1. Computer to Radio Interfacing
May 14, 2012

2. A Very Simple Interface Procedure!
Radio with RS-232 Interface
Computer Running a
Terminal Program

3. The Rig we’ll use is the Ten-Tek Omni 6 Plus
Reasons are:
Large easy to see readouts
Straightforward RS-232 I/O
Easy to carry
The Terminal we’ll use is the N2FJP Logging Program
Reasons are:
We will use it at Kids Day and at Field Day
It is more or less intuitive to operate
It has only a limited range of capabilities.

4. The communication capability built into the Logging Program can:
Send a code to the transceiver asking it to return a code with it’s operating frequency, and the program will put that frequency on the working screen.
Send a code to the transceiver asking it to return a code with it’s operating mode (CW or PH), and then put the answer on the screen and into the log.
Send a code to the transceiver asking it to return a code with it’s operating band, and then put the answer on the screen and into the log.
Send various other codes to the transceiver ordering it to change one of it’s operating parameters (frequency, mode, filter bandwidth, etc.), and then expecting an answer from the transceiver which indicates the order has been performed (not performed).

5. In the case of the Ten-Tek the codes are Packets, having variable lengths depending on what is being asked for or what it is being commanded to do….
BUT
The Packets always have:
a Start Signal (like CQ),
a set of addresses (K2JV this is K2AL),
an action command (QSY),
a set of data codes (such as “ ”),
and an End Signal (over or out).
The Ten-Tek is a simple “Slave System” and does not originate Commands on it’s own, so…
The Computer (Master) must “Poll” the transceiver regularly in order to stay up to date on it’s activity.

6. The General Command Format
When the Computer calls the Transceiver
Start Code Calling Ten-Tek This is the Computer Do This… Use This… End of Message
Address - 04h
Address = E0h
There are about 20 Command and Response codes which the Ten-Tek will recognize. A few of them are listed below, the first three are the ones used by the logging program:

7. There are also a bunch of Data Codes which represent the operating conditions of the rig
Modes
Filters
And then there is the case when you need to send frequencies as decimal numbers
The computer will parse them out into 5 bytes encoded as BCD digits -- OY Vay!
And worse, the bytes are sent in reverse order, least significant numbers first. For example…
is sent as

8. Another Simple Command
A Simple Command Sent Repeatedly to the Transceiver
The spaces are put in by the computer which Parses the codes into 2 byte words:
FE FE 04 E0 03 FD FE FE E FD
Answer: I’m on MHz
Start - Ten-Tec de Computer
What Freq? EOM
Another Simple Command
FE FE 04 E0 04 FD FE FE E FD
What Mode are you in?
I’m in Mode 0 (LSB) and using Filter #2 (2,4 kHz)

9. N3FJP Main Screen with Frequency, Mode, and Data Displayed

10. N3FJP Rig Interface Setup Screen