RTK UC625 series User manual

1
UC625 Compact Alarm Annunciator Rev 17

2
REV DATED DESCRIPTION AUTHOR APPROVED
10 01-05-07
Option M4 added to provide Lamp / Audible
Test
P.Cartmell T. McLeman
11 22-05-07 Option M3 Response Time Spec P.Cartmell T. McLeman
12 29-10-07 Repeat Relay Ratings clarified P.Cartmell T. McLeman
13 02-11-07 Signal Supply Monitoring & Terminals with
locking screws added
P.Cartmell T. McLeman
14 23-07-08 Sleep Mode Switch wiring clarified P.Cartmell D. Fishkin
15 31-07-08 Powered Inputs & Switch Settings Clarified P.Cartmell D. Fishkin
16 14-01-09 ASIC versions clarified P.Cartmell D. Fishkin
17 14-04-09 Wiring Drawings updated P.Cartmell D. Fishkin
18 06-06-11 Isolation Diode details added to sleep mode P.Cartmell D. Fishkin
© RTK Instruments LTD 2004
The copyright in this work is vested in RTK Instruments Ltd and this document is issued for the
purpose only for which it is supplied. No licence is implied for the use of any patented feature. It must
not be reproduced in whole or in part, or used for tendering or manufacturing purposes except under
an agreement or with the consent in writing of RTK Instruments Ltd and then only on the condition that
this notice is included in any such reproduction. Information furnished is believed to be accurate but no
liability in respect of any use of it is accepted by RTK Instruments Ltd.
Important Note
The UC625 system described herein operates on a logic voltage of 24VDC and as
standard 24VDC is used for the field contact supply voltage.
External power supplies using higher voltage AC/DC primary sources and optional high
voltage field contact voltages may be present if this is the case please ensure the
necessary precautions are taken

RTK Series UC625 Annunciator
3
Table Of Contents
Table Of Contents................................................................................................................3
Figures..................................................................................................................................6
Tables...................................................................................................................................7
Introduction..........................................................................................................................9
Model Number Description ...............................................................................................10
Option Codes..................................................................................................................................... 10
System Description and Features ....................................................................................11
General .............................................................................................................................................. 11
Alarm Card......................................................................................................................................... 11
Reliable Annunciation........................................................................................................................ 11
Supply/Pushbutton/Relay Card (SPR)............................................................................................... 11
Power Failure Monitoring................................................................................................................... 11
Serviceability...................................................................................................................................... 12
No Special Service Tools Required................................................................................................... 12
Inputs & Outputs................................................................................................................13
Customer Connections ...................................................................................................................... 13
Annunciator Inputs............................................................................................................................. 13
Optically Coupled Inputs.................................................................................................................... 13
Signal Duplicating Relays.................................................................................................................. 13
Response Time.................................................................................................................................. 13
Common Alarm Group Relay [GP] .................................................................................................... 14
Reflash Function................................................................................................................................ 14
Dual Audible Alarm Feature............................................................................................................... 14
Dual Horn Relays [HNA-HNB]........................................................................................................... 14
Dual Power Monitoring Relays .......................................................................................................... 14
Mechanical Details.............................................................................................................15
Alarm Card......................................................................................................................................... 15
SPR Card – Supply / Pushbutton/Relay............................................................................................ 15
System Assembly .............................................................................................................................. 15
UC625 Dimensions............................................................................................................................ 15
Unit Depth.......................................................................................................................................... 15
Sequences..........................................................................................................................16
Summary............................................................................................................................................ 16
First-up Sequences............................................................................................................................ 16
Automatic Reset................................................................................................................................. 16
Non-latch Sequence (No lock-in)....................................................................................................... 16
Reflash Feature ................................................................................................................................. 16
Ringback Sequence........................................................................................................................... 17
Two Pushbutton Operation................................................................................................................ 17
Status Only Operation ....................................................................................................................... 17
Option M4 .......................................................................................................................................... 17
Sequence Configuration and Tables................................................................................18
Manual Reset ISA-Sequence M ........................................................................................................ 18
Automatic Reset ISA-Sequence A.................................................................................................... 18
Non Lock-in Function ISA-A-4 Sequence.......................................................................................... 19

