


Optoelectronics, Inc.
Scout
Serial Interface Specification

Interface Version 1.1
March 22, 1995

INTRODUCTION

This document describes the serial interface of the Scout, a miniature 
hand-held frequency counter capable of measuring the frequency of VHF and UHF 
transmitters and other signal sources.  The Scout has special features which 
make it invaluable for radio surveillance work.  In particular, the Scout is 
capable of automatically capturing and storing up to 400 frequencies, along 
with the number of occurrences, or count, of each frequency.  This frequency 
data can then be downloaded to a personal computer for logging and analysis.  
In addition, the Scout can be connected to a scanning receiver, such as the 
Realistic PRO-2006 or PRO-2005 receiver equipped with an OptoScan456 board, 
to automatically tune the receiver to captured frequencies in real time.  
In this configuration, frequencies captured by the Scout can be monitored 
immediately.

This document was written to assist the programmer in developing software 
applications for the Scout.

Optoelectronics, Inc. assumes no responsibility for the accuracy of the 
information contained in this document.  Optoelectronics, Inc. is under no 
obligation to provide technical support on matters pertaining to this 
document, or to provide notification of changes or corrections to this 
document.  To inquire about possible revisions, or to order copies of this 
document, contact the factory.  A nominal fee may be charged to cover 
printing and shipping costs.


OPTOELECTRONICS, INC.
5821 N.E. 14th Avenue
Fort Lauderdale, FL  33334
Phone:  (305) 771-2050
FAX:  (305) 771-2052



ABOUT CI-V

The serial interface on the Scout conforms to the Icom CI-V interface 
standard.  The CI-V interface is an asynchronous, half-duplex, Transistor 
Transistor Logic (TTL) serial interface connected in a wire-OR (bussed) 
configuration.  Several different devices can be connected to the bus 
simultaneously, and each device has its own unique address.  Software 
developers are strongly encouraged to obtain a copy of the Icom Communication 
Interface - V Reference Manual from Icom, Inc. for detailed information on 
the CI-V interface protocol.  The communications parameters for the serial 
interface are listed in Table 1 below.

Table 1.  Communications Parameters.
DATA RATE     9600 bps
START BITS    1
DATA BITS     8
PARITY        NONE
STOP BITS     1

One important thing to note about the CI-V interface is that, as mentioned 
above, it is connected in a wire-OR configuration.  This means that the 
transmit data signal and the receive data signal are connected together.  
Therefore, when a command is transmitted by the computer, it is automatically 
echoed back as received data, followed by the response to the command, if any.  
For example, if an eleven-byte command is transmitted to a device on the bus, 
which returns a six-byte response, the computer will receive a total of 
seventeen bytes.  This configuration allows devices on the bus to monitor 
their own transmissions in order to detect interface collisions.  A collision 
occurs when two or more devices transmit simultaneously.  If a collision 
occurs, the command must be re-transmitted.

To connect the Scout to a computer, a subminiature phone jack is provided 
on the top panel.  An external interface converter box, such as the 
Optoelectronics model CX12 or Icom model CT-17, is required to connect the 
Scout to an RS-232C computer interface.  Its purpose is to convert the 
CI-V interface voltage levels to RS-232C levels compatible with most personal 
computers.



CI-V ADDRESS JUMPER SETTINGS

There are two jumpers located on the Scout circuit board which are used to 
select the CI-V interface address.  Four different addresses are available, 
making it possible for up to four Scout units to be connected to a CI-V 
interface bus.  In order to communicate with the Scout, the computer software 
must specify the address selected by the two jumpers.  The CI-V address jumper 
settings are listed in Table 2 below.  All addresses are specified in 
hexadecimal notation.  The factory default setting is 90.

Table 2.  CI-V Address Jumper Settings.
U2 PIN 6        OPEN     SHORT    OPEN       SHORT 
U2 PIN 7        OPEN     OPEN     SHORT      SHORT 
ADDRESS         90       91       92         93 


COMMAND REFERENCE

As mentioned earlier, the Scout conforms to the Icom CI-V interface standard.  
In this section, all CI-V command and response bytes are expressed in 
hexadecimal notation.

When NORMAL mode is selected, the Scout recognizes eight different commands.  
The commands, along with their corresponding responses, are summarized in 
Table 3 below.  The Scout only responds to commands when NORMAL mode is 
selected (CAPTURE and RECALL switches both in the OFF position).  In all other 
modes, the Scout automatically tunes a receiver connected to the CI-V 
interface, and, therefore, can accept no commands.

Following the table is a detailed description of each of the commands, 
including examples illustrating their use.  In the command descriptions, 
"ra" refers to the RECEIVE ADDRESS, and "ta" refers to the TRANSMIT ADDRESS.

