通过Modbus RTU进行简单的RD6006交互 用法： rd6006_op.pl [options] options: [-h] -- help; [-d] -- debug; [-m /dev/device] -- device file, default = /dev/ttyUSB0; [-u unit] -- modbus device unit, default=1; [-O=off] -- off power after mesurement; [-v v_set] -- in