Omron DEVICENET - Section 3 Communications Power Supply Methods; Section 3; Communications Power Supply Methods

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SECTION 3
Communications Power Supply Methods
This section explains the various considerations involved in providing a communications power supply.
3-1 Basic Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
3-2 Flowchart: Determining Power Supply Requirements . . . . . . . . . . . . . . . . . . 89
3-2-1 Communications Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
3-3 Locating the Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
3-3-1 Power Supply Layout Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
3-3-2 Main Factors for Determining the Power Supply Location . . . . . . . 91
3-3-3 Calculating the Power Supply Location . . . . . . . . . . . . . . . . . . . . . . 91
3-4 Step 1: Evaluating the Configuration with Graphs . . . . . . . . . . . . . . . . . . . . . 92
3-4-1 Simple Evaluation of Power Supply Location from a Graph . . . . . . 93
3-4-2 Modifying the Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
3-5 Step 2: Evaluating the Configuration with Calculations. . . . . . . . . . . . . . . . . 96
3-5-1 Formulae for Calculating the Voltage Drop . . . . . . . . . . . . . . . . . . . 97
3-5-2 Modifying the Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
3-6 Step 3: Splitting the System into Multiple Power Supplies . . . . . . . . . . . . . . 101
3-6-1 Splitting the Power Supply System . . . . . . . . . . . . . . . . . . . . . . . . . 101
3-6-2 Configuration of the Power Supply Tap . . . . . . . . . . . . . . . . . . . . . . 101
3-6-3 Internal Circuits in the Power Supply Tap . . . . . . . . . . . . . . . . . . . . 101