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NX-OD / OC

NX-series Digital Output Units

NX-OD / OC

A Wide Range of Digital Output Units from General Purpose use to High- Speed Synchronous Control

General Specification

Item Specification
Enclosure Mounted in a panel
Grounding method Ground to 100 Ω or less
Operating
environment
Ambient operating temperature 0 to 55°C
Ambient operating humidity 10% to 95% (with no condensation or icing)
Atmosphere Must be free from corrosive gases.
Ambient storage temperature -25 to 70°C (with no condensation or icing)
Altitude 2,000 m max.
Pollution degree 2 or less: Conforms to JIS B3502 and IEC 61131-2.
Noise immunity 2 kV on power supply line (Conforms to IEC61000-4-4.)
Overvoltage category Category II: Conforms to JIS B3502 and IEC 61131-2.
EMC immunity level Zone B
Vibration resistance *1 Conforms to IEC 60068-2-6.
5 to 8.4 Hz with 3.5-mm amplitude, 8.4 to 150 Hz, acceleration of
9.8 m/s2, 100 min each in X, Y, and Z directions
(10 sweeps of 10 min each = 100 min total)
Shock resistance *1 Conforms to IEC 60068-2-27. 147 m/s2, 3 times each in X, Y, and
Z directions
Applicable standards *2 cULus: Listed (UL508) or Listed (UL 61010-2-201),
ANSI/ISA 12.12.01,
EU: EN 61131-2 or EN 61010-2-201, C-Tick or RCM,
KC: KC Registration, NK, LR

*1 For the Relay Output Unit, refer to the Digital Input Unit Specifications.
*2 Refer to the OMRON website (http://www.ia.omron.com/support/models/index.html) or consult your OMRON
      representative for the most recent applicable standards for each model.

Digital Output Unit Specifications

Transistor Output Unit (Screwless Clamping Terminal Block 12 mm, Width)

NX-OD2154

Unit name Transistor Output Unit Model NX-OD2154
Number of points 2 points External connection
terminals
Screwless clamping terminal block
(8 terminals)
I/O refreshing
method
Output refreshing with specified time stamp
Indicators TS indicator,
output indicator
3186_sp_2_1
Internal I/O common NPN
Rated voltage 24 VDC
Operating load
voltage range
15 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 1 A/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
300 ns max./300 ns max.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Digital isolator isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from the NX bus Current capacity of
I/O power supply
terminal
IOV: 0.5 A/terminal max.,
IOG: 0.5 A/terminal max.
NX Unit power
consumption
• Connected to a CPU Unit
0.85 W max.
• Connected to a Communications
Coupler Unit
0.45 W max.
I/O current
consumption
30 mA max.
Weight 70 g max.
Circuit layout
3186_sp_2_2

This unit uses a push-pull output circuit.
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_2_3
Disconnection/
Short-circuit
detection
Not supported. Protective function Not supported.

NX-OD2258

Unit name Transistor Output Unit Model NX-OD2258
Number of points 2 points External connection
terminals
Screwless clamping terminal block
(8 terminals)
I/O refreshing
method
Output refreshing with specified time stamp
Indicators TS indicator,
output indicator
3186_sp_3_1
Internal I/O common PNP
Rated voltage 24 VDC
Operating load
voltage range
15 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 1 A/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
300 ns max./300 ns max.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Digital isolator isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from the NX bus Current capacity of
I/O power supply
terminal
IOV: 0.5 A/terminal max.,
IOG: 0.5 A/terminal max.
NX Unit power
consumption
• Connected to a CPU Unit
0.85 W max.
• Connected to a Communications
Coupler Unit
0.50 W max.
I/O current
consumption
40 mA max.
Weight 70 g max.
Circuit layout
3186_sp_3_2

This unit uses a push-pull output circuit.
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_3_3
Disconnection/
Short-circuit
detection
Not supported. Protective function With load short-circuit protection.

NX-OD3121

Unit name Transistor Output Unit Model NX-OD3121
Number of points 4 points External connection
terminals
Screwless clamping terminal block (12
terminals)
I/O refreshing
method
Selectable Synchronous I/O refreshing or Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_4_1
Internal I/O common NPN
Rated voltage 12 to 24 VDC
Operating load
voltage range
10.2 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 2 A/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.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from the NX bus Current capacity of
I/O power supply
terminal
IOV: 0.5 A/terminal max.,
IOG: 0.5 A/terminal max.
NX Unit power
consumption
• Connected to a CPU Unit
0.90 W max.
• Connected to a Communications
Coupler Unit
0.55 W max.
I/O current
consumption
10 mA max.
Weight 70 g max.
Circuit layout 3186_sp_4_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_4_3
Disconnection/
Short-circuit
detection
Not supported. Protective function Not supported.

