ZETRON Model 25 User manual

Model 25 Programmable
Encoder
Product Manual
025-9567E

Statements
025-9567E iii
© Zetron, Inc. All rights reserved. This publication is protected by copyright; information in this document is subject to
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Software License
The Zetron software described in this manual is subject to the terms and conditions of Zetron’s Software License
Agreement, a copy of which is contained on the product distribution media or otherwise provided or presented to buyer.
Installation and/or use of the Zetron software constitutes acceptance of Zetron’s Software License Agreement.
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buyer with such materials, such materials are provided solely for buyer’s convenience and shall not be binding on Zetron
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AS ZETRON'S SOLE AND EXCLUSIVE LIABILITY AND BUYER’S SOLE AND EXCLUSIVE REMEDY, Zetron
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AND THE THIRD PARTY MANUFACTURER'S WARRANTIES, IF ANY, ARE IN LIEU OF ANY AND ALL OTHER
WARRANTIES EXPRESSED, IMPLIED OR ARISING UNDER LAW, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY, NON-INFRINGEMENT AND FITNESS FOR A PARTICULAR
PURPOSE.
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Zetron makes no representation with respect to the contents of this document and/or the contents, performance, and function
of any accompanying software. Further, Zetron reserves the right to revise this document or the accompanying software and
to make changes in it from time to time without obligation to notify any person or organization of such revisions or changes.
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ANY INCIDENTAL, SPECIAL, CONSEQUENTIAL OR INDIRECT LOSS OR DAMAGE ARISING OUT OF OR
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PRICE PAID TO ZETRON FOR THE PRODUCTS.

Statements
iv 025-9567E
Regulatory Compliance
FCC Class A User Information
This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the
FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is
operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not
installed and used in accordance with the instruction manual, may cause harmful interference to radio communications.
Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be
required to correct the interference at his own expense.
Regulatory Compliance Markings
Product Certification Markings:
•FCC Part 15 (USA)
Change List for Rev D, 22 Oct 2012
Digital & Analog Encoder boards have been combined into a single Encoder board
Change List for Rev D.1, 27 Jul 2013
On page 146 Appendix D, include dimensions necessary for a user to create key labels on any graphics
program.

025-9567E v
Table of Contents
INTRODUCTION
OVERVIEW ........................................................................................................1
FRONT PANEL DESCRIPTION........................................................................1
Display .....................................................................................................2
Keypad .....................................................................................................3
Extended Keys .........................................................................................3
Instant Call Buttons..................................................................................4
SPECIFICATIONS
GENERAL...........................................................................................................5
ELECTRICAL .....................................................................................................6
SPECIAL FEATURES ........................................................................................7
OPERATION
OVERVIEW ........................................................................................................9
POWER ON.........................................................................................................9
USING THE KEYPAD .......................................................................................10
The Keyboard Stack.................................................................................11
Clearing an Entry .....................................................................................11
Sending a Call..........................................................................................11
Sending Live Calls...................................................................................12
Generating Alerts .....................................................................................12
Displaying the Time.................................................................................13
Accessing the Call Stack..........................................................................13
MAKING INSTANT CALLS .............................................................................13
Instant Call Key Numbering ....................................................................14
REMOTE CONTROL OPERATION..................................................................16
Call Logging ............................................................................................17
SETTING THE CLOCK......................................................................................19
CAUSES FOR ERROR BEEPS ..........................................................................20
THE CALLING SEQUENCE .............................................................................22
The Control Relays ..................................................................................22
Channel Busy Monitoring........................................................................22
Keying Method ........................................................................................23
Calling Sequence Summary.....................................................................24
RELAY TIMING DIAGRAM.............................................................................28
ENCODER INSTALLATION
OVERVIEW ........................................................................................................29
INSTALLATION PRECAUTIONS....................................................................29
RFI Caution..............................................................................................29
Proper Grounding of the Model 25..........................................................29