4
Ringback ISA-R Sequence............................................................................................................... 19
Automatic Reset First-up ISA-F1A Sequence................................................................................... 20
Manual Reset First-up ISA-F2M-1 Sequence.................................................................................... 20
Status Only ISA-A-4-5-6 Sequence................................................................................................... 21
Features..............................................................................................................................22
Input Configuration ............................................................................................................................ 22
Signal Duplicating Relays.................................................................................................................. 22
Repeat Relay Mode Of Operation ..................................................................................................... 23
Input Follower .................................................................................................................................... 23
Logic Follower.................................................................................................................................... 23
Operation of Repeat Relays During Test........................................................................................... 23
System Test....................................................................................................................................... 23
Disable Horn On System Test Option “DHT” (Model Suffix Code M1).............................................. 23
LED Indication.................................................................................................................................... 23
Dual Audibles And Dual Horn Relays................................................................................................ 24
Integral Horn Disable......................................................................................................................... 24
Auto-Acknowledge Feature ............................................................................................................... 24
Common Alarm Relay........................................................................................................................ 25
Reflash Option................................................................................................................................... 25
Input Follower. ................................................................................................................................... 26
Logic Follower.................................................................................................................................... 26
Sleep Mode........................................................................................................................................ 26
1. Specification.............................................................................................................26
Optically Coupled Inputs.................................................................................................................... 27
Outputs .............................................................................................................................................. 27
Pushbuttons....................................................................................................................................... 28
General .............................................................................................................................................. 28
Installation..........................................................................................................................29
Cut-out Dimensions ........................................................................................................................... 29
Cabinet Fixing.................................................................................................................................... 29
Channel Numbering........................................................................................................................... 30
Connection Details............................................................................................................................. 31
Aux Supply Option............................................................................................................................. 32
Signal Supply..................................................................................................................................... 33
Signal Supply Monitor Relay.............................................................................................................. 33
Signal Supply Options ....................................................................................................................... 33
Earthing.............................................................................................................................................. 33
Remote Pushbutton Connections...................................................................................................... 33
Standard Inputs Connections ............................................................................................................ 35
Powered Inputs @ 24VDC................................................................................................................. 36
Higher Voltage Powered Inputs......................................................................................................... 37
Sleep Mode........................................................................................................................................ 38
System DIL Switch Location and Functions....................................................................39
DIL Switch Functions On Alarm Cards.............................................................................................. 39
Identifying Card Types....................................................................................................................... 40
Alarm Card Input Response Settings STANDARD VERSIONS ...................................................... 41
Alarm Card Input Response Settings M3 / M4 OPTION VERSIONS................................................ 42
Alarm Card Input & Sequence Settings (Set In Pairs)....................................................................... 43
Alarm Card Relay And Horn Settings (Set In Pairs).......................................................................... 44
DIL Switch Settings SPR Card .......................................................................................................... 45
SPR Card Horn, Relay And Pushbutton Settings.............................................................................. 46
Automatic Acknowledge Timer (Located On SPR Card).................................................................. 47
Internal Horns Disable (Located On SPR Card)............................................................................... 47

