Selectone ST-25B Manual de usuario

Manual # 600-1501 June 19, 1999

Rev. A - 99038

PRODUCT GROUP

OPERATING INSTRUCTIONS

Model ST-25B

Rolling Code Voice Encryption Module

OPERATION

Operation is almost transparent to the user. The user may select any one

of 4 previously programmed User Code Keys. The user then enables or

disables the transmit cipher mode. Once enabled all subsequent

transmissions will be ciphered using the selected User Code Key.

Ciphered reception is automatic; other units transmitting with the

selected code key will be automatically deciphered. Clear transmissions

will also be received automatically.

Each radio model provides different operational challenges. This is

generally due to availability of unassigned switches or blank panel

space capable of supporting accessory switches. To accommodate

these varying situations the ST-25B provides two modes of operation for

enabling and disabling transmit cipher operation, and making User

Code Key selections.

SWITCHED MODE

This is the default mode of operation, as shipped from the factory.

Clear/Ciphered switching is achieved by a dedicated switch

providing a single closure to (-) Supply. User Code Key selection is

also selected by a dedicated switch providing a binary input to the

two Code Select lines on the ST-25B.

DOUBLE CLICK MODE

This mode of operation is enabled during programming. Operation

with this mode minimizes accessory switch requirements on the

radio. The Clear/Ciphered line is connected to any switch (except

PTT) capable of providing momentary closures to or away from

ground. The switch retains its normal functions; however the user

can toggle between Clear/Ciphered by operating the switch two

times in rapid succession (Double Clicking). The ST-25B will then

provide a tone output to the radio speaker. A high frequency beep

or series of beeps indicate subsequent transmissions will be

ciphered. A low frequency tone for .5 Sec. indicates subsequent

transmissions will be in the Clear (NOT Ciphered).

User Code Keys are selected by operating the same switch four

times in rapid succession (Quad Clicking). Quad Clicking permits

switching between User Code Keys when in the transmit Cipher

Mode (Double Click selection). Each Quad Click transaction

advances the selected User Code Key one step around a loop of

possible selections (Primary, Alt #1, Alt #2, Alt #3, Primary ...).

Following a Quad Click sequence the ST-25B responds with

speaker beeps to indicate the selection position (Primary: 1 Beep,

First Alt: 2 Beeps, Second Alt: 3 Beeps, Third Alt: 4 beeps). When

returning to cipher mode from clear mode, the last used User Code

Key will be selected and indicated with speaker beeps. Following

power-up Cipher operation will select the Primary User Code Key.

Slow switching of this control permits operation in a normal manner

as assigned by the radio manufacturer. Typically this is connected

to the monitor switch, but other switches can be used (freq.

select).

In either mode a visual cipher indicator is available.

INITIAL SYNCHRONIZATION DELAY

All radio systems have an operating delay. This is the time between

PTT activation at a transmitter and speaker audio being available at

the receiving point. This time may vary considerably from system to

system or even from transmission to transmission. For reliable cipher

operation, the ST-25B must wait for this time period before signaling

the beginning of a ciphered transmission. System delays must be

evaluated and accommodated for with the INITIAL SYNCHRONIZA-

TION DELAY parameter.

GENERAL

The ST-25B is a frequency domain rolling code voice encryption device

used to protect the security of two way radio communication systems.

The cipher process uses a proprietary microprocessor controlled analog

scrambling algorithm. Each unit can be programmed with four User

Code Keys, with over 4 billion code keys to choose from. Special

factory set master code key groups are reserved to provide extra security

for special services. Each master code key group has over 268 million

possible code keys. To maintain security, code keys are never

transmitted. Audio processing filters provide high quality low distortion

recovered audio. The small size and low power requirements make it

ideal for portable, mobile, and base station use.

The ST-25C and ST-25B are code-compatible and may be used in the

same system. The only difference between the two units is that the

ST-25C provides a path for CTCSS tones while the ST-25B does not. The

ST-25B should be used when the unit is installed in the receive audio

path after the CTCSS decoder. The ST-25C must be used if the unit is

installed before the CTCSS decoder.

