Mitsubishi Electric MELSEC Q Series Handbook page 107

3
REPLACEMENT OF I/O MODULE
(39)Specifications comparison between A1SX81 (24VDC, negative common) and QX81-S2
Specifications
Number of input points
Isolation method
Rated input voltage
Rated input current
Operating voltage range
Maximum number of
simultaneous input points
On voltage/on current
Off voltage/off current
Input resistance
Off  on
Response
time
On  off
Common terminal
arrangement
Operation indication
External connection
system
Applicable wire size
Current consumption
External dimensions
Weight
*1 Check the specifications of the sensor or switches to be connected to the QX81-S2.
*2 The following shows the derating chart.
A1SX81
32 points
Photocoupler
12/24VDC
Approx. 3mA/Approx. 7mA
10.2 to 26.4VDC
(ripple ratio within 5%)
*2
Refer to the derating chart.
8VDC or more/2mA or more
4VDC or less/1mA or less
Approx. 3.3k
1ms/5ms/10ms/20ms/70ms or less
10ms or less
(24VDC)
1ms/5ms/10ms/20ms/70ms or less
10ms or less
(24VDC)
32 points/common
(common terminal: 17, 18, 36)
On indication (LED)
37-pin D-sub connector
(accessory)
2
0.3mm
0.08A (typ. all points on)
130(H)34.5(W)93.6(D)mm
0.24kg
(A1SX81)
26.4VAC
: Compatible,
Compat-
QX81-S2
32 points
Photocoupler
24VDC
Approx. 6mA
20.4 to 28.8VDC
(ripple ratio within 5%)
*2
Refer to the derating chart.
15VDC or more/3mA or more
5VDC or less/1.7mA or less
Approx. 3.6k
(Configure the setting in the PLC
parameter dialog box.)
10ms is set by default.
(Configure the setting in the PLC
parameter dialog box.)
10ms is set by default.
32 points/common
(common terminal: 17, 18, 36)
On indication (LED)
37-pin D-sub connector
(sold separately)
2
0.3mm (A6CON1E)
0.075A (typ. all points on)
98(H)27.4(W)90(D)mm
0.16kg
(QX81-S2)
(%)
100
90
80
70
On
60
ratio
50
40
30
20
10
0 10 20
Ambient temperature
: Partially changed, : Incompatible
Precautions for replacement
ibility



The rated input current is
*1
reduced.

Use it within the range shown in
the derating chart.
The on voltage/on current differ.
The off voltage/off current differ.
The input resistance is
*1
increased.

Set the input response time of
parameter to the default value
(10ms).



Existing external wiring can be

used.
Note that the connecting
direction of the connector is

inverted.

(31.25%) 24VDC
(18.75%) 28.8VDC
30 40 50 55
3
*1
*1
- 54