FP2−CCUConfirming Unit Settings and Design Contents3 − 63.2 Confirming the I/O Allocation and Root No.3.2.2 Confirming Root No.If multiple Computer Communication Units have been installed, they are labeled “RootNo. 1”, “Root No. 2”, and “Root No. 3” in sequential order, starting from the unit closestto the CPU unit.Root numbers are not used directly in the handling of the Computer Communication Unit,but if a Multi−wire Link Unit is being used at the same time, these numbers aresometimes specified on the Multi−wire Link Unit side.Example:When two Multi−wire Link Units and one ComputerCommunication Unit are being installedMulti−wire Link Unit(MEWNET−W mode)Computer Communication UnitRoot No. 1Root No. 2Root No. 3If a Multi−wire Link Unit set to the MEWNET−W mode has also beeninstalled, the root numbers are set so that the Multi−wire Link Unit is alsoincluded.Tip