RTK Series UC625 Annunciator
5
Maintenance.......................................................................................................................48
No Special Tools Required................................................................................................................ 48
Legend Plate Removal ...................................................................................................................... 48
Film Legend Engraving...................................................................................................................... 48
Alarm Card or SPR Card Removal.................................................................................................... 48
Super-Bright LED’s............................................................................................................................ 48
Fuse replacement.............................................................................................................................. 48
Expansion Units.................................................................................................................50
Master and Expansion UC625 Units ................................................................................................. 50
Options...............................................................................................................................53
Option 00 Horn Disable On System Test ......................................................................................... 53
Option 01 Lamp Test Instead of Functional Test............................................................................... 53
Option 02 Ringback Horn Disabled ................................................................................................... 53
Option 03 ISA R12 Sequence............................................................................................................ 53
Option 04 Response Times............................................................................................................... 53
Option 05 Lamp / Audible Test.......................................................................................................... 53
Multiple Option Codes ....................................................................................................................... 53
Trouble Shooting Guide....................................................................................................54
Other RTK Products ..........................................................................................................58
Card Switch Settings Required To Set Alarm Sequences ..............................................59

6
Figures
Page No
1 Example Of A 12 And 20 Way UC625 Alarm Annunciator 8
2 Panel Fixing Arrangement 29
3 Channel Numbering 30
4 Typical Connection Details 31
5 Optional Remote Pushbutton Connections 33
6 Standard Signal Input Connections 33
7 24VDC Powered Signal Input Connections 34
8 48/110/250VAC/DC Powered Signal Input Connections 34
9 Sleep Mode 35
10 Alarm Card Showing DIL Switches 36
11 Alarm Card DIL Switch details (SW3 and SW5) 37
12 Alarm Card DIL Switch details (SW4 and SW6) 38
13 SPR Card Showing DIL Switches (Supply, P.B.’s and Relays) 39
14 SPR Card DIL Switch details (SW5) 40
15 Signal Supply Fuse Location 42
16 Fuse Location For Systems Using Aux. 24VDC Supply 42
17 UC625 Master & Expansion Rear Terminal Views 44
18 UC625 Expansion Units with Ribbon Expansion Sockets 44

RTK Series UC625 Annunciator
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Tables
1
UC625 Dimensions
15
2 ISA-M Sequence 18
3 ISA-A Sequence 18
4 ISA-A-4 Sequence 19
5 ISA-R Sequence 19
6 ISA-F1A Sequence 20
7 ISA-F2M-1 Sequence 20
8 ISA-A-4-5-6 Sequence Status Only 21
9 Input Configuration 22
10 Repeat Relay Coil State 22
11 Repeat Relay Contact State 22
12 Repeat Relay Mode Of Operation 23
13 Repeat Relay Operation During Test 23
14 Horn Drive Signal Configuration 24
15 Horn relays Contact State 24
16 Integral Horn Enable / Disable 24
17 Auto Ack. Timer Settings 24
18 Common Alarm Signal Enable 25
19 Common Alarm Contact State 25
20 Common Alarm Reflash Option 25
21 Common Alarm Signal Mode Of Operation 26
22 Cut-Out Dimensions 29
23 Power Connections 31
24 Optional Aux Supply 32
25 Pushbutton Options 32
26 Alarm Card DIL Switch Functions 36
27 Alarm Card Input Response Settings 37
28 Auto-Ack Timer (Located on SPR Card) 40
29 Internal Horns Disable on SPR Card 40
30
Switch Settings PER Alarm Sequence
51

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INSTRUMENTS
TEST
MUTE
RESET
ACK
SUPPLY 1
SUPPLY 2
SUPPLY FAIL
AUX DC
SUPPLY FAIL
UC625
MAIN DC
UC625 RESET
ACK
MUTE
TEST
SUPPLY 2
SUPPLY 1
INSTRUMENTS
Examples of a 20 and 12 way UC625 Alarm Annunciator
Figure 1