Contents
vi 025-9567E
Connecting the Power Supply to the Model 25 .......................................31
INSTALLATION PROCEDURE........................................................................31
Initial Conditions .....................................................................................31
Procedure .................................................................................................31
INITIAL TESTING .............................................................................................31
Deviation..................................................................................................32
Verification Mode....................................................................................32
Serial Port Control ...................................................................................33
DISASSEMBLY AND CIRCUIT LOCATION..................................................33
Keypad Enable/Disable............................................................................34
Display Scroll Enable/Disable .................................................................35
Channel Busy Impedance ........................................................................35
Audio Level Adjustment Range...............................................................35
Computer Port Connector Position ..........................................................36
Instant Call Clear Key Function ..............................................................36
Instant Call Left Column Function ..........................................................37
JUMPER AND SWITCH SETTINGS ................................................................37
Programming Enable/Disable Switch......................................................38
REAR PANEL CONNECTIONS........................................................................39
Transmitter and Console Control.............................................................40
Channel Busy Monitor.............................................................................42
Audio Output/Muting...............................................................................43
Tone Monitor ...........................................................................................43
Auxiliary Panels.......................................................................................44
Power .......................................................................................................44
COMPUTER PORT ............................................................................................45
PANEL LABELS.................................................................................................47
CLOCK OPTION ................................................................................................47
SOFTWARE UPDATES.....................................................................................48
Changing Options/Upgrading Current Software .....................................48
AUXILIARY PANEL INSTALLATION
OVERVIEW ........................................................................................................51
OPTION SELECTION ........................................................................................51
CONNECTING TO THE ENCODER.................................................................51
CONNECTING POWER.....................................................................................52
PANEL LABELS.................................................................................................53
TROUBLESHOOTING
POWER-ON SELF-TEST ...................................................................................55
CONTINUOUS SELF-TEST ..............................................................................57
INSTANT CALL KEY TEST .............................................................................59
ENCODER FAULT IDENTIFICATION............................................................59
INSTANT CALL FAULT IDENTIFICATION ..................................................62

Contents
025-9567E vii
PROGRAMMING ENCODER FROM FRONT PANEL
OVERVIEW ........................................................................................................65
How Programming is Organized .............................................................65
The Question Loop ..................................................................................66
THE IDLE STATE ..............................................................................................66
ENTERING A PROGRAMMING SELECTION ...............................................67
PROGRAMMING SECTION 1 - CLEARING AND INITIALIZING ..............67
PROGRAMMING SECTION 2 - TONE FORMAT SELECTION....................69
Question “bo”...........................................................................................69
Question “b” - Leading Digit Assignment...............................................69
Question “F” - Format Assignment .........................................................71
Two-tone..................................................................................................71
Motorola (2+2) Quick Call 1 ...................................................................75
5/6-Tone Sequential (Motorola) ..............................................................76
DTMF ......................................................................................................78
2805/1500 Hertz Rotary Dial...................................................................79
Alert Tone Format....................................................................................81
Digitone....................................................................................................83
Golay Sequential......................................................................................85
PROGRAMMING SECTION 3 - CUSTOM CALL SETUP..............................86
Single Tone Calls.....................................................................................86
Programming a Custom Call....................................................................87
PROGRAMMING SECTION 4 - INSTANT CALL BUTTON SETUP............89
PROGRAMMING SECTION 5 - GENERAL AND SEND BUTTON SETUP.92
General Operation Branch .......................................................................92
SEND Button Branch...............................................................................94
PROGRAMMING SECTION 6 - REMOTE CONTROL SETUP .....................96
PROGRAMMING ENCODER FROM SERIAL PORT
OVERVIEW ........................................................................................................99
CONNECTING TO THE SERIAL PORT ..........................................................99
MODEL 25 CONFIGURATION PROGRAM....................................................101
The Program Disk ....................................................................................101
Program Features .....................................................................................102
“Installing” and Running the Program.....................................................102
Manually Setting the COM: Port and Baud Rate.....................................102
CONFIGURATION PROGRAM OPERATION ................................................103
Serial Programming Command List ........................................................104
Creating a Configuration Printout............................................................107
ENTERING PROGRAMMING FROM A PC....................................................108
CLEARING AND INITIALIZING A SECTION ...............................................109
PAGING FORMAT SELECTION......................................................................109
CUSTOM CALL SETUP ....................................................................................111
INSTANT CALL BUTTON SETUP...................................................................112
GENERAL AND SEND BUTTON SETUP .......................................................114
General Setup...........................................................................................114