Field programming is accomplished using a PC serial connection, and

Product Manager Software. Product Manager is available on disk from

SmarTrunk at a nominal price, or it is available at no charge on the

Selectone web page www.selectone.com. Product Manager is supplied

as two separate programs for use with Microsoft Windows or DOS.

ST-25PM Windows & DOS based Product Manager

ST-954B RS-232 to Selectone connector adaptor.

Application information is available or can be developed for most radio

models. Documentation on ALL current products and many of our

application notes are available for instant access on our web site

www.selectone.com. If you would like application details for a specific

radio, please call us at (510)887-1950 or request assistance via E-Mail

at [email protected].

OPERATING SPECIFICATIONS

SPECIFICATION DETAIL

Encryption: ....................................... 32 bit algorithm

Operating Voltage: .......................... 5.2 Vdc to 16.3 Vdc

Operating Current: .......................... < 8mAdc

User Code Keys: .............................. Greater Than 4 billion

Cipher Algorithm: ............................. Real Time Frequency Domain

Synchronization: .............................. Initial and Maintenance

Usable Audio Level Rx and Tx: .......... 25 mV p-p to 2.0 V p-p

Input to Output Gain: ...................... < ± 1 dB

Frequency Response: ...................... 300 Hz to 2600 Hz

Temperature Range: ........................ -30° C to +60° C

Interface: ......................................... 18 flying leads terminated in a

13 pin low profile connector

Size: .................................................. 0.90 W x 1.50 L x 0.18 H

(22.8mm x 38.1mm x 4.6mm)

IMPORTANT

Note: Operation of radio equipment with encrypted speech capability

may be government regulated. The purchaser of this equipment is

responsible for compliance with applicable radio regulations regarding

operation of this equipment.

Note: Export of this product is under the jurisdiction of the U.S. Depart-

ment of Commerce, Office of Defense Trade Control. An Export

License is Required.

internal DC bias voltages in the transmit audio stages. If this is not

possible, a DC blocking capacitor should be placed in series with this

lead.

[11] RECEIVE AUDIO INPUT (BLUE)

[1] RECEIVE AUDIO OUTPUT (WHITE/BLUE): These two wires should be

connected in series with the receive audio path inside the radio. The

optimum location for connection is directly off the receiver detector

circuit BEFORE any audio processing circuits (de-emphasis). This

connection location will provide high quality audio recovery. Be sure

not to break the audio path between the detector and the squelch

circuit, or between the detector and the CTCSS decoder if one is used.

Also, be sure that the receive audio path is broken next to a DC

blocking capacitor, or in such a location as not to upset any internal

DC bias voltages in the receiver audio stages. If this is not possible, a

DC blocking capacitor should be placed in series with this lead.

Note: In some applications it is impossible to avoid breaking the path

between the detector and the input to the CTCSS decoder. For these

applications it is necessary to use the ST-25C, to permit CTCSS to pass

through the board without being eliminated or ciphered.

[6] PTT INPUT (YELLOW): The PTT Input detects a pull to ground on the PTT

line in the radio set to indicate a transmit condition. To install the PTT

Input line on the ST-25B, connect this wire to the PTT line in the radio set

at a convenient location.

Note: Operation of the ST-25B will be erratic if the PTT input is allowed to

float. If this point floats when the transmitter is not keyed, a pull-up

resistor to Positive (+) Supply must be added.

[10] PTT OUTPUT (BLACK/YELLOW): This lead is not used for this product.

[4] SPK BEEP/CIPHER LED/RS232 OUT (WHITE/ORANGE): Speaker Beep &

Double Click Mode: Speaker beep is vital to operation in this mode. This

lead is the beep output. It may usually be connected directly to the

high side of the speaker. In some applications direct speaker connec-

tion may not be usable. In these cases connect to the input of the

receiver audio amplifier through a series resistor. The value of the series

resistor will have to be determined experimentally.

[8] AMP ENABLE (BLACK/BROWN): Many portables power down the

receiver audio amplifier when squelched.

Double Click Mode: When beep tones are not present this lead is high

impedance. During beeping it is switched to ground through a series

10K resistor. If the receiver audio amplifier is turned off while the receiver

is squelched, this output may be used to enable the amplifier for

speaker beeping.