RTK Series UC625 Annunciator
9
Introduction
The RTK UC625 Series Alarm Annunciator system is designed to give LED indication of an alarm
condition, where a high degree of reliability and flexibility is required.
Each system comprises a compact cabinet, removable legend plate, universal Alarm Cards and a
Supply/Pushbutton/Relay (SPR) Card which gives maximum annunciator density whilst maintaining a
practical legend area and neat front panel appearance.
DIL switches, situated on each of the Alarm Cards permit easy selection of annunciator sequences as
listed in the ISA Publication “Alarm Sequences and Specifications S18.1 – 1979 (R1985)”.
As the system is fully field-programmable on a per pair of alarm basis, the operating specification, of
both alarm sequence and function, can be changed during commissioning, or at a later date after the
equipment is installed. This means that stocking requirements may be minimised, since all annunciator
cards are interchangeable.
Reliability of operation is increased over conventional annunciators by the use of application specific
integrated circuits (ASIC's), which are capable of complete system control. When the annunciator is
initially switched on, control is arbitrarily allocated to any one of the ASIC's on any of the Alarm Cards,
hence the annunciator requires no control or master module, failure of which could jeopardise the
whole system.
If the Alarm Card is removed or an ASIC goes faulty then control is randomly allocated to another
ASIC on another Alarm Card, hence the worst fault that could normally occur is the loss of one card.
The use of ASIC's also results in a very low component count, again improving system reliability.
The UC625 features an integral, dual power supply capable of accepting a supply voltage from either
88-265VAC OR 88-360VDC which allows the user to connect the unit directly to a main and aux
supply to provide redundant operation.
As an option, if specified at time of order, the second supply voltage can be manufactured to allow
direct operation from an Aux.24VDC Supply Voltage in the range 19 to 31VDC.
As standard an internally generated 24VDC is used as a signal supply voltage, which is used for
distribution to the associated field contacts. The 24VDC signal supply is designed to be present if
either the primary or secondary supply is available to ensure 100% redundancy.
Note:- When using the direct powered input options the signal supply voltage is derived from outside
the unit, by others, and redundancy is therefore dependent on the signal supply voltage being
available at all times.
On systems supplied after January 1st 2008 the signal supply voltage is provided with a monitor relay.
Two alarm channels are dedicated to monitor the dual supply Inputs and alert the operator if there is a
loss or failure of either.
Accessibility for servicing is excellent, being accomplished from the front of the panel with only a
screwdriver required to access the alarm or Supply / Pushbutton / Relay card.

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Model Number Description
UC625 = Model no prefix
** = Number of available alarm channels [Not including the 2 power failure alarms]
** = LED colour RD = Red (Standard)
H = Input supply 1 universal (88-360VDC or 88-265VAC)
** = Input supply 2 specify option H or L
024D = 24VDC signal supply voltage OR
Options for 48/110/250VAC/DC signal supply inputs
R = Individual channel signal duplicating relays fitted
MODEL
NO OF
ALARMS
LED COLOUR SUPPLY 1 ** SUPPLY 2 SIGNAL SUPPLY
REPEAT
RELAYS
UC625
12
RD = Red
YL = Yellow
AM = Amber
GN = Green
WH = White
IN = Intermixed
H = Universal
88 to 265VAC
or
88 to 360VDC
Optional
L = 24VDC
OR
H = Universal
88 to 265 VAC
or
88 to 360 VDC
Standard
R = Repeat
Relay
Option
Fitted
16
024D = 24VDC
20
Optional Externally
Powered Inputs
24
28
32
048 = 48VAC/DC
36
110 = 110VAC/DC
40
250 = 250VAC/DC
Typical Model No
UC625 40 RD H H 024D R – M*
M* Option code see below)
Please note:- If more than 40 ways are required as a single system expansion UC625 units can be
connected via the expansion ribbon bus connector as detailed later in the manual on all units shipped
after August 2004
Option Codes
These Codes are added as a suffix to the Model No and MUST be specified at the time of ordering.
M1 = Horn disabled on System Test
M2 = Modified Ringback sequence, disabled ring back audible and lamp test in place of system test.
M3 = ISA R12 Ringback sequence, disabled Ringback horn, lamp test in place of system test and
response time changed to 5mS trip 5S pre-alarm.
M4 = ISA R12 Ringback sequence, disabled ring back audible, lamp test in place of system test,
response time changed to 5mS trip and 5S pre-alarm and combined Lamp / Audible Test
pushbutton function.