NX-OD3153

Unit name Transistor Output Unit Model NX-OD3153
Number of points 4 points External connection
terminals
Screwless clamping terminal block (12
terminals)
I/O refreshing
method
Selectable Synchronous I/O refreshing or Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_5_1
Internal I/O common NPN
Rated voltage 24 VDC
Operating load
voltage range
15 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 2 A/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
300 ns max./300 ns max.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Digital isolator isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from the NX bus Current capacity of
I/O power supply
terminal
IOV: 0.5 A/terminal max.,
IOG: 0.5 A/terminal max.
NX Unit power
consumption
• Connected to a CPU Unit
0.90 W max.
• Connected to a Communications
Coupler Unit
0.50 W max.
I/O current
consumption
30 mA max.
Weight 70 g max.
Circuit layout
3186_sp_5_2

This unit uses a push-pull output circuit.
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_5_3
Disconnection/
Short-circuit
detection
Not supported. Protective function Not supported.

NX-OD3256

Unit name Transistor Output Unit Model NX-OD3256
Number of points 4 points External connection
terminals
Screwless clamping terminal block (12
terminals)
I/O refreshing
method
Selectable Synchronous I/O refreshing or Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_6_1
Internal I/O common PNP
Rated voltage 24 VDC
Operating load
voltage range
15 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 2 A/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
0.5 ms max./1.0 ms max.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from the NX bus Current capacity of
I/O power supply
terminal
IOV: 0.5 A/terminal max.,
IOG: 0.5 A/terminal max.
NX Unit power
consumption
• Connected to a CPU Unit
0.90 W max.
• Connected to a Communications
Coupler Unit
0.55 W max.
I/O current
consumption
20 mA max.
Weight 70 g max.
Circuit layout 3186_sp_6_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_6_3
Disconnection/
Short-circuit
detection
Not supported. Protective function With load short-circuit protection.

NX-OD3257

Unit name Transistor Output Unit Model NX-OD3257
Number of points 4 points External connection
terminals
Screwless clamping terminal block (12
terminals)
I/O refreshing
method
Selectable Synchronous I/O refreshing or Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_7_1
Internal I/O common PNP
Rated voltage 24 VDC
Operating load
voltage range
15 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 2 A/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
300 ns max./300 ns max.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Digital isolator isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from the NX bus Current capacity of
I/O power supply
terminal
IOV: 0.5 A/terminal max.,
IOG: 0.5 A/terminal max.
NX Unit power
consumption
• Connected to a CPU Unit
0.85 W max.
• Connected to a Communications
Coupler Unit
0.50 W max.
I/O current
consumption
40 mA max.
Weight 70 g max.
Circuit layout
3186_sp_7_2

This unit uses a push-pull output circuit.
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_7_3
Disconnection/
Short-circuit
detection
Not supported. Protective function With load short-circuit protection.

NX-OD3268

Unit name Transistor Output Unit Model NX-OD3268
Number of points 4 points External connection
terminals
Screwless clamping terminal block (16
terminals)
I/O refreshing
method
Switching Synchronous I/O refreshing and Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_19_1
Internal I/O common PNP
Rated voltage 24 VDC
Operating load
voltage range
15 to 28.8 VDC
Maximum value of
load current
2 A/point, 8 A/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
0.5 ms max./1.0 ms max.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA max.
I/O power supply
method
Supply from external source Current capacity of
I/O power supply
terminal
IOV: 2 A/terminal max.,
IOG: 2 A/terminal max.,
COM (+V): 4 A/terminal max.,
0V: 4 A/terminal max.
NX Unit power
consumption
• Connected to a CPU Unit
0.85 W max.
• Connected to a Communications
Coupler Unit
0.50 W max.
Current
consumption from
I/O power supply
20 mA max.
Weight 70 g max.
Circuit layout 3186_sp_19_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_19_3

• 0V has 2 terminals, so be sure to wire both terminals.
• COM (+V) has 2 terminals, so be sure to wire both terminals.
Disconnection/
Short-circuit
detection
Not supported. Protective function With load short-circuit protection.