[2] CODE SELECT 1 INPUT/ RS232 INPUT (VIOLET)

[5] CODE SELECT 2 INPUT (BLACK/ORANGE): When not used as an

RS232 INPUT, these two inputs are used for selecting up to four unique

code keys on the ST-25B. These inputs have pullups to +5Vdc internal

to the uP, and may be left unconnected if only the Primary User Code

Key is to be used. The three Alternate User Code Keys are selected by

connecting these leads to a binary coded switch. The switch must

cause switching to ground (logic low) as indicated in Table 1 (Logic

High = Open, Logic Low = Grounded).

TABLE 1

CODE KEY CODE SELECT 1 CODE SELECT 2

Primary Open Open

Alt #1 Grounded Open

Alt #2 Open Grounded

Alt #3 Grounded Grounded

MOUNTING

Use of a double-sided adhesive pad or an insulating shrink tube

eliminates hardware requirements. When using the adhesive pad,

mount the ST-25B on a clean dry surface, oriented to allow easy routing

of the wiring to the radio and to allow future adjustments should they be

necessary. Press firmly after mounting to ensure good adhesive

contact. Do not touch the adhesive surface or attempt to re-position

after mounting.

ADJUSTMENTS

GAIN SETTINGS

As shipped from the factory, the ST-25B is fully functional for

many applications. However experience indicates the ST-25B

functions best when audio signals internal to the ST-25B are at or

near pre-determined levels. To optimize operation, receive and

transmit levels must be evaluated independently and the proper

gain setting resistors must be installed. Use the following proce-

dures to determine the input level for the receive and transmit

audio paths. The measured levels are for evaluation with TABLE 2.

Use TABLE 2 to select resistors values for optimum operation.

For many radio operators it is difficult to know reliably how long to

wait before speaking in ciphered mode. This can cause loss of the

beginning of a message. The ST-25B can be programmed to

accommodate this problem. For cipher transmissions the ST-25B will

provide all the necessary timing and beep the speaker as a GO

AHEAD and speak indication.

USER CODE KEYS

Of the more than 268 million available code keys, four may be

selected and easily accessed as User Code Keys for each unit.

These may be used to provide different levels of security within a

particular radio system (officers, sergeants, lieutenants, captains).

INSTALLATION

Installation should be done only by a qualified two-way radio techni-

cian. Installation consists of programming, then mounting the unit in the

radio set, and making the electrical connections.

Note: Installation of secure speech equipment is often time consuming

and costly due to the application requirements presented by the radio

equipment. We may be able to provide a substantial cost savings for

installation. Please contact the SmarTrunk Sales Department for details

on factory installation of secure speech equipment.

SmarTrunk supports this product with application assistance via phone

line and with APPNOTES (Application Notes). We encourage use of our

application service to determine hookup. Most radios do not provide an

interface connector for easy installation of voice encryption equipment

as is often provided for CTCSS applications. Radios that are not in our

application library will receive special consideration and may qualify for

sample installation of two units at the Selectone factory for no cost.

Installation requires a minimum of eight external connections. These

connections are Power, Ground, Transmit Audio Input and Output,

Receive Audio Input and Output, PTT Input, and the Clear/Ciphered

Input. The most critical connections are Transmit Audio Input and

Output, and Receive Audio Input and Output. Improper installation of

these connections can result in distorted audio, and the loss of either

high or low frequency voice components.

ELECTRICAL INTERFACE

The following paragraphs describe each of the external connections.

Numbers shown in brackets [#] refer to the connector pin number.

[3] POSITIVE (+) SUPPLY (RED): This wire should be connected directly to a

filtered source of continuous positive DC voltage in the range of

+5.2Vdc to +16.3Vdc. This connection should be made downstream

from the power switch and the power supply filter components in the

radio set. If a regulated source of DC voltage is available, it should be

used. Low level microphone audio is passed through the ST-25B and use

of a quiet and stable source of DC voltage inside the radio set will

reduce the possibility of picking up power supply noise that may affect

audio signals.

[9] NEGATIVE (-) SUPPLY (BLACK): This wire should be connected to a

location inside the radio that will supply a DC power ground return to the

ST-25B. To eliminate ground loops and power supply noise, the ground

return should be the same power supply ground used in the transmit and

receive audio stages.

