Toshiba V Series - Page 54

34
model 3000 DeviceNet Module Manual (DN311/DN311A)
Chapter 3 Preparations for Operation (Hardware)
3
Figure 3-11 Example of Single Power Terminal Connection
(4) Single Power Unit Central Connection
Shown below is an example of configuration where a network power unit is installed
at the center of a trunk line (thick cable) 240 meters in overall length. The current
consumption of each node is shown in the figure below.
The central location of the network power unit permits supply of the maximum current
in all directions of the network.
Figure 3-12 Example of Single Power Unit Central Connection
(a) Total current consumption of section 1
(a’) Total current consumption of section 2
(b) Overall power cable length of section 1 = Overall power cable length of section 2
= 120 m
(c) Maximum current that can be supplied to the cables based on Figure 3-10 =
About 2.56 A (Obtained by linear approximation of 100 to 150 m)
(d) Since the total current consumption is smaller than the maximum current, power
can be supplied to all the nodes by single power unit central connection.
(e) Install a network power unit with a rated current capacity of 0.65 A or more.
(Select one with an adequate capacity, considering the conditions of use.)
ネットワーク
電源供給装置
Node 1Node 1Node 1Node 1Node 1
電源タップ
200 m
V +−
V −
0.1A 0.15A 0.05A 0.25A 0.1A
a)
合計消費電流＝
0.1A + 0.15A + 0.05A + 0.25A + 0.1A
＝
0.65A
b) 電源供給の総延長 ＝ 200ｍ
c) 図 3.10 からケーブルに流せる最大電流 ＝ 1.53A
d)
合計消費電流 ＜ 最大電流なので、単一電源終端接続で全ノードに
電源を供給できる
e)
ネットワーク電源供給装置は定格電流が
0.65A
以上のものを使用
(
使用条件等を考慮して、十分余裕のあるものを選定する
)
Power tap
Network powe
r
supply unit
a) Total current consumption
b) Overall power cable length
c) Maximum current that can be supplied to the cables based on figure 3.10
d) Since the total current consumption is smaller than the maximum current,
power can be supplied to all the nodes by single power unit terminal
connection.
e) Install a network power unit with a rated current capacity of 0.65 A or more.
(Select one with an adequate capacity, considering the conditions of use.)
Node 6Node 5Node 4Node 1Node 2Node 3
ネットワーク
電源供給装置
電源
タップ
セクション
1
120 m
V
+−
0.1A 0.25A 0.2A V
−
0.15A 0.25A 0.15A
セクション
2
120 m
Section 1 Section 2
Power
tap
Network power
unit