heated sufficiently, it opens the M relay
circuit, thus removing that station from the line. The
line is then available for use by other stations. When the
thermal relay cools, it restores the faulty station to the
line for a few more codes, until again eliminated by the
thermal relay. This periodic coding continues until the
fault is corrected.
The code equipment circuits have been so designed as
to require proper operation in order to obtain complete
codes. Any circuit that may become faulty will force the
equipment to reset before completion, with the resultant
repeated coding. The point of fault may be determined
by studying the type of action obtained under the irregu,
lar condition.
89
.
'
LINE CIRCUIT COMBINATIONS
It has· now become almost standard practice to use
one pair of line wires for the Time Code Control System
and for communication purposes. The Type L Form 506
System~ described in this manual, has been designed to
permit this joint use of one pair of line wires.
Western Electric Selectors type 160, which are the
ones most frequently encountered on railroad telephone
circuits, may be operated on the same pair of wir~ as the
506 system. Suitable lockout circuits have been designed
so that only one type of code (Selector or Time Code,
but not both) is on the line at a given time. When a Code
Control System is installed on an existing dispatchers
line, it is usually practical to decrease greatly the number
of selectors on the line; first b~cause there will then be
less need for calling operators, and secondly· because a
"Step in a Control Code" can usually be made available
· for calling an operator.
Since ·the field line relays of the Form 506 system are
connected in multiple and since there are no series coils
or contacts in the line circuit, it is evident that the line
1nay be simplexed or phantomed or both simplexed and
phantomed.
Alternating or carrier currents may be superposed on
the line wires on the 506 system. These frequencies may
be used for additional telephone and telegraph channels,
for continuous control and indication of special functions
Sllch as manual block signals or for the provision of con~
trols to and indications from separate line sections or
groups of field stations.
With all of these possible combinations existing, it is
evident that it is not within the scope of this manual to
90
provide detailed descriptions of these combinations. The
gen~ral practice is to furnish a line circuit drawing indi,
vidual to each inst a 11 at ion, the details of which are
determined by discussions and agreements between the
purchaser and the manufacturer. These drawings may be
understood readily by those familiar with the Form 506
Time Code Control System and with the theories of tele,
phone and telegraph communication.
In general it may be said "that if an existing communi,
cation line is strong enough mechanically, the same pair
of wires may serve as a line circuit for the Time Code
Control System. If no existing communication line is
suitable to permit the Tirne Code Control System to be
superposed, the new, and stronger line put up for the Time
Code Control System may have other facilities superposed.
91
..
'j!HEN REQUIRED
----,
MILLIAMMETER
I I A3 •
I ~....:--,
r-...._---1
\F"'---~Ll~-~·~II.UIJ&liU,.().lL~l-----;p-~li--~l..,_____..,......
I
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L2
ZMF
ZMF
ZMF
...,.......
I ,c
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I 3c
~
C&
....
R6
...------,---~----,----;-----.....;.--~
,
89
J~t/'-
B~
TY.PICAL PANEL
TK
USED
WHEN
FR
I
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LBP
18)--i~h
C&
581)---'--4-""-....-!....___ __.
I
useo
~o
01 ~:~:::~ISH
UNIT & TERMINALS
WHEN 0Es1R£D
wH1Le
coDING
Dt
c
=:~fft~~ I .·I
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8
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Nt I B~--1-~·
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LEAD STORAGE
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POWER OFF
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APPROACH
EB~
POK
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~ B
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AK
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AS SPECIFIED
OFFICE: LINE: - CODING
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EB~
:/
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LIGHTNING
ARRESTERS
TELEPHONE
OR
LOUD SPEAKER
L _ _ _J
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LINE
CIRCUIT
E8 > - ~
~NWEK
I
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DDtT,oN,
CONTROL!
WHEN
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REQUIRED WHEN
$£LECTORS USED
I
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84
CANC£LLATIO'N
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BUTTON
STARTING
BUTTON
8
INDICATION
234D
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RELAYS
---'--------'------+----,..;,__-----'-'---.1•
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DURING INOICATIONSLIN£ CURRENT INCREASE
OPERATES"' R• REVERSE
LIN£ CURR£NT DECREASE
OPERATES • n• NORMAL
~
TERMINAL
2L
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- - . . . c1e
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RECTIFli:R SNUBBING RELAY
FOR SLOW RELEASE.
