YASKAWA DX200 Instructions Manual page 65

165626-1CD
JARCR-XFB01B Board
for DeviceNet
7 Connections for DeviceNet Communications
7.1 Location of Communication Power Supply
II) When the communications power supply is also used as the
internal circuit power supply
Because the allowable voltage range of the communications
power supply is different from that of the internal circuit power
supply as shown below, avoid using the power supply for both
communications and the internal circuit.
• Allowable voltage range for the communications power
supply: 11VDC to 25VDC
• Allowable voltage range for the internal circuit power sup-
ply: 24VDC - 15% to + 10%
Check the distance between the power supply and each node
in addition to the total current consumption for the
communications unit and the internal circuit of each node.
If these values satisfy the following equation, sufficient power
can be supplied to the node.
However, the current must not exceed the maximum allowable
current to the cable, 8A for a thick cable and 3A for a thin
cable.
Equation  [(Ln  Rc + Nt  0.005)  In]  0.65V
Ln :Distance between the power supply and a node
(excluding the length of the drop line)
Rc :Maximum resistance of the cable (0.015 /m for a thick
cable, 0.069 /m for a thin cable)
Nt :Number of adapters between the power supply and a
node
In :Current consumption required for the communications
unit and the internal circuit of a node
0.005= Contact resistance value of an adapter
(2) Corrective actions
If the obtained values do not satisfy the equation, consider the fol-
lowing corrective actions.
• Place a node with a large current consumption close to the
power supply.
• Move the power supply to the middle of the trunk line so
that the nodes are located on both sides of the power sup-
ply.
• When nodes are located on both sides of the power supply,
move the power supply to the side where the bigger power
supply capacity is required.
• When a thin cable is used, replace it with a thick cable.
7-8
HW1481973
65/70