Power-On/Off Timing - Mitsubishi Electric FX3U-128ASL-M User Manual

FX -128ASL-M User's Manual
3U
5) Example of power supply calculation
Calculation to check whether a system having the following conditions can be constructed.
Condition 1: Cross-sectional area of transmission cables: 0.75 mm
Condition 2: Total length: 50 m
Condition 3: Non-isolated slave module (Input ASLINKER)
Condition 4: Connected load to the slave module (three-wire sensor)
Condition 5: Power supply for the 128ASL-M
Checking the calculation formulas [1] to [3]
[1] I(A) = (Ihin(A) × m) ≤ The maximum transmission cable supply current
From conditions [1] and [2], the maximum transmission cable supply current is 0.96 A.
From conditions [3] and [4], the current consumption "Ihin (A) × m" of 10 non-isolated slave
modules is as follows:
I(A) = 0.720 A ≤ 0.96 A
[2] Vm(V) - ∆V(V) ≥ 20 V
From conditions [1] and [2], the voltage drop "∆V (V)" between lines is as follows:
From condition [5], the power supply "Vm (V)" for the 128ASL-M is 24 V.
24 V - 1.8 V = 22.2 V ≥ 20 V
[3] Vm(V) - ∆V(V) ≥ The lowest allowable voltage of the connected load (21.6 V)
22.2 V ≥ 21.6 V
Based on the calculation results [1] to [3] above, this system can be constructed.
5.6

Power-ON/OFF timing

The AnyWireASLINK system external power supply should be turned ON simultaneously with or before the
power supply of the PLC main unit it is connected to.
(The order is inverted when the system is powered OFF.)
Caution
If the PLC main unit is powered ON before the 24 V DC external power supply in the AnyWireASLINK system,
a transmission cable voltage drop detection error may occur.
If the error including transmission cable voltage drop detection error is detected, the error can be cleared by
turning the error flag clear command (BFM#27 b0) from OFF to ON.
Number of I/O points: 4 points
Module current consumption: 20 mA
Number of modules: 10 units
Three-wire sensor currentconsumption: 13 mA
Number of sensors: 4 per module
Power supply voltage: 24 V DC ± 10%
Power supply voltage: 24 V DC
(0.020 + (0.013 × 4)) × 10 = 0.720 A
0.720 × 50 × 0.025 × 2 = 1.8V
5 Wiring, Power-ON/OFF Timing
5.6 Power-ON/OFF timing
2
(Conductor resistance 0.025 Ω/m)
→ Satisfied
→ Satisfied
→ Satisfied
1
2
3
4
5
6
7
8
9
A
39