Contents
viii 025-9567E
SEND Button Setup .................................................................................116
REMOTE CONTROL SETUP............................................................................117
APPENDICES
APPENDIX A - PAGING FORMAT SPECIFICATIONS .................................120
Motorola and GE Tone Group Frequencies.............................................120
Motorola and GE Code Plans ..................................................................121
General Encoding Plans...........................................................................122
Model 25 Plan Numbers for Two-Tone 1000-Call Code Plans...............122
Reach Encoding Plan ...............................................................................123
Zetron Tone Groups for Reach Encoding................................................123
Reach Code Plan......................................................................................124
Five/Six-Tone Frequencies and Timings.................................................124
DTMF Tone Pair Frequencies and Timings ............................................125
Quick Call One (2+2) Frequencies and Timings .....................................125
Digitone Format .......................................................................................126
Golay Sequential Format .........................................................................126
APPENDIX B - UPGRADING FROM OLDER FIRMWARE REVISIONS ....127
APPENDIX C - INTERFACING MODEL 25 TO CAD SYSTEMS .................129
Computer-to-Encoder Interface ...............................................................129
Command Protocol ..................................................................................131
Computer Port Electrical Specifications..................................................133
Computer Port Physical Specifications....................................................133
Computer Port Communications Protocol Specifications .......................133
ASCII Control Character Usage ..............................................................134
Suggested Remote Control Parameter Programming ..............................134
INSTALLATION OF KEY SWITCH LABELS.................................................135
To replace the labels: ...............................................................................135
To replace with pre-printed key top:........................................................135
INDEX

025-9567E 1
INTRODUCTION
OVERVIEW
The Zetron Model 25 Programmable Encoder is a console or rack mounted selective
signaling encoder, specifically designed for use in public service and public utility dispatch
centers where operators need the ability to send calls quickly and efficiently.
The Model 25 provides several innovative features. One of these features is the ability to
send multiple calls over automatically selected channels by the press of a single Instant Call
pushbutton. Multiple Instant Calls may be queued for transmission to dispatch groups of
personnel quickly. Each Instant Call pushbutton shows its call progress via integral LEDs.
Since January of 2005, all Model 25 Encoders have shipped with paging formats and the
Instant Call option enabled. Model 25 Encoder purchased prior to the beginning of 2005 may
require an upgrade kit in order to enable all options. For encoders equipped with a keypad,
display, and only 29 Instant Call buttons, programming may be accomplished from the
keypad or from a PC connected to the computer port. For units equipped with 59 Instant Call
buttons, but no keypad or display, programming can be done only from a PC connected to the
computer port
Another feature is the RS-232 serial computer port. The port has several applications. One
application is the connection of a logging printer to log all activity of the encoder. With the
optional Real Time Clock, the time is also printed. Another application is the connection of a
PC to control the encoder remotely. Almost anything that can be done from the keypad may
also be accomplished via remote control.
As with all Zetron encoders, the advanced and reliable microprocessor design allows
upgrading of the Model 25 to virtually all signaling formats used in the communications
industry.
FRONT PANEL DESCRIPTION
The Model 25 Programmable Encoder may be ordered in one of two configurations. One of
these configurations (901-9019) is equipped with a keypad and display, allowing for manual
and backup operation. The keypad-equipped configuration also contains 29 Instant Call keys.
The other configuration (901-9022) contains 59 Instant Call keys but no keypad or display.
The front panel of the encoder without keypad looks identical to that of the Auxiliary Instant
Call panel (901-9020).
In the following discussions on operation, references to “status display”, “encoder display”,
“display”, “keyboard”, or “keypad” only pertain to the encoder configuration that is equipped
with these items (901-9019). In addition, references to “time” or “time clock” only pertain to
encoders equipped with that option.