[7] MONITOR/CLEAR/CIPHERED (BROWN): Double Click Mode: This wire is

used as an input line for the Double Click and Quad Click signal. It is

normally tied to the monitor switch of the radio, however any switch can

be used. The connection point in the radio must switch between logic

states, high (>4Vdc) and logic low (< 1Vdc). The ST-25B analyzes

transition between these levels and is not concerned with the resting

state. This lead is intended to operate in parallel with the existing radio

function without effecting radio operation.

Switched Mode: This wire is used to select the transmit in cipher mode

when pulled to logic low (< 1Vdc). This may be accomplished with an

ON/OFF SPST switch. When this lead is at logic high (> 4Vdc) the ST-25B

will operate in clear mode when transmitting.

[12] TRANSMIT AUDIO INPUT (GREEN)

[13] TRANSMIT AUDIO OUTPUT (WHITE/GREEN): These two wires should

be connected in series with the transmit microphone audio signal path

inside the radio set. The optimum location for connection is directly in

series with the microphone. If the microphone requires bias, then the

audio path MUST be broken downstream of the bias source. In order to

provide the best transmit audio quality, be sure that the transmit audio

signal path is broken BEFORE the pre-emphasis and transmit modulation

limiter circuit. Also, be sure that the transmit audio path is broken next

to a DC blocking capacitor, or in such a location as not to upset any

PROGRAMMING

The ST-25 Product Manager is required to configure this product to

accommodate the specific application requirement.

The Windows based Product Manager ST25.exe installs using normal

Windows installation procedures. This program defaults to use serial port

com2. To use com1 add /1 to the launch command (ST25.EXE /1)

The DOS based Product Manager is included on a separate disk. The

DOS Product Manage 025DOS.exe may be transferred to the working

directory (C:\Select.one), or run directly from the supplied disk.

Many popular Windows programs access serial communications and

lock access to COM ports by any other program, Windows or DOS.

Before running 025DOS.EXE, shut down the computer and reboot in

DOS mode. For DOS operation, press F8 immediately following the report

Starting Windows 95. Select Command Prompt Only.

Note: The security of your system depends on the secrecy of your code

keys. For maximum security, Selectone recommends changing your

code keys often.

ST-25B COMPONENT LOCATOR

The ST-25B uses multi-layer printed circuit boards. Field repair is not

recommended.

Measurements may be made with an oscilloscope or an AC level

meter. For convenience TABLE 2 presents input levels in mV peak

to peak and mVrms.

TABLE 2

Input Level Gain Resistor

mVpp mVrms TX R35 TX R28

From To From To RX R21 RX R4

10 65 4 23 1.1K 1.1K

65 125 23 45 2.2K 2.2K

125 250 45 89 4.7K 4.7K

250 500 89 179 11K 11K

500 1000 179 357 33K 33K

1000 2000 357 714 None None

Receive: Measure the level on the [11] RECEIVE AUDIO INPUT

(BLUE) lead while receiving a full quieting signal modulated at full

system deviation. Use this level to select R21 and R4 from TABLE 2.

Transmit: The RF generated by the transmitter often makes it

difficult to make accurate measurements for the microphone

circuit. Two methods of measurement are presented, the first does

not always produce accurate results. If method 1 does not appear

effective use method 2.

METHOD 1

Key the transmitter and while speaking loudly into the microphone,

measure the Peak to Peak level on the [12] TRANSMIT AUDIO INPUT

(GREEN) lead. Use this level to select R35 and R28 from TABLE 2.

METHOD 2

Disconnect the [12] TRANSMIT AUDIO INPUT (GREEN) from its

connection in the radio. Use an audio signal generator to inject a

1KHz tone into this lead. Key the transmitter and adjust the output

level from the signal generator to produce 2/3 system deviation as

measured on a service monitor. Un-key the transmitter and

measure the output level from the signal generator. Use this

reading multiplied times 4 to select R35 and R28 from TABLE 2.

