I have done it and lunched dsd+ from it but I cannot see that any frequency is registered in the event log file. I guess it has to be any information in the frequency file, right?
I don't know if the frequency file matters. I randomly type freqs into FMP24 and if there is digital activity on the freq that DSDPlus decodes, it shows the freq in the event log. Are you using FMP24 with DSDPlus?
2022/07/11 16:01:48 Freq=171.625000 NAC=4F9 Group call; TG=1 RID=1 [?] 9s
2022/07/11 16:04:03 Freq=171.625000 NAC=4F9 Group call; TG=1 RID=250 [Fire Island 250] Pri0 3s
2022/07/11 16:04:09 Freq=171.625000 NAC=4F9 Group call; TG=1 RID=1 [?] 4s
2022/07/11 16:04:12 Freq=171.625000 NAC=4F9 Group call; TG=1 RID=250 [Fire Island 250] Pri0 7s