RTK Series UC625 Annunciator
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System Description and Features
General
The units can be manufactured in a range of sizes to suit individual applications. All units are designed
to be 4 alarm ways high but the number of windows wide is variable. This allows RTK to provide
systems suitable for 12, 16, 20, 24, 28, 32, 36 or 40 channels and all units are provided with two
additional channels used for monitoring the two integral supplies, Supply 1 and Supply 2
The annunciators are built up using variable size top / bottom plates, universal side plates to give a
basic panel mounting framework, a rear mounting motherboard and removable Legend Plate. The
universal Alarm Cards are of the plug in type and are easily accessed once the front legend plate has
been removed. The Alarm Cards simply plug into the motherboard, which also houses the terminals
for external connection by the customer. A removable legend plate is fitted over the front of the alarm
boards containing film legends, which identify the individual alarm channels.
Alarm Card
Each active Alarm Card controls four alarm points. The Alarm Card has an Application Specific
Integrated Circuit (ASIC), which controls the alarm ways. System control is arbitrarily allocated to one
of the ASIC's on any one of the Alarm Cards, obviating the need for a master control module. Each
Alarm Card is fitted with DIL switches, which are used to select the required features for each pair of
alarms.
Reliable Annunciation
The fact that all the cards are identical means that in the RTK Series UC625 alarm system there is no
master or controlling card, failure of which could jeopardise the whole system. System control is
arbitrarily allocated to any one of the alarm modules. Should this card be removed, damaged or fail for
any reason, another card will take over system control. This method of operation results in a system
with no single source of failure and multiple redundancies giving the most reliable form of annunciation
possible.
Supply/Pushbutton/Relay Card (SPR)
This card is fitted in the right hand side of the annunciator and has 4 pushbuttons to cover all system
functions and two “power on” LED’s. The four pushbuttons are:- System Test, Acknowledge, Mute and
Reset. The two green LED’s are used to indicate "Power On" for Supply 1 (main) and Supply 2 (aux.).
Power Failure Monitoring
The SPR Card is fitted with two power failure alarms, which are used to monitor Supply 1 and Supply
2 and provide full alarm capability when either supply is not present on the unit.
The two supply inputs provide FULL redundancy of operation so that failure of a single supply input
will have no affect on the overall operation of the unit.
The standard version which uses an internally generated 24VDC Signal Supply to provide a feed to
the field contacts.
Powered input versions rely on the customer generated signal supply being available at all times.
The Power Failure alarm channels are fixed at alarm sequence ISA-M and are therefore controlled by
System Test, Acknowledge and Reset Pushbutton inputs to allow full control over the alarms.
In sub station applications it is common for a number of annunciators to share a common set of
controlling pushbuttons, the pushbutton inputs can therefore be connected between units as required.

12
In addition to the full alarm capability each power failure alarm channel is also equipped with a Signal
Duplicating Relay to allow notification of power failure to 3rd party devices.
A volt-free contact is provided per supply input, which will change to abnormal on alarm and remain in
the abnormal state until power is restored.
The output can be changed to normally open or normally closed as required.
Please note the Signal duplicating contacts are not affected by the System Test pushbutton and act as
faithful slaves of the Signal Input.
Serviceability
All servicing is carried out from the front of the unit having first removed the legend plate.
The alarm boards are universal and thus fully interchangeable as required.
No Special Service Tools Required
A screwdriver is the only tool required to remove the legend plate to access the alarm and power
board, in order to replace or remove the circuit board to make adjustments to the DIL switches.

