To provide main communication equipment securing a radio channel used for radio communication while radio wave interference of radio communication is suppressed.

In 89 DCL channels (dch1 to dch89), a plurality of (45, for example) DCL channels where radio wave interference with radio LAN channels (wch1 to wch14) included in a priority list with high priority is suppressed are selected with the DCL priority list in a priority table A (priority table B) as reference by MFP1. Since possibility that a band used in DCL radio communication 300 is overlapped with a band used in LAN radio communication 200 corresponding to the priority list with high priority can be reduced, possibility of radio wave interference with LAN radio communication 200 corresponding to the priority list with high priority is reduced, and DCL radio communication 300 is achieved with a DCL slave machine 61.

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