EncoderCAT - radio compatibility

PC based CAT systems hold the control codes for a wide range of radios.
EncoderCAT does not do this.

• It only needs to store the control sequences for eight parameters (controlled by the eight encoders)
• The control code formats are entered by the user, via USB using my PC based application xCAT.

Encoder actions occur when the operator clicks an encoder up or down.
Most encoder actions will be read - modify - write, eg, the RF power action is:

- Read power from rig.   Increment or decrement the value.  Write the modified RF power back to rig.

EncoderCAT has been developed using a new Yaesu FTdx101D transceiver and an  Icom IC7000.

Yaesu and Kenwood  continue to provide a DB9, 9 pin RS232 CAT interface on their radios.

I understand that Elekraft use RS232 via a RJ45 connector.

I read that the adapter cable used with a P3 panadapter can be used for PC connection.

These RS232 connected rigs all use CAT commands in the form of ASCII character sequences.
These are easy to understand and manage. For example, Yaesu RF power control uses  PC.

eg:  read power from rig is: PC;      answer from rig is:  PC085;  (85w)       set rig power is:  PC090; (90w) .

The corresponding user-entered configuration masks are:  

  read mask = PC;    answer mask = PChtu;   set mask = PChtu;   ( h = hundreds, t = tens, u = units)  

Icom transceivers' CAT interface is their CI-V system.
This is a single bidirectional wire with open drain drive and pullup resistors.
The supply voltage appears to be 3v3.  (from test meter on IC7000 CI-V line and also from circuit diagram)

The connection is a mono 3.5mm jack socket.

The EncoderCAT PCB has a 3.5mm jack socket for direct connection to a rig.
Icom's CI-V adapters are not needed.

( Icom's RS232 adapter is discontinued  The currently available adapter is USB )

There are a range of  RS232 to CI-V adapters  (Icom and also homebrew on the internet)
These connect RS232 Rx and Tx lines (through appropriate buffering)  to the single CI-V line.

This results in Tx data returning down the Rx line during transmission.
EncoderCAT uses an NXP PCA9600 bidirectional buffer device which avoids this feature by having the input-low threshold voltage lower than then output pulldown level.

Icom CI-V  coding is a little more complex than a simple ACSII system.

It uses CAT commands in the form of sequences of bytes specified in hexadecimal:

• Hexadecimal command codes, eg:  1A hex
• Decimal data values represented in Binary Coded Decimal format  (BCD)

Hexadecimal bytes in this document are represented with the prefix 0x. ( as used C and PHP languages)

eg: 0x2A  is hexadecimal 2A  = 2 x16 + 10 =  decimal 42.

BCD format represents  two decimal digits as a single hexadecimal byte.

   eg:  decimal 37  is  0x37 ... easy to read   (but on hex to dec conversion = 3 x16 +7 = 55 decimal)

EncoderCAT software does the decimal to BCD conversion for you.
This allows you to enter command 050014 as such in decimal
(EncoderCAT then transmits this as three bytes:  0x50  0x00   0x14 )

Icom's command system is complicated by what would appear to be historical / evolutionary features.

The range of formats includes:

• single hex command byte.
• hex command byte + hex sub-command.
• hex command byte + hex sub-command byte + bcd data byte.  (read only - but read/write in later rigs).
• hex command byte + two bcd data byes  ( read/write). The bcd bytes referred to as sub-command.
• hex command byte + three bcd data bytes. ( read/write). The bcd bytes referred to as sub-command.

Most read - modify -- write commands would use the last option.

EncoderCAT provides a CI-V user configuration system that supports these formats.

I got all this working on my IC7000 and then downloaded the manual for a modern Icom rig.

The hex + 3 BCD commands have a completely different numbering allocation.

... This doesn't matter

        - the user of EncoderCAT configures the eight encoders using the CAT manual for his/her rig.