NX-OD4121

Unit name Transistor Output Unit Model NX-OD4121
Number of points 8 points External connection
terminals
Screwless clamping terminal block (16
terminals)
I/O refreshing
method
Selectable Synchronous I/O refreshing or Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_8_1
Internal I/O common NPN
Rated voltage 12 to 24 VDC
Operating load
voltage range
10.2 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 4 A/Unit
Maximum inrush
current
4.0 A/point, 10 ms max.
Leakage current 0.1 mA
Residual voltage 1.5 V max.
ON/OFF response
time
0.1 ms max./0.8 ms max.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from the NX bus Current capacity of
I/O power supply
terminal
IOV: 0.5 A/terminal max.
NX Unit power
consumption
• Connected to a CPU Unit
0.90 W max.
• Connected to a Communications
Coupler Unit
0.55 W max.
I/O current
consumption
10 mA max.
Weight 70 g max.
Circuit layout 3186_sp_8_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_8_3
Disconnection/
Short-circuit
detection
Not supported. Protective function Not supported.

NX-OD4256

Unit name Transistor Output Unit Model NX-OD4256
Number of points 8 points External connection
terminals
Screwless clamping terminal block (16
terminals)
I/O refreshing
method
Selectable Synchronous I/O refreshing or Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_9_1
Internal I/O common PNP
Rated voltage 24 VDC
Operating load
voltage range
15 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 4 A/Unit
Maximum inrush
current
4.0 A/point, 10 ms max.
Leakage current 0.1 mA
Residual voltage 1.5 V max.
ON/OFF response
time
0.5 ms max./1.0 ms max.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from the NX bus Current capacity of
I/O power supply
terminal
IOG: 0.5 A/terminal max.
NX Unit power
consumption
• Connected to a CPU Unit
1.00 W max.
• Connected to a Communications
Coupler Unit
0.65 W max.
I/O current
consumption
30 mA max.
Weight 70 g max.
Circuit layout 3186_sp_9_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_9_3
Disconnection/
Short-circuit
detection
Not supported. Protective function With load short-circuit protection.

NX-OD5121

Unit name Transistor Output Unit Model NX-OD5121
Number of points 16 points External connection
terminals
Screwless clamping terminal block (16
terminals)
I/O refreshing
method
Selectable Synchronous I/O refreshing or Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_10_1
Internal I/O common NPN
Rated voltage 12 to 24 VDC
Operating load
voltage range
10.2 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 4 A/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.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from the NX bus Current capacity of
I/O power supply
terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
1.00 W max.
• Connected to a Communications
Coupler Unit
0.65 W max.
I/O current
consumption
20 mA max.
Weight 70 g max.
Circuit layout 3186_sp_10_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_10_3
Disconnection/
Short-circuit
detection
Not supported. Protective function Not supported.

NX-OD5256

Unit name Transistor Output Unit Model NX-OD5256
Number of points 16 points External connection
terminals
Screwless clamping terminal block (16
terminals)
I/O refreshing
method
Selectable Synchronous I/O refreshing or Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_11_1
Internal I/O common PNP
Rated voltage 24 VDC
Operating load
voltage range
15 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 4 A/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
0.5 ms max./1.0 ms max.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from the NX bus Current capacity of
I/O power supply
terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
1.10 W max.
• Connected to a Communications
Coupler Unit
0.70 W max.
I/O current
consumption
40 mA max.
Weight 70 g max.
Circuit layout 3186_sp_11_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_11_3
Disconnection/
Short-circuit
detection
Not supported. Protective function With load short-circuit protection.

Transistor Output Units (M3 Screw Terminal Block, 30 mm Width)

NX-OD5121-1

Unit name Transistor Output Unit Model NX-OD5121-1
Number of points 16 points External connection
terminals
M3 screw terminal block (18 terminals)
I/O refreshing
method
Switching Synchronous I/O refreshing and Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_20_1
Internal I/O common NPN
Rated voltage 12 to 24 VDC
Operating load
voltage range
10.2 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 5 A/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.
Dimensions 30 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA max.
I/O power supply
method
Supply from the external
source
Current capacity of
I/O power supply
terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
0.90 W max.
• Connected to a Communications
Coupler Unit
0.60 W max.
Current
consumption from
I/O power supply
30 mA max.
Weight 125 g max.
Circuit layout 3186_sp_20_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_20_3
Disconnection/
Short-circuit
detection
Not supported. Protective function Not supported.