RTK Series UC625 Annunciator
13
Inputs & Outputs
Customer Connections
All connections to the alarm board inputs and outputs are made via quick disconnect, rising clamp, two
part plug-able connectors.
Annunciator Inputs
The standard Series UC625 Annunciator operates from either a normally open or normally closed
contact. Standard systems use an internally generated 24VDC as the signal supply voltage however
options exist, if specified at the time of order, to allow the user to use direct powered inputs:-
NOMINAL VOLTAGE MIN V MAX V
24VAC/DC 13 100
48VAC/DC 24 120
110VAC/DC 56 220
250VAC/DC 120 400
Please note:- The above min & max voltages are typical values in reality the inputs are designed to
withstand substantially higher voltages for prolonged periods under fault conditions.
As field contacts are often great distances from the annunciator it is advisable to run the contact
cables separately from circuits carrying heavy currents and/or high voltages so as to minimise the
effects of induced voltages. A transient filter is built into the input circuitry so that low voltage
interference will be ignored. Contacts may be continuous or fleeting, the annunciator can be selected
to lock-in fleeting alarms if required.
Optically Coupled Inputs
All inputs from alarm contacts and external pushbuttons are optically coupled. This method of
operation improves the system's tolerance to noise interference and allows operation from voltage
sources as standard.
Signal Duplicating Relays
Integrally mounted signal duplicating relays are provided per channel. The standard mode of operation
for the duplicating repeat relays is to activate when an alarm condition occurs and return to normal
when the plant fault has returned to normal. (Contact-Follower). Each pair of signal duplicating relays
can be set to operate as either normally de-energised or normally energised relays and the associated
contact can be selected as normally open or normally closed.
Response Time
Each channel within the annunciator can have a pre-defined min response time set to one of the
following times:- 5ms, 25ms, 50ms and 100ms using DIL switches mounted on each alarm card.
Unless otherwise requested at the time of order units are shipped with a factory setting of 25ms but
can be easily changed to 5mS, 50mS or 100mS as described later in the manual.
If the UC625 is supplied with a suffix M3 or M4 in the model number the response times will be 5mS,
25mS, 200mS or 5S as described later in the manual

14
Common Alarm Group Relay [GP]
Alarm channels can be connected to an internal common alarm group relay (GP), which is normally
used to indicate to remote equipment that an alarm has occurred in a local panel. The Relay output
contact state is set using LK3 on the SPR card to be either normally open or normally closed. The
contact will change state when an alarm occurs and remain in the alarm state until all faults have
returned to normal.
Reflash Function
After acknowledge if a new alarm occurs the relay will momentarily drop out and re-activate to indicate
that another alarm has occurred. The reflash function ensures that when monitoring the alarms from a
remote location, users are fully aware of alarm activity on the unit.
Dual Audible Alarm Feature
UC625 systems are supplied as standard with two integral audible alarms designated critical audible
and non critical audible. Each pair of alarms can be set to operate the associated audible.
Dual Horn Relays [HNA-HNB]
All units are supplied with dual integral horn relays one for critical alarms – HNA and one for non-
critical alarms – HNB. Each pair of alarms within the unit can be set to operate either or both of the
relays as required. When an alarm occurs the horn relay contact will change state and the contact will
remain in the alarm state until the ack or mute pushbutton has been pressed or the automatic ack
timer has activated. The Customer can disable the automatic timer circuit if required as described later
in the manual.
Dual Power Monitoring Relays
Two integral power monitor relays are provided as standard, one monitors the primary supply and one
monitors the secondary supply input. The power monitor relays are factory set to be normally
energised and will de-energise if the primary or secondary supply fails. Each coil of the relay can be
set to be normally energised if required and the relay contact can be set, using LK1 (Supply 1) and
LK2 (Supply 2) on the SPR card, to normally open or normally closed.

