| 摘要 |
PURPOSE:To make the radio line of a close loop line in the POS system where a master machine and satellite machines are connected by the close loop line. CONSTITUTION:A master machine 11a and satellite machines 11b to 11f are provided with radio units 12a to 12f different by transmission frequencies and reception frequencies respectively. The reception frequency of the uppermost satellite machine 11b is matched to the transmission frequency of the master machine 11a. Reception frequencies of the other satellite machines 11c to 11f are matched to transmission frequencies of satellite machines just above themselves. The reception frequency of the master machine 11a is matched to the transmission frequency of the lowermost satellite machine 11f. Thus, the radio cloose loop line is formed. |
