Mitsubishi Electric MELSEC iQ-F FX55-ASL-M User Manual page 46

Description of conditions 2 and 3
■Vm: Supply voltage for the FX5-ASL-M
• Voltage: 21.6 to 27.6 V DC (24 V DC -10 to +15%), ripple voltage 0.5 Vp-p or lower
• Recommended voltage: 26.4 V DC (24 V DC +10%)
■V(V): Cable-to-cable voltage drop
Calculation formula
V(V) = Transmission cable supply current I(A)  Cable resistance R
()
Calculation example
The example shows how to check whether the total length of 100 m is sufficient to configure a system in the following
conditions.
■Condition
Item
Non-isolation slave module (Input ASLINKER)
Connected load (three-wire sensor)
Transmission cable (DP, DN)
Supply voltage for the FX5-ASL-M
■Calculation result
Item Calculation formula
I(A) = (Ihin  m) = I(A)  The maximum transmission cable supply current
Condition 1
 (0.015 + (0.013  2))  24 = 0.984 A  1 A
Vm(V) - V(V)  20 V
Condition 2
 24 - (0.984  100  0.015  2) = 24 - 2.95 = 21.05 V  20 V
Vm(V) - V(V)  The lowest allowable voltage of the connected load
Condition 3
 The lowest limit of the allowable voltage range for connected load = 24 - 24  0.1 = 21.6V
 21.05 V < 21.6 V
The calculation results of the conditions 1) to 3) show that the system cannot be configured.
However, the system can be configured if the power supply for the FX5-ASL-M is changed to 24.55 V DC or higher.
5 SYSTEM CONFIGURATION
44
5.2 Power Supply to the AnyWireASLINK System
Description
■Transmission cable supply current (I(A))
Page 43 Transmission cable supply current (I(A))
■Cable resistance R ()
= Cable length (m)  Conductor resistance (/m)  2
• Wire diameter 1.25   Conductor resistance 0.015 /m
• Wire diameter 0.75   Conductor resistance 0.025 /m
Number of I/O points
Module current consumption
Number of modules
Three-wire sensor current
consumption
Number of sensors
Power supply voltage
Wire diameter
Power supply voltage
Description
2 points
15 mA
24
13 mA
2
24 V DC 10%
1.25 
24 V DC
Result
Satisfied
Satisfied
Not satisfied