Introduction
2 025-9567E
There are two basic modes of operation for the Model 25 encoder; remote control and instant
call modes. In remote control mode, input is accepted in ASCII from the RS-232 compatible
Computer Port, but the Instant Call panels are disabled. In instant call mode the Instant Call
panels are enabled but remote control is inhibited. Selection of the mode depends on the level
present on the “remote control” signal of the Computer Port connector. In either of the
modes, the keypad may either be enabled or disabled depending on the position of the keypad
jumper inside the enclosure. At all times, the status of the encoder is being displayed on the
front panel and if call logging is enabled outputted in ASCII via the Computer Port for
possible printing.
Figure 1. Model 25 Front Panel Controls
Callout # Item Description
1 Display Window (4 digits)
2 Keypad
3 Extended Keys
4 Send Buttons
5 Serial Port
6 Instant Call Buttons
Display
The Model 25 is supplied with a 4-digit, 7-segment, LED display. It is capable of displaying
alphanumeric characters. Figure 2 shows a few examples of the various characters and
prompts that can be displayed.

Introduction
025-9567E 3
2
FD
B
Figure 2. Sample Character Displays
Keypad
The keypad located on the front panel of the encoder is useful for:
Programming or altering the operation of your Model 25.
Manually entering any pager code available in the encoder. This feature is useful for
entering seldom used codes that are not assigned to an Instant Call button.
The keypad consist of keys for the digits 0 through 9, the letters A through D, as well as the
characters # and *.
1 2 3 A
4 5 6 B
7 8 9 C

0#D
Extended Keys
The Model 25 has four extended keys: RESET, CLEAR ENTRY, ENTER, and ALERT.
The extended keys provide a manual form of pager code entry. The ENTER and CLEAR
ENTRY keys are provided for “Keypad Stack” operation, and the ALERT key provides a way
to manually transmit an alert tone independent of any page. There is more information on the
“Keypad Stack” function later in this section.
RESET
The RESET key resets the Model 25 from any operating condition, and returns it to the “Idle
State”.

Introduction
4 025-9567E
CLEAR ENTRY
If a mistake is made while entering pager codes into the keypad stack, depression of the
CLEAR ENTRY key will erase the last entry, and allow the corrected code to be entered.
ENTER
This key is used to “enter” pager codes into the keypad stack. First enter the pager code into
the Model 25 from the keypad, then press ENTER, the code will be inserted into the keypad
stack.
ALERT
Many times, it is desirable to send an “Alert Tone” after a page. Although it is possible to
accomplish this by programming an Instant Call button, it is also possible to send manually
one of the four alert tones available in the Model 25 by:
1. Entering a single digit from the keypad
0 = Single Tone Alert
1 = Slow Siren
2 = Fast Siren
3 = HI/LO Siren
2. Press and hold the ALERT key for the duration of the desired alert.
Instant Call Buttons
The Model 25 contains 29 Instant Call buttons for “one-button” paging. Each of the Instant
Call Buttons may contain a single call or a group of calls from any of the formats available in
the encoder. This allows multiple units or individuals to be paged, and the correct channels to
be automatically selected by the press of a single button.
As many as 16 Instant Call buttons may be pressed at one time, the Model 25 will send the
pages of each button in the order in which they were pressed.
Each Instant Call button may be programmed to:
Send a single page or group of pages containing any format assigned in the encoder.
Automatic Channel Select of the proper channels for transmission.
Send an “alert” tone to audibly alert personnel as to the urgency of a call.

025-9567E 5
SPECIFICATIONS
GENERAL
Signaling Formats Motorola, GE, or Reach two-tone
Quickcall 1 “two plus two”
Five/six-tone sequential
Plectron and custom calls
2805Hz rotary dial
DTMF
Digitone
Golay Sequential
Consult factory for additional formats
Call Capacity 13 blocks of mixed formats, each block capacity is:
Two-tone Full code plan capacity ( 1000 calls )
Quickcall 1 Full format capacity
Five tone Full format capacity
Plectron/custom 196 calls total in encoder
2805/DTMF Full format capacity ( 3 to 8 digits )
Digitone Full format capacity
Golay Sequential Full format capacity, manual
message entry
Operating Temperature 0 to +65 ° Celsius
Size and Weight Encoder: 5.25" High, 19" Wide, 4.75" Deep, 5.5 lb.
Aux. Panel: 5.25" High, 19" Wide, 2.25" Deep, 3.5 lb.