RTK Series UC625 Annunciator
15
Mechanical Details
Alarm Card
Each alarm card provides all common alarm sequences as listed in the ISA specification “Alarm
Sequences and Specifications S18.1 1979 (R1985”). The universal alarm card plugs into the edge
connectors mounted on the inside of the motherboard, the size of motherboard being determined by
the total number of alarms required.
SPR Card – Supply / Pushbutton/Relay
This module is the same size, shape and fixing as an alarm card and is equipped with System Test,
Acknowledge, Mute, & Reset pushbuttons necessary for all of the available operating sequences.
This module is fitted in the extreme right hand edge connector within the annunciator and is polarised
to ensure it cannot be placed into the wrong card slot.
System Assembly
Systems are supplied pre-assembled with motherboards used to match each system configuration (i.e.
number of ways high is always 4 x number of cards wide, plus a Supply/Pushbutton/Relay (SPR) Card
with 2 ways always used for power failure monitoring. The cards required (alarm ways divided by 4,
plus “Alarm Sequences and Specifications S18.1 1979 (R1985)”. Are plugged into the motherboard
and the appropriate legend plate is then fixed to the front of the unit.
UC625 Dimensions
NUMBER OF
ALARM WAYS
OVERALL SIZE
(H X W) MMS
CUT-OUT SIZE
(H X W) MMS
12 154 x 152 141 x136
16 154 x 180 141 x 164
20 154 x 208 141 x192
24 154 x 236 141 x 220
28 154 x 264 141 x 248
32 154 x 292 141 x 276
36 154 x 320 141 x 304
40 154 x 348 141 x 332
Table 1
Please note:-Cut-Out Dimensions have a tolerance of plus or minus 0.5 mm.
Unit Depth
All UC625 Units are 130 mm Deep

16
Sequences
Summary
From the sequence tables shown later in the manual, it will be evident that an alarm occurring causes
a flashing visual indication with audible.
Mute is used to silence the audible only.
Acknowledge stops the flashing and audible.
Please note:- If a new alarm occurs on an already acknowledged system, the horn will re-sound and
the new alarm will flash in accordance with the selected sequence.
Reset will return the alarm to the normal off state only when the unit has been acknowledged and the
associated alarm contact has returned to normal.
First-up Sequences
When a group of alarms is initiated, it is often important to know which of them was the first to occur.
This is achieved by having the first-up alarm flashing in a different manner compared to the
subsequent alarms. Three different first-up sequences are available F0, F1, F2 as detailed below and
in the following sequence tables. First-up operation should be used with care with the auto-reset
sequence and non-latch sequence as momentary alarms can cause ambiguity.
F0 The standard mode adopted by RTK Instruments, which indicates the first-up alarm by flashing at
twice the rate of subsequent alarms.
F1 In this mode subsequent alarms appear in the acknowledged state, hence they do not flash. The
audible device does not operate when subsequent alarms occur, unless still operating from the
first alarm. The acknowledge pushbutton will reset the first-up indication.
F2 In this mode all subsequent alarms do not flash, they will however operate the audible device. The
acknowledge pushbutton will reset the first-up indication.
Automatic Reset
In this mode, any signal contact which returns to normal after the acknowledge pushbutton has been
pressed will automatically reset. If the alarm contact returns to normal prior to acknowledge the alarm
will reset immediately after the acknowledge pushbutton has been operated.
Non-latch Sequence (No lock-in)
In this mode alarms will automatically reset as soon as the signal input returns to the normal state. It is
therefore possible that a fleeting alarm will occur and return to the off state without operator
intervention. Whilst the alarm is in the abnormal state the operator can silence or acknowledge the
alarm in the normal way.
Reflash Feature
In the standard mode, when an alarm has occurred and the acknowledged pushbutton activated, any
further changes of state to the alarm contact will not affect the alarm window display. With reflash
enabled any alarm that returns to normal and re-occurs will re-initialise the window.

