Broken Unit Examination (Dividing Network Examination)

When you cannot quickly find the trouble point due to a broken unit, connection failure including loose connector, or cable partial disconnection, divide the network to find the trouble point. Verify how error occurrence conditions change while taking the following countermeasures.

• Examination Method
  Divide the network to find which node is the cause of the problem.
  Verify that a master can establish communications with the slaves even though one slave is separated from the network.
  After finding the problem node, check the cables connected to it and replace the unit.

• How to Divide
  To divide the network, follow either procedure described below depending on the cable layout.

  • Separating each block from the network
    Divide the network by block and check each block.

  1. Ensure that the master has no problem by connecting it to its slaves one by one. (MS/NS: green light ON)

  2. Divide the network in the middle of it and check for the communication condition. (MS/NS: green light ON)
     Normal: The trouble point is on the other half of the network.
     Error: The trouble point is on the current half of the network.

  3. Check for communication on the block to specify the trouble point.
     

• Separate each slave from the network
  Check each slave.
  The trouble point is where error condition changes into normal condition.