Specifications
6 025-9567E
ELECTRICAL
Frequency Range 250 to 3276 Hz
Frequency Accuracy +/- 0.1%
Audio Output Drive Balanced, 600 ohm impedance
Audio Amplitude
Paging Output
(Tone Output 1)
Adjustable, -60dBm to -10dBm
( 0 - 0.75 V p-p, into 600 ohms)
( may be field altered to +7dBm maximum)
Audio Amplitude
Speaker Output
(Tone Output 2)
Adjustable, 3.6 V p-p max. (.2w into 8 ohms)
Tone Distortion 3 % nominal from pure sine wave
Pre/de-emphasis Factory set to +/- 1 dB over range, ( may be field altered to +/-
6 dB per octave)
TX Controls Audio switch: one DPDT relay
P-T-T: one DPDT relay
Channel select: 8 contacts, common when TX
( configuration may be field altered )
All relays rated at 1A at 26 VAC
TX Monitors 4 channel busy monitors each with high or low impedance
selection. Inputs are common ground
Computer Port RS-232, 8 bits, no parity, 1 stop bit
Baud rate: logging, 4800 baud only; remote control, 150,
600, 4800 baud
Full duplex when in remote control
CTS “busy” input available
Power Supply Encoder: 11 to 14 VDC at 2.5A max, 1A standby
Auxiliary Panel: 11 to 14 VDC at 1.5A max

Specifications
025-9567E 7
SPECIAL FEATURES
Display Four 0.40", 7-segment readouts
Utilizes some alphanumeric operator messages
Low RFI non-multiplexed drive
Channel busy LEDs 4 indicators showing status of channels
Key switches 16-key “DTMF” keypad, other keys are provided for channel
selection, stack editing, and alerts
Instant Call keys 29 Instant Call key switches with integral LEDs used to show
status. One clear key to clear the status
Instant Call queue 16 Instant Call buttons are remembered in the sequence in
which they were pressed
Call stacks One immediate keyboard stack plus 206 Instant Call stacks
Alerts 5 separate Alert tones: fast siren, slow siren, beeps, high-low
warble, and tone ramp
Re-Page The last entry or keyboard stack is again executed if the next
key after a call is a SEND key
Programming Attributes for computer port, channels, formats, stacks and
optional custom calls may be programmed
Self-test A limited self-test is executed while the unit is idle, extensive
self-tests are executed at user discretion, and after power-up
Expandability Additional formats may be added to the unit in the field using a
re-programmable plug-in memory. Additional Auxiliary Instant
Call panels may be added at any time
Options 59 button, Auxiliary Instant Call panels
24 hour, Real-time-clock
Extra Instant Call labels
Extra Instant Call red key tops
Power supply ( 120 VAC to 12 VDC )
Spare parts kit

Specifications
8 025-9567E

025-9567E 9
OPERATION
OVERVIEW
This section covers normal operation of the Model 25 once it has been installed and
programmed.
POWER ON
When power is applied to the Model 25, it automatically begins an extensive self-test. While
the encoder is testing, the LEDs of the encoder and all attached Instant Call panels will be
illuminated. The illumination of each LED allows an operator to verify their operation.
If a fault is found during the self-test then the encoder will display an error number (“Errx”)
and begin beeping until it is reset. If an Instant Call panel finds a fault during the test, it will
illuminate some indicators, one of which will be the LED of the CLEAR key (lower right-
hand key). See “ENCODER FAULT IDENTIFICATION” (page 59) to interpret the error
indications. The topic “POWER-ON SELF-TEST” (page 55) also contains information on
using the self-test at times other than power-on.
After the power-on self-test has successfully completed, the display of the front panel will
clear, displaying a single dash on the left (“- ”). The cleared display indicates that the
encoder is in the idle state awaiting entry of encoding information. While in the idle state, the
encoder is executing a limited self-test. Faults found in the limited self-test are indicated the
same way as in the full self-test. The four channel busy indicators will always indicate the
busy status of the connected channel busy inputs unless the encoder is in a programming or
test mode.
After long power losses in encoders equipped with time clocks, the date may need to be set.
If the clock needs setting then the display will flash the word “dAtE” while beeping. The
operation of setting the clock may be skipped by pressing RESET. For instructions on setting
the clock, see the subsection “SETTING THE CLOCK” on page 19. In encoders equipped
with the clock, the hours and minutes of the current time will automatically be displayed 30
seconds after the encoder enters the idle state. In addition, if a logging printer is connected to
the Computer Port, the time and date will be printed every hour.
Note: Before proceeding with operation, the Model 25 must be programmed if this has
not yet been done. As shipped from our factory, the Model 25 is not programmed.
Programming must be performed only by qualified personnel knowledgeable in
the details of the particular communications system. Once programmed, the
Model 25 will retain its memory, even during power failures, until re-
programmed.