.
......,,,,,.,,, RESISTOR
--; I--
CONDENSER
-D-
ORDINARY
=8=
DOUBLE COJL RELAY
RELAY
1
I
1.·
B~
INSTRUCTION
CIRCUIT DIAGRAMS
FIELD L C S , &. S UNITS---·-···025-47..SH.2
PYRAMID UNIT5 &. LINE CIRCUIT D2S47-SH.3
TIME CHART..._, ......,,--·---02547-SH.4
TEST S£T ____ .. _ _ _ _
. -D2W7-$K.S
C,
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BY
EXTINGUISHED
STARTING BUTTON
B~
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BUZZER
BEL
CUTOUT
BUTTON
TUNED
ALTERNATOR
3
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ALTERNATE
BY DASHED
CIRCUIT
LINES~
S OWN
5,5.E
1
1
10
RELAY
PAMPHLET -U5t2Z
I
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c
'<--41,--_ _ __._ _ _
1~----------------t--:-+----+--,-t-----ir---i---i-'•8~·~
NEUTRAL RELAY CONTACTS
I
I
8~--~..J 1
ds;.--- __ J INDICATIONS
RELEASE RELAY
STICK POLAR
CONTACTS
BELL
CUTOUT
BUTTON
42
__......,. OTHER MU1.TIPLE C0¥NECTIOJS
SLOW
ALK
R~K
I
- - - ( Bii
b-
RWK
LHK
-,.,._,,- CONN,CTIONS TO ALL
STORAGE UNITS
t .
--1-
----------,-----------.~•
TK
---'----'----'---------'---,~z
l~c
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l ~8
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TERMINAL
MULTIPLE
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SYMBOLS
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l
---'----------'i---------,----..e2
LOCAL BATTERY .
O CELLS LEAD STORAGE
...-,,.._..,.
AS
.1
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co I
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TELEPHONE FILTER
WHEN REQUIRED
I
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L__ _ _ _ _ _ _ _ _ _ _ _
I
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LLEPHONE
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8
TYPICAL WAYSIDE
CONNECTIONS
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11-i-!--1-.-:-0- - - - - ,
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LINE-CODING-STORAGE UNIT & TERMINALS
r------M--1
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ALTERNATE ARRANGEMENT.
TRACK INDICATION STICK· RELAY
-
NOTE·-
coNNEcnoNs SEE
RUCTION
SH, 3.
PAMPHLET-U!.122
CIRCUIT
DIAGRAMS
OFFICE LC & S UNITS ....... _..- ...........-DH47-SH. t
PYRAMID UNITS L LINE CIRCUIT 02547-SH.3
TIME CHART ...----·----·---·-..---,02547-SH.4
TEST SET---.. - - - - - - - - -..--02&47-SH.5
WIRING
DIAGRAMS
OF'FICE LC UN1T--...-Cl3112-5H.
FIE1.0 LC:5 UNIT..........-Cl312-5H.
FIELD $ UNIT·-·-···..···... Cl3112-5H.
FIE1.0 PYRAMID UNIT Cl342-$H,
$23
&25
524
521
FIELD LINE-CODING-STORAGE UNIT
CIRCUIT DIAGRAMS
TIME CODE CONTROL SYSTEM
TYPE L
F'ORM 506
35 STATION BASIS
• U.S. /j, S. CO., .SrtlS:SVAU, p,.·,
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SH. 2 ;~
FIELD. LCS UNI
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SCHEMATIC
:"it
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·iON Of
UNITS SERIES CIRCUITS.
SECOND
SERIES
or
LINE CIRCUIT DIAGRAM
2')-~~~~~~~-:-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-=.
STATIONS.
1--
SEE NOT£ ""A.SH.2.
33
ONE OF
.SEC.ONO GROUP
STORAGE UNITS
OFrlCE LINE-COOING!
.
