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MELSEC-Q 
2   INPUT MODULE SPECIFICATIONS 
2.17 QX72 DC Input Module (Positive/Negative Shared Common Type) 
Type 
Specifications 
DC input module (Positive/negative shared common  type) 
QX72 Appearance 
Number of input points  64 points 
 
Isolation method  Photocoupler 
Rated input voltage 
5VDC  
(+20/-10%, ripple ratio within 5%) 
12VDC  
(+20/-15%, ripple ratio within 5%) 
Rated input current  Approx. 1.2mA  Approx. 3.3mA 
Input derating  None 
ON voltage/ON current  3.5V or higher/3mA or higher 
OFF voltage/OFF current  1V or lower/0.1mA or lower 
Input resistance  Approx. 3.3kΩ 
Response 
time 
OFF to ON 
1ms/5ms/10ms/20ms/70ms or less (configured in PLC parameter) 1  
(Default: 10ms) 
ON to OFF 
1ms/5ms/10ms/20ms/70ms or less (configured in PLC parameter) 1  
(Default: 10ms) 
Dielectric withstand voltage  560VAC rms/3 cycles (altitude 2000m) 
Insulation resistance  10MΩ or more by insulation resistance tester 
Noise immunity 
By noise simulator of 500Vp-p noise voltage, 
1 s noise width and 25 to 60Hz noise frequency 
First transient noise IEC61000-4-4: 1kV 
Protection degree  IP2X 
Common terminal arrangement  32 points/common (common terminal: 1B01, 1B02, 2B01, 2B02) 
Number of occupied I/O points  64 points (I/O assignment is set as a 64-point input module.) 
Operation indicator  ON indication (LED), 32-point switchover using switch 
External connections  40-pin connector 
Applicable wire size 
0.088 to 0.3mm
2
 (For A6CON1 or A6CON4) 2 
Applicable connector  A6CON1, A6CON2, A6CON3, A6CON4 (optional) 
Internal current consumption 
(5VDC) 
85mA (TYP, all points ON) 
(0.09A is shown on the rating plate of the module.) 
Weight 0.13kg 
 
1: For the setting method, refer to Section 1.3.1. 
2: When using A6CON2 and A6CON3, refer to Chapter 7. 
 
QX72
QX72
DISPLAY
F L
01234567
8 9 ABCDEF
01234567
8 9 ABCDEF
5/12VDC
1.2/3.3mA