NOTE: In some cases the output level from the signal generator

may be too low for accurate readings, or the level may be difficult

to adjust. In these cases build a resistive divider with the supplied

11K and 1.1K resistors from the resistor packs. Dont damage the

resistors they may be required as gain resistors. Connect the 11K to

the output of the signal generator, connect the 1.1K to (-) Supply

for the ST-25B, and connect the junction between the resistors to

[12] TRANSMIT AUDIO INPUT (GREEN). Key the transmitter and

adjust the output level from the signal generator to produce 2/3

system deviation as measured on a service monitor. The output

level from the signal generator divided by 10 produces 2/3 system

deviation. Use this reading times 2 to select R35 and R28 from

TABLE 2.

Dont forget to reconnect the [12] TRANSMIT AUDIO INPUT (GREEN)

lead in the radio.

SYNCHRONIZATION LEVEL

During cipher transmissions the ST-25B transmits synchronization

information approximately twice per second. This signal carries no

coding information but is necessary for proper operation. For

optimum performance the synchronization bursts should be

adjusted to produce 1/2 system deviation.

After installation is complete, switch to the cipher mode and key

the transmitter. Using a service monitor with an oscilloscope

display, adjust R24 for a peak reading of ± 1/2 system deviation.

Deviation readings made with a deviation meter may not

accurately measure the intermittent synchronization burst signal. If

proper adjustment is difficult or not possible, the transmit audio

gain may be set incorrectly. Repeat the gain setting procedure for

the transmitter using METHOD 2. If difficulties continue, contact

the Selectone Applications Department for assistance.

WARRANTY POLICY

All Selectone products are guaranteed to meet or exceed published

performance specifications and are warranted against defects in

material and workmanship for a period of two (2) years from date of

purchase. Third party equipment such as radios, power supplies,

antennas, etc., carry the factory warranty of their respective manufac-

turers.

All warranty repairs must be performed at the SmarTrunk factory in

Hayward, California, or other factory authorized repair depot. Any

unauthorized repair attempted by the customer, alteration or modifica-

tion of the equipment, damage by external sources, or removal or

alteration of the serial number label or date code, will void the warranty.

Specifically excluded from this warranty are batteries, fuses, lamps, and

damage caused by lightning, power surges, or mechanical abuse.

Equipment for repair may be returned to the factory without prior written

authorization; however, a note must be sent with the packing list briefly

describing the nature of the defect. Repairs must be shipped freight

prepaid and will be returned freight prepaid. Shipments should be

directed to:

SmarTrunk Systems, Inc.

Attn: Repair Department

23278 Bernhardt Street

Hayward CA 94545, U.S.A.

SmarTrunk Systems, Inc.

23278 Bernhardt Street  Hayward, CA 94545-1621 USA

Phone: +1-510-887-1950 - (- Fax: +1-510-887-4011

Email: [email protected]  Web Address: http://www.smartrunk.com

ST-25B SCHEMATIC

Note:

1. Board layout allows loading R21 and R35 as

surface-mount or through-hole components.

Manuales populares de Unidad de control de otras marcas

Festo

Festo Compact Performance CP-FB6-E Manual de lista de piezas

Elo TouchSystems

Elo TouchSystems DMS-SA19P-EXTME Manual de usuario

JS Automation

JS Automation MPC3034A Manual de usuario

JAUDT

JAUDT SW GII 6406 Series Guía rápida

Spektrum

Spektrum Air Module System Manual de usuario

BOC Edwards

BOC Edwards Q Series Manual de usuario

KHADAS

KHADAS BT Magic Manual de usuario

Etherma

Etherma eNEXHO-IL Manual de usuario

PMFoundations

PMFoundations Attenuverter Manual de usuario

GEA

GEA VARIVENT Manual de usuario

Walther Systemtechnik

Walther Systemtechnik VMS-05 Manual de usuario

Altronix

Altronix LINQ8PD Instrucciones de montaje

Eaton

Eaton Powerware Series Manual de usuario

WAGO

WAGO 750-407/040-000 Manual de usuario

Sony

Sony CCU-590 Manual de usuario

Graco

Graco 25D614 Manual de usuario

Task Force Tips

Task Force Tips YE-RF-900 Manual de programación

Shini

Shini SPV-U Series Manual de usuario