UNIT T£RMINAL~-Stt;~1
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PYRAMID AND
LINE CIRCUITS
RELAY OPERATION SYMBOL
Z34ST
M
ARMATURE
PICKS UP
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CONTACTS
CLOSE
PC
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INTERPI
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R
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EQUIPMENT
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AND
RELEASED
BY
STARTING
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1
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STATION
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FIELD
EQUIPMENT
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R
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CLOCKWISE
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END
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GA
.... ,-'
.-
•• 111---1-----.......
s
.111------+-------------------------i,----------""'·
D
.. _... __ ............. 18 LONG .... _,, •• _ REGIST1
co
IS THERMAL RELAY FUNCTIONING WHEN FIEL
STATION REPEATS CODES APflAOXIMATEt.Y 4i, SE
IN lO SECONDS ANO CUTS OUT AGAI
RU,TOA[S
IN 10 SECONDS.
CIRCUIT
4
STATION
6
7
FIELD
EQUIPMENT
234
DIAGRAMS
OF'F'ICE EQUlPMENT ••••••••••• _--.................--·-·-......-D2547
Fl[LD
EQUIPMENT ......... ___________,_... Q2S47
PYRAMID
TEST
UNIT.1-LINE C1RCUIT------D2So47
SET.-....- ..- - - - - - - · · - · - - - - D 2 S . 4 7
ti
CR
16
·--" ·-------""·
CAll-----fll
MSP
co
(E)
RESET ..... --,-·...- .. _
NOTE:-
2L
LP
LB
LBP
SS
1
s
,11--+---H
...
A
SPECJAL .............- ..... -.-·--·---..- ••12 ........--.-APPRC,
t.ErT SIGNAL .........,..- -..· - - - - -1 3 , , - · - - - - SIGNAL
CALL-OH SIGNAL.... _ .. _ _ _ _ 14------POWtR
RIGHT SIGHAL .... ___ ,.,. ___ ..,... _1s ...... _.. _ .. __ .s1GNAL
STOP SIGNAL . .--,. . --,-::!!! ~:::T~~,.:i~
T
1L
T
2
3
I',
CD
~£
M
CLOCKWISE:
l1L L,,j,off-,ffo--------,-""""\11L
2L
7 ...
CR
ti
_._·-···-·os"
ES
:~~,;c~~s:ic.iEc.
M
"\
•,Y.---+---+---+-----+---+..o;-.111--+------+--~,c•
a
JI
REVERSE SWJTCH-......... __ .... _,_ •. t ' - - - -..-SWITCH.
CAN START
.i--+-h,
16
·~r :
I
,4
II
I
II
NORMAL SWITCH ...,-... - .. _ ........- ... 1 ......................... SWITC
SPECIAL--..--.-·... _ .. ________ 10 ...........
T
i!:coNO CODE
..... f\
'
4
1
INDICA
DETERMINATION~ 2---:-,"STATION
ST
2LI
1
2
3
CD
A
B
fA
GA
s
D
MSP
co
(E)
FUNCTION.{ lWSR
CONTROL 2lHSR
RELAYS
.
LINC ENERGIZED LINC DE-EHERGIZED -
I
TYPICAL INDICATION CODE
CR
I
I
IMPULSE
II
~
I
I
1
I
I
I
I
I
I
I
I
I
I
~ 20 - - 40 - - 1 SEC.--20 - - 40 - - ZSEC:.-- 20 - - 40 - - 3 SEC:.-- 20 - - 40 - - 4 SEC:.-- 20
IL
2L
LP
LB
LBP
SS
I
I
I
.
M
-
I
TYPICAL CONTROL CODE
ST
R
A!U
CODE INTERPRETATION
ZPOK
M
I
I
I
I
I
I
I
I
I
I
I
0 - - - 2 0 - - - 4 0 - - 1 SEC.-- zo - - 40 - - z SEC:.--20 - - 40 - - 3 SEC.-- 20 - - 40 - - 4 SEC.--- 0
I
PROGRESSION
IN
CONTROL CODE
2AAU1"_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1RWK
2AK
~
I
CODE
RELAYS
11
2LHK
I
TO
RELEASE
2f4Gs
2340
2RHK
I
SEC.
SLOW
STATION
ZRHK
I
TO
2F
2LHK
I
y12
.SEC.
