xCAT - Icom CI-V configuration

Icom CI-V uses CAT byte sequences are that specified in hexadecimal:

Hexadecimal bytes are represented in this document 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:

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

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

Below is a development IC7000 configuration.  Editing is performed directly on the grid.

This display is obtained by either Read from EncoderCAT  or   Load from file.

Note that hexadecimal values are shown in green.

Icom CI-V   -  configuration field details

Fields:   subcom type,  send / read, and encoder mode are option selectors. eg: subcom type as shown here. The selectors are drop down lists located in the grid.

A full explanation of these fields is on the following page.

 CI-V command byte sequence is as below ( rig addr and EncoderCAT addr swap place in data from the radio);

byte 0


  byte 2

   byte 3

byte 4

0 - 3 bytes

   0 to 5 bytes

end (oblig)



rig addr

  EncoderCAT addr


sub com

   data bytes


Note that subcom, if present is specified as a single hex byte or two or three bcd bytes.

Summary of configuration data fields;  
( CAT value is the numeric read from and written back to the radio. It may differ from the OLED display)

                                        eg; 500114 decimal  ... transmitted as hex bytes 0x05   0x01   0x14  

RS232 parameters:  Baudrate, bits/char, stop bits and parity must match the settings on the radio.

Display panel is left unchecked if there is no OLED display.  

Display contrast for SSD1306 display drivers has range 0-255.

Title is used  to identify the configuration. ( 27 chars max.  Lookups have a separate title.)