NX-OD5256-1

Unit name Transistor Output Unit Model NX-OD5256-1
Number of points 16 points External connection
terminals
M3 screw terminal block (18 terminals)
I/O refreshing
method
Switching Synchronous I/O refreshing and Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_21_1
Internal I/O common PNP
Rated voltage 24 VDC
Operating load
voltage range
20.4 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 5 A/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
0.5 ms max./1.0 ms max.
Dimensions 30 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA max.
I/O power supply
method
Supply from external source Current capacity of
I/O power supply
terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
0.95 W max.
• Connected to a Communications
Coupler Unit
0.65 W max.
Current
consumption from
I/O power supply
30 mA max.
Weight 125 g max.
Circuit layout 3186_sp_21_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_21_3
Disconnection/
Short-circuit
detection
Not supported. Protective function With load short-circuit protection.

Transistor Output Units (MIL Connector, 30 mm Width)

NX-OD5121-5

Unit name Transistor Output Unit Model NX-OD5121-5
Number of points 16 points External connection
terminals
MIL connector (20 terminals)
I/O refreshing
method
Switching Synchronous I/O refreshing and Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_12_1
Internal I/O common NPN
Rated voltage 12 to 24 VDC
Operating load
voltage range
10.2 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 2 A/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.
Dimensions 30 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from external source Current capacity of
I/O power supply
terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
0.95 W max.
• Connected to a Communications Coupler Unit
0.60 W max.
Current
consumption from
I/O power supply
30 mA max.
Weight 80 g max.
Circuit layout 3186_sp_12_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_12_3
• Be sure to wire both pins 3 and 4 (COM).
• Be sure to wire both pins 1 and 2 (+V).
Disconnection/
Short-circuit
detection
Not supported. Protective function Not supported.

NX-OD5256-5

Unit name Transistor Output Unit Model NX-OD5256-5
Number of points 16 points External connection
terminals
MIL connector (20 terminals)
I/O refreshing
method
Switching Synchronous I/O refreshing and Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_13_1
Internal I/O common PNP
Rated voltage 24 VDC
Operating load
voltage range
20.4 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 2 A/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
0.5 ms max./1.0 ms max.
Dimensions 30 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supplied from external
source.
Current capacity of
I/O power supply
terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
1.00 W max.
• Connected to a Communications Coupler Unit
0.70 W max.
Current
consumption from
I/O power supply
40 mA max.
Weight 85 g max.
Circuit layout 3186_sp_13_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_13_3
• Be sure to wire both pins 1 and 2 (COM (+V)).
• Be sure to wire both pins 3 and 4 (0V).
Disconnection/
Short-circuit
detection
Not supported. Protective function With load short-circuit protection.

NX-OD6121-5

Unit name Transistor Output Unit Model NX-OD6121-5
Number of points 32 points External connection
terminals
MIL connector (40 terminals)
I/O refreshing
method
Switching Synchronous I/O refreshing and Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_14_1
Internal I/O common NPN
Rated voltage 12 to 24 VDC
Operating load
voltage range
10.2 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 2 A/common, 4 A/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.
Dimensions 30 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from external source Current capacity of
I/O power supply
terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
1.00 W max.
• Connected to a Communications Coupler Unit
0.80 W max.
Current
consumption from
I/O power supply
50 mA max.
Weight 90 g max.
Circuit layout 3186_sp_14_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_14_3
• Be sure to wire both pins 21 and 22 (+V0).
• Be sure to wire both pins 23 and 24 (COM0).
• Be sure to wire both pins 1 and 2 (+V1).
• Be sure to wire both pins 3 and 4 (COM1).
Disconnection/
Short-circuit
detection
Not supported. Protective function Not supported.

NX-OD6256-5

Unit name Transistor Output Unit Model NX-OD6256-5
Number of points 32 points External connection
terminals
MIL connector (40 terminals)
I/O refreshing
method
Switching Synchronous I/O refreshing and Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_15_1
Internal I/O common PNP
Rated voltage 24 VDC
Operating load
voltage range
20.4 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 2 A/common, 4 A/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
0.5 ms max./1.0 ms max.
Dimensions 30 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA
max.
I/O power supply
method
Supply from external source Current capacity of
I/O power supply
terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
1.30 W max.
• Connected to a Communications Coupler Unit
1.00 W max.
Current
consumption from
I/O power supply
80 mA max.
Weight 95 g max.
Circuit layout 3186_sp_15_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_15_3
• Be sure to wire both pins 21 and 22 (COM0 (+V)).
• Be sure to wire both pins 1 and 2 (COM1 (+V)).
• Be sure to wire both pins 23 and 24 (0V0).
• Be sure to wire both pins 3 and 4 (0V1).
Disconnection/
Short-circuit
detection
Not supported. Protective function With load short-circuit protection.

