Mitsubishi Electric Melsec A Series - Page 26

2. SYSTEM CONFIGURATION
-------------------- MELSEC-A
(7) If two or more I/O modules are connected to one power supply, choose
cables and wiring route considering voltage
drop caused by cables.
The figure below explains
the voltage drop caused by cables.
V2
I
I
/
\
I
,
0---)
Stabilized
/
power supply
11 + 12
12
\
1/
1/
-,
I
Rl
R2
I I
I,
12
I
I/O module 1
I/O module
2
V1 Voltage drop between stabilized power supply and I/O module 1
V2 VoRage drop between I/O module 1 and I/O module 2
R1 Resistancebetween stabilized power supply and 110 module 1
R2 Resistance between I/O module 1 and I/O module 2
h Current consumption of I/O module 1
12 Current consumption of I/O module 2
!Voltage drop calculation I
VI = Rl x (11 + 12)
V2 = R2X 12
I Receiving port voltage of I/O module I
(Receiving port voltage of I/O module 1)
= (Voltage of stabilized power supply) - VI
(Receiving port voltage of I/O module 2)
= (Voltage of stabilized power supply) - VI - V2
An I/O module can be connected if the receiving portvoltage of I/O module
is higher than
the rated voltage of the I/O module to be used.
2-7
•