RTK Series UC625 Annunciator
17
Ringback Sequence
This mode uses visual and audible signals to indicate that the alarm has returned to normal and the
operator can reset the alarm. When an alarm contact returns to normal the ringback circuit will pulse
the audible alarm and the associated LED will flash at approx half the speed of the normal alarm flash
rate. Ringback operation may be used with all but non-latched and auto reset sequences and operates
in the same way for all first-up sequences F0 to F2.
Two Pushbutton Operation
In certain circumstances using remote pushbuttons, it may be desirable to use only two pushbuttons:
Reset and Lamp Test. The Reset pushbutton is used to Acknowledge an alarm if the contacts are in
the alarm condition and to Reset it if the contacts are clear.
Status Only Operation
In applications where the user wishes to indicate the current status of plant machinery the channel can
be set to status only. In this Mode the associated LED will be either on or off as the Input changes
state.Example:- alarm normal = PUMP ON : alarm abnormal = PUMP OFF. Please note:-This feature
is only selectable in pairs ( Channel 1 & 2 or Channel 3 or 4 ).
Please refer to the last page of the manual for details of the switch settings required for each of the
following sequences.
Option M4
When option M4 is specified in the Model No a combined Lamp / Audible Test is provided in place of
Lamp Test

18
Sequence Configuration and Tables
Each pair of alarm channels can be configured to suit the operating sequence required, as listed in the
ISA publication “Alarm Sequences and Specifications" S18.1 1979 (R1985)”. Systems can be
configured with different features on each pair of alarms and there is no need to switch the power off.
Different operating modes can be selected using the on board DIL switches. The following tables show
the most commonly used examples.
Manual Reset ISA-Sequence M
PROCESS PUSHBUTTON VISUAL AUDIBLE
Normal OFF OFF
Abnormal Flashing ON
Abnormal Acknowledge ON OFF
Normal Reset OFF OFF
Table 2
Sequence features
1. System test simulates an abnormal plant state on all alarms
2. Alarms must be set to lock-in of momentary
3. Manual reset of acknowledged alarms is only possible after process conditions return to
normal
Automatic Reset ISA-Sequence A
PROCESS PUSHBUTTON VISUAL AUDIBLE
Normal OFF OFF
Abnormal Flashing ON
Abnormal Acknowledge ON OFF
Normal OFF OFF
Table 3
Sequence features
1. System test simulates an abnormal plant state on all alarms
2. Alarms must be set to lock-in of momentary

RTK Series UC625 Annunciator
19
Non Lock-in Function ISA-A-4 Sequence
PROCESS PUSHBUTTON VISUAL AUDIBLE
Normal OFF OFF
Abnormal Flashing ON
Normal Before Ack OFF OFF
Abnormal Acknowledge ON OFF
Normal OFF OFF
Table 4
Sequence features
1. System test simulates an abnormal plant state on all alarms
2. Alarms should be set to non-lock-in
3. Alarms will automatically return to the off state as soon as the input returns to the normal.
Ringback ISA-R Sequence
PROCESS PUSHBUTTON VISUAL AUDIBLE
Normal OFF OFF
Abnormal Flashing ON
Abnormal Acknowledge ON OFF
Normal Slow Flash PULSING
Reset OFF OFF
Table 5
Sequence features
1. System test simulates an abnormal plant state on all alarms
2. Alarms should be set to lock-in
3. Only available in first-up modes F1, F2

20
Automatic Reset First-up ISA-F1A Sequence
PROCESS PUSHBUTTON VISUAL AUDIBLE
Normal OFF OFF
1st Alarm Abnormal Flashing ON
Subsequent Abnormal ON
Acknowledge
1st Alarm Abnormal ON OFF
Subsequent Abnormal ON OFF
Normal OFF OFF
Table 6
Sequence features
1. System test simulates an abnormal plant state on all alarms
2. Subsequent alarms do not lock in
3. Once acknowledged the first up alarm is reset.
Manual Reset First-up ISA-F2M-1 Sequence
PROCESS PUSHBUTTON VISUAL AUDIBLE
Normal OFF OFF
1st Alarm Abnormal Flashing ON
Subsequent Abnormal ON ON
Acknowledge
1st Alarm Abnormal ON OFF
Subsequent Abnormal ON OFF
Normal Reset OFF OFF
Table 7
Sequence features
1. System test simulates an abnormal plant state on all alarms
2. Subsequent alarms do not lock in alarms must be reset after inputs return to normal