Datasheet

22 Remote I/O
Digital I/O unit (with MIL connector)
Item Specifications
Model NX-MD6121-5 NX-MD6256-5
Name DC input/transistor output unit
Capacity 16 inputs/16 outputs
Output section (CN1)
Internal I/O common NPN PNP
Rated voltage 12 to 24 VDC 24 VDC
Operating load voltage 10.2 to 28.8 VDC 20.4 to 28.8 VDC
Maximum value of load
current
0.5 A/point, 2 A/NX unit
Maximum inrush current 4.0 A/point, 10 ms max.
Leakage current 0.1 mA max.
Residual voltage 1.5 V max.
ON/OFF response time 0.1 ms max./0.8 ms max. 0.5 ms max./1.0 ms max.
Input section (CN2)
Internal I/O common For both NPN/PNP
Rated input voltage 24 VDC (15 to 28.8 VDC)
Input current
*1
*1. Typical rated current at 24 VDC.
7 mA
ON voltage 15 VDC min.
ON current 3 mA min.
OFF voltage 5 VDC max.
OFF current 1 mA max.
ON/OFF response time 20 s max./400 s max
Input filter time No filter, 0.25 ms, 0.5 ms, 1 ms (default), 2 ms, 4 ms, 8 ms, 16 ms, 32 ms, 64 ms, 128 ms, 256 ms
Dielectric strength 510 VAC between isolated circuits for 1 minute at a leakage current of 5 mA max.
Insulation resistance 20 M min. between isolated circuits (at 100 VDC)
Isolation method Photocoupler isolation
Unit power consumption 0.70 W max. 0.75 W max.
I/O power supply method Supply from external source
I/O current consumption 30 mA max. 40 mA max.
Current capacity of I/O power
supply terminal
Without I/O power supply terminals
I/O refreshing method Switching synchronous I/O refreshing and free-run refreshing
Terminal block type 2 MIL connectors
20 terminals
Dimensions (W x H x D) 30 × 100 × 71 mm
Weight 105 g max. 110 g max.
Disconnection/short-circuit
detection
Not supported
Protective function Not supported With load short-circuit protection
Terminal wiring
Circuit layout
NX-MD6121-5
CN1 (left) output circuit
I/O power supply +
I/O power supply −
I/O power supply +
I/O power supply −
Internal circuits
COM0
COM0
+V0
+V0
OUT0
to OUT15
Connector
NX-MD6121-5
CN1 (left) output terminal
20
16
12
18
14
10
6
4
2
8
19
15
11
17
13
9
5
3
1
7
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
12 to 24 VDC
OUT00
OUT01
OUT02
OUT03
OUT04
OUT05
OUT06
OUT07
OUT08
OUT09
OUT10
OUT11
OUT12
OUT13
OUT14
OUT15
COM0
+V0
COM0
+V0
CN2 (right) input circuit
I/O power supply +
I/O power supply −
I/O power supply +
I/O power supply −
COM1
COM1
IN0
to
IN15
Connector
Input indicator
3.3 k

Internal circuits
CN2 (right) input terminal
1
5
9
3
7
11
15
17
19
13
2
6
10
4
8
12
16
18
20
14
24 VDC
IN15
IN14
IN13
IN12
IN11
IN10
IN09
IN08
COM1
NC
IN07
IN06
IN05
IN04
IN03
IN02
IN01
IN00
COM1
NC
NX bus
connector
(left)
NX bus
connector
(right)
NX bus
connector
(left)
NX bus
connector
(right)
Signal
name
Connector
pin
Signal
name
Signal
name
Connector
pin
Signal
name
• Be sure to wire both pins 3 and 4 (COM0) of CN1.
• Be sure to wire both pins 1 and 2 (+V0) of CN1.
• The polarity of the input power supply of CN2 can
be connected in either direction.
• Be sure to wire both pins 3 and 4 (COM1) of CN2,
and set the same polarity for both pins.