Operating Instructions
MODEL ST-955 OtAP Modem for
ST-050 / ST-051 / ST-052
Manual # 600-1001
March 3, 1999
GENERAL
The ST-95x is an Over the Air Programming Modem for use with, ST-
051, and ST-052 voice encryption devices. The ST-95x connects to a
PC running Selectone Product Manager via a Female DB9 (RS-232)
serial connection. The ST-95x also connects to the host radio or
service monitor via a Male DB9 connector. All operation is under the
control of Product Manager
Selectone “Product Manager” software, is a Windows based RS-232 or
Over the Air Programming (OtAP) package. Selectone supports this
product with application assistance Via phone at (800) 227-0376, (510)
781-0376, FAX at (510) 781-5454, E-Mail at
[email protected], or on the World Wide Web at
www.selectone.com
SPECIFICATIONS
Specification
Detail
Operating Voltage:
5.2 Vdc to 16.3 Vdc
Operating Current:
Standby
<10 mAdc
Tx
<60 mAdc
Usable Audio Level Rx and Tx:
25 mV p-p to 2.5 V p-p
Temp: Range:
0
0
C to 70
0
C
RS-232 Interface:
Female DB9 with 6 foot PC
connection cable & adapter
Host Tranceiver Interface:
Male DB9 with connecting Female
DB9 + 24” application cable.
Size:
1.25” W X 3.50” L X 0.50” H
(31.7mm X 88.9mm X 12.7mm)
OPERATION
Operation is completely under control of the Selectone Product
Manager Software. Consult the on line help menu for operational
details the probability of lost speech from an operator that speeks
immediately after PTT activation. The encryption device begins to
digitally record mic. audio immediately following user activation of the
PTT. The recorded audio is then ciphered and played back for the
transmission at the appropriate time to accommodate systems delays.
The encryption device has voice storage capacity to accommodate up
to 1.2 seconds of system delay. The actual time required for system
delay is then made up at the end of the transmission by automatically
holding the transmitter keyed until the complete voice message is sent.
CONNECTIONS
Selectone supports this product with application assistance on our
TOLL FREE at (800) 227-0376 or request via E-Mail at
[email protected]. Completed applation notes are also
posted on our web page at
www.selectone.com
. The ST-95x is
supplied with a 24” appliacation cable for customizing connection to
the Host Radio or Service Monitor.
[P1-1] POSITIVE (+) SUPPLY
This wire should be connected to a positive DC voltage source in the
range of +5.2Vdc to +16.3Vdc.
[P1-5] NEGATIVE (-) SUPPLY
This wire should be connected to the negative lead of the powersupply
GND.
[P2-3] RS-232A INPUT
TD output pin of the PC RS-232 port (DB9 pin #3)(DB25 pin #3).
[P2-2 ] RS-232A OUTPUT
RD pin of the PC RS-232 port (DB9 pin #2)(DB25 pin #2).
[P1-7] TRANSMIT AUDIO OUTPUT
Transmit microphone audio signal to the host radio or service monitor.
The optimum location for connection is directly to the microphone
input.
[P1-8] RECEIVE AUDIO INPUT
The optimum location for connection is directly off the receiver detector
circuit BEFORE any audio processing circuits (de-emphasis). However
operation of any Rx audio point will generally be usable.
If not previously done for the host radio or service monitor, measure
the Tx and Rx level at the respective connection point. Inject the output
of an audio signal generator at 1KHz into The Tx audio circuit.
Measure and record the peak to peak level required to modulate the
transmitter at ½ system deviation with a 1KHz tone. Also measure the
level available for Rx while receiving a 1KHz tone at ½ system
deviation. These measurements X 2 should be used to determine the
proper setting required on the Audio TAB, of the Selectone Product
Manager.
[P1-9] PTT OUTPUT
The PTT OUTPUT manages the transmit signal to the host radio as
required OtAP Modem operation. Connect to the Radio PTT circuit
PTT operation is configured from the PTT operation block on the
Operation Tab in the Selectone Product Manager.
PTT Input
•
Active low:
Required programming state.
PTT Output
•
Active low:
Required programming state.
PROGRAMMING & ADJUSTMENTS
All adjustments, level setting and customization is accomplished with
Selectone Product Manager a PC Windows
based program via the
RS-232 port of a PC. During installation of Secure Speech Modules
connected to the Selectone Program Manager via RS-232 MUST be
made at least once to facilitate serial number loging to the database.
After the original setup, any of the available models, connected to a
host PC can be programmed or used as the RF modem to reprogram
any number of additional units via
O
ver
t
he
A
ir
P
rogramming (OtAP).
The PC Windows based program is fully documented with an on line
manual, accessed through the help menu. The online manual provides
advantages in that corrections and upgrades can be immediately
accessed via the Selectone Web page on the Internet.