Operation
10 025-9567E
USING THE KEYPAD
Note: If desired, the keypad may be disabled by placing the keypad jumper inside the
enclosure to the “disabled” position (see “Keypad Enable/Disable” on page 34).
To enter encoding information, use the 16-key pad. As digits are accepted from the keypad,
they will appear in the display filling in at the left-hand display first. There are two displayed
characters that are somewhat cryptic in their appearance due to the seven segment displays.
The “#” character is displayed as three horizontal lines, “ ”. The “*” character is displayed
as a “degree” symbol, “ ° ”. As the display fills, new accepted digits will enter on the right-
hand display while the previous display scrolls to the left. Entries that are not acceptable will
cause an error beep and they will not appear in the display. If the encoder fails to receive
keypad input for more than 30 seconds, it will re-enter the idle state displaying either the
time or the single dash. When this happens, the previous keystrokes are lost.
The first digit entered is the block or leading digit which is used to steer the encoder to one of
up to 13 formats or the call stack. The possible format leading digits are “1” through “D”.
The leading digit for accessing call stacks is “0”. If the attempted leading digit is not
accepted it is because the block represented by the leading digit has not been assigned to an
encoding format. After initialization, the leading digits 1, 2, and 3 are accepted to allow use
of the alert feature.
After the leading digit, the remaining digits are information used by the chosen encoding
format. Digits that are not accepted by the format will cause a beep. A beep may also be
caused by attempting to enter more digits than are allowed by the chosen encoding format.
Table 1 shows the required input for each of the formats supported by the Model 25. Note
that the leading block digit “b” must be in the range 1-9, A, B, C, or D. The actual block digit
used to access the given format depends on the programming. The leading block digit “0” is
reserved for accessing the call stacks.
Table 1. Page Entry Requirements by Paging Format
FORMAT REQUIRED ENTRY NUMBER RESTRICTIONS
CALL STACK 0nnn nnn= 000-358
1000 CALL TWO TONE bnnn n= 0-9
CUSTOM CALL bnnn nnn= 000-195
QUICK CALL 1 (2+2) bnnnn n= 0-9, A or B
5 TONE SEQUENTIAL bnnnnn n= 0-9
6 TONE SEQUENTIAL bnnnnnn n= 0-9
STORED DTMF bn - bnnnnnnnn n= 0-9, A-D, # or *
LIVE DTMF b digits sent as entered
STORED ROTARY DIAL bn - bnnnnnnnn n= 0-9
LIVE ROTARY DIAL b digits sent as entered
AUTOMATIC ALERT bn n= 0-3

