| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a terminal resistor at both ends of a communication line in any state of use, and to discriminate a control device of a left unit or a right unit from a control device on an operation room side.SOLUTION: An upper revolving body 3 consists of a revolving frame 11 and first and second units 14, 16 detachable at left or right. A communication system includes a first communication line 61 connected to operation room side control devices 53a, 53b and a control device 25 of a first unit, with a terminal resistor 62 connected to one end, a second communication line 63 which is connected to the operation room side control device, with a terminal resistor 64 connected to one end, a first connector 65 connected to the first and second communication lines, third-fifth communication lines 66-68 on the revolving frame, a second connector 69 connected to the third/fourth communication lines, a third connector 71 connected to the third/fifth communication lines, terminal resistors 72, 73 connected to the fourth/fifth communication lines, a sixth communication line 74 connected to a control device 35 of the second unit, and a fourth connector 75.</p> |