The RECEIVE ADDRESS is the address of the Scout.  The two address jumpers are 
used to select any address in the range 90 through 93.  Each device on the 
CI-V bus must have its own unique address.  The Scout will not process any 
command in which the RECEIVE ADDRESS does not match the address selected by 
the address jumpers.  However, the Scout will process commands with a RECEIVE 
ADDRESS of 00, but all command responses will be suppressed.  A RECEIVE 
ADDRESS of 00 has special meaning.  It provides a means for a device on the 
CI-V bus to transmit a command to all other devices simultaneously.  However, 
since several simultaneous responses would cause a collision, the responses 
are suppressed.

The TRANSMIT ADDRESS is the address of the device which is transmitting the 
command to the Scout.  In most cases, this device is a personal computer 
executing application software, usually referred to as the CONTROLLER.  
The standard address for the CONTROLLER is E0, but any address can be used 
for the TRANSMIT ADDRESS.  However, the TRANSMIT ADDRESS must be in the range 
01 to EF.  Also, the Scout will not process any command in which the TRANSMIT 
ADDRESS matches its own address selected by the address jumpers.




Table 3.  Scout CI-V Interface Command Summary.
COMMAND       SUB-COMMAND             DESCRIPTION
03            -                       Read frequency.
15            02                      Read signal strength.
7F            09                      Read identification
7F            20                      Read gate setting.
7F            21                      Write gate setting.
7F            22                      Read frequency memory.
7F            23                      Read count memory.
7F            24                      Clear memory.



READ FREQUENCY

Command:
FE FE ra ta 03 FD

Example:
FE FE 90 E0 03 FD

Response:
FE FE ta ra 03 frequency FD

Examples:
162.550000 MHz
FE FE E0 90 03 00 00 55 62 01 FD

1045.725000 MHz
FE FE E0 90 03 00 50 72 45 10 FD

Error
FE FE E0 90 FA FD

Description:
This command instructs the unit to send the current counter frequency 
measurement result.  This command is only valid when NORMAL mode is selected.

The frequency data is in the form of five bytes, each consisting of two 
BCD digits.  The order of the ten BCD digits is as follows:  10 Hz digit, 
1 Hz digit, 1 kHz digit, 100 Hz digit, 100 kHz digit, 10 kHz digit, 
10 MHz digit, 1 MHz digit, 1 GHz digit, 100 MHz digit.  See the examples 
shown above.

If the command length is incorrect, the command is ignored, and the error 
response is returned.  If NORMAL mode is not selected, the command is ignored, 
and no response is returned.






READ SIGNAL STRENGTH

Command:
FE FE ra ta 15 02 FD

Example:
FE FE 90 E0 15 02 FD

Response:
FE FE ta ra 15 02 sd FD

Examples:
0 bargraph segments
FE FE E0 90 15 02 00 00 FD

5 bargraph segments
FE FE E0 90 15 02 00 05 FD

16 bargraph segments
FE FE E0 90 15 02 00 16 FD

Error
FE FE E0 90 FA FD

Description:
This command instructs the unit to send the current signal strength.  This 
command is only valid when NORMAL mode is selected.

The signal strength data is in the form of two bytes, each consisting of two 
BCD digits.  The signal strength is reported as the number of bargraph segments 
active.  The reported signal strength ranges from a minimum signal of 0 
bargraph segments active to a maximum signal of 16 bargraph segments active.  
See the examples shown above.

If the command length is incorrect, the command is ignored, and the error 
response is returned.  If NORMAL mode is not selected, the command is ignored, 
and no response is returned.





READ IDENTIFICATION

Command:
FE FE ra ta 7F 09 FD

Example:
FE FE 90 E0 7F 09 FD

Response:
FE FE ta ra 7F 09 id  sv iv FD

Example:
Scout, software version 2.0, interface version 1.1
FE FE E0 90 7F 09 53 43 54 20 11 FD

Error
FE FE E0 90 FA FD

Description:
This command instructs the unit to send the identification information.  
This command is only valid when NORMAL mode is selected.

The identification data is in the form of five bytes, each consisting of two 
BCD digits.  The first six BCD digits uniquely identify the device.  The next 
two BCD digits indicate the current software version.  The last two BCD 
digits indicate the current interface version.

If the command length is incorrect, the command is ignored, and the error 
response is returned.  If NORMAL mode is not selected, the command is ignored, 
and no response is returned.




READ GATE SETTING

Command:
FE FE ra ta 7F 20 FD

Example:
FE FE 90 E0 7F 20 FD

Response:
FE FE ta ra 7F 20 gs FD

gs is a BCD value representing the selected gate setting.  BCD 
values are encoded as follows:

	00:     10 kHz resolution gate time
	01:     1 kHz resolution gate time
	02:     100 Hz resolution gate time
	03:     10 Hz resolution gate time

Examples:
10 kHz resolution
FE FE E0 90 7F 20 00 FD

100 Hz resolution
FE FE E0 90 7F 20 02 FD

Error
FE FE E0 90 FA FD

Description:
This command instructs the unit to send the current gate setting.  This 
command is only valid when NORMAL mode is selected.

The gate setting specifies the counter gate time, and, hence, the resolution 
of the frequency counter.  The gate setting data is in the form of one byte, 
consisting of two BCD digits.  See the examples shown above.

If the command length is incorrect, the command is ignored, and the error 
response is returned.  If NORMAL mode is not selected, the command is ignored, 
and no response is returned.




WRITE GATE SETTING

Command:
FE FE ra ta 7F 21 gs FD

gs is a BCD value representing the selected gate setting.  BCD
values are encoded as follows:

	00:     10  kHz resolution gate time
	01:     1   kHz resolution gate time
	02:     100 Hz resolution gate time
	03:     10  Hz resolution gate time

Examples:
1 kHz resolution
FE FE 90 E0 7F 21 01 FD

10 Hz resolution
FE FE 90 E0 7F 21 03 FD

Response:
FE FE ta ra FB or FA FD

Examples:
OK
FE FE E0 90 FB FD

Error
FE FE E0 90 FA FD

Description:
This command selects the gate setting.  This command is only valid when 
NORMAL mode is selected.

The gate setting specifies the counter gate time, and, hence, the resolution 
of the frequency counter.  The gate setting data is in the form of one byte, 
consisting of two BCD digits.  See the examples shown above.

If the command length is incorrect, the command is ignored, and the error 
response is returned.  If NORMAL mode is not selected, the command is ignored, 
and no response is returned.




READ FREQUENCY MEMORY

Command:
FE FE ra ta 7F 22 memory FD

Examples:
Memory location 0
FE FE 90 E0 7F 22 00 00 FD

Memory location 19
FE FE 90 E0 7F 22 00 19 FD

Memory location 247
FE FE 90 E0 7F 22 02 47 FD

Memory location 399
FE FE 90 E0 7F 22 03 99 FD

Response:
FE FE ta ra 7F 22 frequency FD

Examples:
162.550000 MHz
FE FE E0 90 7F 22 00 00 55 62 01 FD
				
1045.725000 MHz
FE FE E0 90 7F 22 00 50 72 45 10 FD

Error
FE FE E0 90 FA FD

Description:
This command instructs the unit to send the frequency stored in the specified 
memory location.  This command is only valid when NORMAL mode is selected.

The specified memory location data is in the form of two bytes, each 
consisting of two BCD digits.  The specified memory location must be in the 
range 0 to 399.  The frequency data is in the form of five bytes, each 
consisting of two BCD digits.  The order of the ten BCD digits is as follows:  
10 Hz digit, 1 Hz digit, 1 kHz digit, 100 Hz digit, 100 kHz digit, 
10 kHz digit, 10 MHz digit, 1 MHz digit, 1 GHz digit, 100 MHz digit.  
See the examples shown above.

If the command length is incorrect, or if the specified memory location is 
not in the range 0 to 399, the command is ignored, and the error response is 
returned.  If NORMAL mode is not selected, the command is ignored, and no 
response is returned.



READ COUNT MEMORY

Command:
FE FE ra ta 7F 23 memory FD

Examples:
Memory location 0
FE FE 90 E0 7F 23 00 00 FD

Memory location 19
FE FE 90 E0 7F 23 00 19 FD

Memory location 247
FE FE 90 E0 7F 23 02 47 FD

Memory location 399
FE FE 90 E0 7F 23 03 99 FD

Response:
FE FE ta ra 7F 23 count FD

Examples:
37 occurrences
FE FE E0 90 7F 23 00 37 FD

214 occurrences
FE FE E0 90 7F 23 02 14 FD

Error
FE FE E0 90 FA FD

Description:
This command instructs the unit to send the number of occurrences of the 
frequency stored in the specified memory location.  This command is only 
valid when NORMAL mode is selected.

The specified memory location data is in the form of two bytes, each 
consisting of two BCD digits.  The specified memory location must be in the 
range 0 to 399.  The count data is in the form of two bytes, each 
consisting of two BCD digits.  The count will be in the range 0 to 255.  
See the examples shown above.

If the command length is incorrect, or if the specified memory location is 
not in the range 0 to 399, the command is ignored, and the error response is 
returned.  If NORMAL mode is not selected, the command is ignored, and no 
response is returned.





CLEAR MEMORY

Command:
FE FE ra ta 7F 24 FD

Example:
FE FE 90 E0 7F 24 FD

Response:
FE FE ta ra FB or FA FD

Example:
OK
FE FE E0 90 FB FD

Error
FE FE E0 90 FA FD

Description:
This command clears all frequency and count memory locations.  This command 
is only valid when NORMAL mode is selected.

Once this command is executed, all frequency and count memory bytes are set 
to zero.  The Scout can then begin to capture 400 new frequencies.  This 
command has the same effect as turning the unit off and back on.

If the command length is incorrect, the command is ignored, and the error 
response is returned.  If NORMAL mode is not selected, the command is ignored, 
and no response is returned.







OPTOELECTRONICS, INC.
5821 N.E. 14th Avenue
Fort Lauderdale, FL  33334
Phone:  (305) 771-2050
FAX:  (305) 771-2052