Operation
025-9567E 11
After the encoding information (call number) has been entered it may be accumulated into
the keyboard stack, sent immediately, or in the event of an entry error, erased.
The Keyboard Stack
The keyboard stack provides a means of accumulating several calls prior to sending any of
them. This is useful in making best use of the channel airtime or for sending the same call
sequence over more than one channel.
To place a key sequence (call number) into the keyboard stack press the ENTER key. If
pressing the ENTER key causes an error beep, then more information is needed by the chosen
encoding format, and more digits must first be entered. If the call number is accepted into the
stack then the display will show a blinking dash. The blinking dash indicates that the
keyboard stack contains an entry. Attempts to enter invalid key-sequences (such as live
format blocks or the instant call block) will result in an error beep and several blinks of the
display after which the number will be cleared. Over 100 total keystrokes (including pressing
ENTER) may be placed in the keyboard stack before it must be sent. If a double beep occurs
when the ENTER is pressed then the keyboard stack is full. When this happens the last call
number will not be placed into the stack, but the entire keyboard stack and this last un-
enterable call number may be sent by pressing a SEND key.
Clearing an Entry
The CLEAR ENTRY key can be used to erase a key sequence before or after it has been
entered into the keyboard stack. If digits are displayed while the CLEAR ENTRY key is
pressed then the last key sequence is erased and the display will clear (“- ”). If the display is
clear but the keyboard stack contains key sequences, then pressing CLEAR ENTRY will
cause the last key sequence to be displayed and removed from the stack. Pressing CLEAR
ENTRY once again will clear the display. This process may be repeated until the keyboard
stack is completely erased. If pressing CLEAR ENTRY caused a beep then the keyboard stack
is empty and there are no key sequences to clear. A convenient way to erase the entire
keyboard stack is to press RESET.
Sending a Call
Pressing a SEND key causes the last unstacked call code to be forced into the keyboard stack
(if acceptable) even if the double beep indicated it was full. All call numbers sent over the
manually chosen channel are taken from the keyboard stack in the order in which they were
entered (first call number entered is the first call sent). Prior to sending, the encoder may
monitor the channel busy signal for the selected channel. If a channel busy signal is used and
it indicates busy then, the encoder will inhibit transmission until either the channel becomes
clear or until the SEND key is again pressed. For up to 30 seconds, the encoder will beep and
flash the word “bUSY” after which the attempt to send will be abandoned. Once the
transmission begins, it may be canceled only by pressing the RESET key. After the send
sequence is complete, the display will rapidly blink the last four digits of the last call number
sent. These blinking digits in the display indicate that the keyboard stack may again be sent
on the same or different channel by pressing the SEND key for the desired channel. After 30

Operation
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seconds, the display will stop blinking and the ability to re-page the keyboard stack will be
lost. Even though the display is not cleared after a send, the encoder is still in the idle state
and new encoding information may be entered as described previously.
Sending Live Calls
The live formats (live DTMF or live ROTARY DIAL) allow the encoding tones to be sent as
each digit is pressed. To initiate a live call, first select the leading digit of a live format then
press a SEND key. Live format blocks may not be entered into the keyboard stack. After the
key-up sequence, the encoding may begin by manually pressing the desired keypad digits.
Transmission may be halted by pressing the CLEAR ENTRY key or by allowing the five-
second keystroke time-out to expire. Sending live formats from remote control is not
possible.
Generating Alerts
Four separate alert tones may be generated from the tone output of the encoder by using the
ALERT key. Table 2 shows the available alert tone selections.
Table 2. Alert Tone Selections
Action Taken Alert Tone Produced
Display clear and ALERT pressed 1206 Hz tone
1 pressed then ALERT pressed Slow siren
2 pressed then ALERT pressed Fast siren
3 pressed then ALERT pressed Hi/Lo warble
The alert tones will be sent as long as the ALERT key is held down. While the alert is being
sent the PTT and audio relays close but none of the eight control relays will close because the
alert function is meant to key the channels already selected on the console. After the alert, the
display will clear. Unacceptable alert key sequences will cause an error beep.
An automatic customized alert is available that may be placed in a stack along with other
calls. The automatic alert is actually a format that is already resident in the encoder but it
must be enabled via programming before it may be used. The automatic alert format will
generate the same alert tones as the ALERT key with two exceptions; the tone ramp alert is
only available from the alert tone format, and instead of the steady 1206 Hz tone, the alert
format will generate a series of beeps. The number of beeps, the frequency of the beeps, the
beep duration, and the inter-beep gap are all programmable parameters of the auto-alert
format. The auto-alert format is accessed by keying-in the block number of the format
followed by a single digit that specifies the type of alert. The alert then may either be sent by
pressing a SEND key, or stacked with other calls by pressing the ENTER key. The alert-type
digit must be one of the following: