IC7100 CAT connection for remoterig

If you want to operate remotely with your PC connected to the RRC control side (RRC-CP for the rest of article), you need to add a CAT interface throught the RRC radio (RRC-R for the rest of article) and the IC7100 radio.

The most simple way, but also the most expansive $$$ one, is to buy the ICOM CT-17 C-IV interface.

The other possibility is to buy a simple CT17 (not original) CAT connector. It usually is composed by an USB plug (with some converter IC inside) and a 3.5mm jack for the radio connetion. Take care to this, infact 1) there are no USB port at the remoterig side and 2) the levels are not properly converted from/to the remoterig logic level.

So the solution is simply use a TTL-RS232 converter externally supplied. So I just buy a very pretty pcb here at Artekit Shop that it is supplied also within the enclosure (on request).

And I connected to the male 3.5mm jack directly using the RXD and the TXD pad:

  • the  TXD and RXD must be connected both to the central tip of the plug
  • and GND to the shaft of the plug

As power supply for the VCC and the GND of the board I used the 5V taken from a USB cable.

Of course the remoterig must be programmed accordly. These are the settings of RRC-CP.

COM2 mode
COM2 baudrate
COM2 data bits
COM2 stop bits
COM2 parity
COM2 terminator (hex)
Use USB Com Port as COM2

The COM2 is referred to the serial port in the remoterig device.

The last row of the options table indicates that you can connect the RRC-CP front USB port directly to your PC. On the PC you must select the corresponding COM port after installing the microbit serial driver. Usually the driver installs four virtual serial ports called RRC1258 COM0 COM1 COM2 COMEXTRA. Then simply locate the “RRC1258 COM2” to which COM on the PC is assigned and use that value.

In the program you use for control you just need to set this com port with 9600 8n1 speed (I tried it with a faster speed but it doesn’t seem so reliable and also not necessary), 88h is the default terminator code.

From the software side I tested with HRD deluxe, BBLogger, N1MM+, MTTY and some other software for digital mode without problem.

If you have any feedback, please feel free to send me.

My acknowledgement goes to Charlie KB8CR that suggested to me this approach.

5 replies on “IC7100 CAT connection for remoterig”

Ciao !… a proposito dell’interfaccia TTL/RS-232. Hai descritto il settings da fare sull’unità RRC-1258 (quale ? quella di Control o quella Radio ?). Scusa la domanda banale, ma utilizzando la USB frontale come COM-2 dal Control, mi pare che sia poi l’unità RRC-1258 (Radio) dove dovrà essere inserito il convertitore di livello… o sbaglio ?. Però non ho ancora capito se viene utilizzata la com-2 o altra porta. Insomma, tiro a indovinare. La USB sull’unità di Control settata per COM-2 e collegata con cavo USB al PC…. il convertitore TTL/RS-232 sulla COM-2 dell’unità RRC-1258 Radio. Se è tutto vero…. scusa la retorica, dove andrò a “pescare” i 5Vdc per l’alimentazione ?. Grazie della eventuale risposta.

Ho aggiornato l’articolo chiarendo meglio quando stiamo parlando del RRC lato pannello (RRC-CP) o lato Radio (RRC-R).
Si il convertitore va attaccato dal lato della RRC-Radio perchè poi andrà inserito nella porta cat del modulo radio ICOM.
Come descritto per l’alimentazione dei 5v ho utilizzato uno spezzone di cavo già intestato con il connettore usb (ad esempio un vecchio cavo di un mouse) e poi l’ho collegato ad un normale alimentatore per i telefoni USB (me ne avanzava qualcuno). Altrimenti ci puoi dedicare direttamente un alimentatore a 5v.

Hi Andrea!, Thanks for the reply.
In my case I inserted an L7805 inside the RRC-1258 Radio unit in order not to compromise the delicacy of the black Box. The voltage stabilized at 5V to supply the interface was then fed to PIN 4 (DTR) of COM2, which as you know on the PCB is deactivated by the manufacturer for marketing reasons.

I’m not aware about the pin4 and the marketing reason. Could you explain this point more in details, it seems very interesting. Thanks

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