1TK
8UTTON
2POK---t--..,.,.. ...,......._.,.,,_,.............._ ..._________________________________________________________________________________"'J12Pok
SCALE IN CYCLES
"e""o"'c"'Y"'c:L-£""s....~1'"s"'E"c"o"°N~O-·-
Ste.
y•o
y'•o
RELAYS
LOCKOUT (LONG) •• _ .. ,_.. _____ 1--·--·-.l.OCKOI
·1NwK~--1,-----------------------------------------------.. .-----------------------------------------,,,.-w-.-i---------------------,NWK
2LHK1Jlo---------------2AK'
1RWK
VtzO
REGULAR
REPRESENTED
APPROXIMATE.
~
E
234011-_ _ _ _ _....,_2340
!!!
LINE RELAY.s
TIMING
,2
spfr-c•ot:::::::::::::::::::::::::::::::::::::::::i~:::::::::::~::::i~~:
TIMING
PICKUP
!::
;
23c1----,-,.-.1'~----------------------t------+-....,2,. s
. aF·ll----otl.
2340
Hsll-_ _ _ _ _..._
0ESCRIPTION
1JI
sPllr-----....
!:R
,.11----,..;,;::::;::~;:::::::::::,:-:;::~~!
=
RELAY OPERATION
2~
LINE CIRCUIT ACTION
......- - - - ,
2RHSR
2USR
=============:::];;I=~==
FOR CONTROL CODE
--~--
CONTROL
LOCKOUT
NORMAL
SWITCH
foFFICE
LINE
RELAY
MAGNETICALLY
ENERGIZED
ANO
~TUCK
AND
..----,
13
CLEAR LEFT
SICNAL
14
CALL-ON
SIGNAL
15
-----------------~--
.
£QUIPMENT
RESET
,----,
INDICATION
LOCKOUT
'---~--'
STATION 234 SELECTION
FOR INDICATION
CODE
SHOWN
12
SWITCH
NORMAL
ABOVE
'--'-'"'--'14 15
APPROACH
LEFT SIGNAL
OCCUPIED
CLEAR
, - - - - - - - - - - C O D £ LINE
IIS
LINE
INDICATION REGISTRY
AND RESET
-coo£
ENERGIZtD
SHUNTED
CLOCKWISE.
~JELD
LINE
JoFFtCE
LINE RELAY MAGNETJCALLY STUCK AND COUNTER-CLOCI\WJSE.
LINE JUU.AY DE-ENERGIZED AND COUNTER ... Cl.OCKWISE.
1_,IELD
IU:LAY
SHOWN ABOVE
======::;,::------------
\:~:::
WAYSIDE 2RL:G:P:R
2
RELAYS
1LR -•••-··-----,,
1
2AR-----------~,
2POR--LINE CIRCUIT ACTION
CLOCKWISE.
0254
CIRCUIT DIAGRAMS
BASIS
SH.4
TIME CHA
t . " . .. t.•-. ... ,:,
,::,,.,.,.c..
• ,.,
•"
\••,""'•l .,.,., .., ""6
,H
:;o,..,(r r•o .. ,
"'-" ..
•o
r.1111
·~ ~, ..... , ••• .. .. c ... ,,. .. ( o,
,,.(.
l.AC.,.
r ••• ...
r~ut
•t. .l'l
•
.,, •
"''•-t
l'll'" ,,,.,;....
, .. :; .....
HI
41 t."'I
,.,.,
.....
r_ .. tc,
• .. (
I
l I
I
I
I II
I
I
!
I
i
I
I,
!
•r <1·~'""'-
'!.Er
#4/'W:•
~r;::.; ~;;::·-:;Jt.z~:;:{J.:,:i;::·7?S
I!•
1r p,-• .,1.,
___ - · _ _ _ - - - · - _
~r1 rf!"f~ ,~ ..
5,t,r. Y1r.'dyk1 -·- •
l?i,.-.a
,5:,...-.c
J".'T<!! .~Jni~
r-er/s.,~n nv,d. ~...
OFFICE
l i
..,-:;co • ,~=t
· -.-. .. ~c r,c.,.
UNITS
SH. 7A
ALT(RNAT£. J-.RR.1,;NGEMENT
TRACK INDICATION $TICK. REt..AY
liJ..:•C,'N'JL 11rpt (lv•I·
, ... , .
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