Transistor Output Units (Fujitsu Connector, 30 mm Width)

NX-OD6121-6

Unit name Transistor Output Unit Model NX-OD6121-6
Number of points 32 points External connection
terminals
Fujitsu connector (40 terminals)
I/O refreshing
method
Switching Synchronous I/O refreshing and Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_22_1
Internal I/O common NPN
Rated voltage 12 to 24 VDC
Operating load
voltage range
10.2 to 28.8 VDC
Maximum value of
load current
0.5 A/point, 2 A/common, 4 A/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.
Dimensions 30 (W) x 100 (H) x 71 (D) Isolation method Photocoupler isolation
Insulation
resistance
20 MΩ min. between isolated
circuits (at 100 VDC)
Dielectric strength 510 VAC between isolated circuits for
1 minute at a leakage current of 5 mA max.
I/O power supply
method
Supply from external source Current capacity of
I/O power supply
terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
1.10 W max.
• Connected to a Communications Coupler Unit
0.80 W max.
Current
consumption from
I/O power supply
50 mA max.
Weight 90 g max.
Circuit layout 3186_sp_22_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection diagram
3186_sp_22_3

• Be sure to wire both pins A9 and A19 (COM0).
• Be sure to wire both pins B9 and B19 (COM1).
• Be sure to wire both pins A10 and A20 (+V0).
• Be sure to wire both pins B10 and B20 (+V1).
Disconnection/
Short-circuit
detection
Not supported. Protective function Not supported.

Relay Output Unit (Screwless Clamping Terminal Block 12 mm, Width)

NX-OC2633

Unit name Relay Output Units Model NX-OC2633
Number of points 2 points, independent contacts External
connection
terminals
Screwless clamping terminal block (8
terminals)
I/O refreshing
method
Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_16_1
Relay type N.O. contact
Maximum
switching capacity
250 VAC/2 A (cosφ = 1),
250 VAC/2 A (cosφ = 0.4),
24 VDC/2 A, 4 A/Unit
Minimum
switching capacity
5 VDC, 1 mA
Relay service life Electrical: 100,000 operations *
Mechanical: 20,000,000 operations
ON/OFF response
time
15 ms max./15 ms max.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Relay isolation
Insulation
resistance
Between A1/B1 terminals and A3/B3
terminals: 20 MΩ min. (500 VDC)
Between the external terminals and
internal circuits: 20 MΩ min. (500
VDC)
Between the internal circuit and GR
terminal: 20 MΩ min. (100 VDC)
Between the external terminals and
GR terminal: 20 MΩ min. (500 VDC)
Dielectric
strength
Between A1/B1 terminals and A3/B3
terminals: 2300 VAC for 1 min at a
leakage current of 5 mA max.
Between the external terminals and
GR terminal: 2300 VAC for 1 min at a
leakage current of 5 mA max.
Between the external terminals and
internal circuits: 2300 VAC for 1 min
at a leakage current of 5 mA max.
Between the internal circuit and GR
terminal: 510 VAC for 1 min at a
leakage current of 5 mA max.
Vibration
resistance
Conforms to IEC60068-2-6.
5 to 8.4 Hz with amplitude of 3.5 mm,
8.4 to 150 Hz, acceleration of 9.8
m/s2
100 min each in X, Y, and Z
directions
(10 sweeps of 10 min each = 100 min
total)
Shock resistance 100 m/s2, 3 times each in X, Y, and
Z directions
I/O power supply
method
Supply from external source Current capacity
of I/O power
supply terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
1.20 W max.
• Connected to a Communications Coupler Unit
0.80 W max.
I/O current
consumption
No consumption
Weight 65 g max.
Circuit layout
3186_sp_16_2

You cannot replace the relay.
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection
diagram
3186_sp_16_3
Disconnection/
Short-circuit
detection
Not supported. Protective
function
Not supported.

* Electrical service life will vary depending on the current value. Refer to "NX-series Digital I/O Units User’s Manual" for details.

Relay Output Unit

NX-OC2733

Unit name Relay Output Unit Model NX-OC2733
Number of points 2 points, independent contacts External
connection
terminals
Screwless clamping terminal block (8
terminals)
I/O refreshing
method
Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_17_1
Maximum
switching capacity
250 VAC/2 A (cosφ = 1),
250 VAC/2 A (cosφ = 0.4),
24 VDC/2 A,
4 A/Unit
Minimum
switching capacity
5 VDC, 10 mA
Relay service life Electrical: 100,000 operations
Mechanical: 20,000,000 operations
ON/OFF response
time
15 ms max./15 ms max.
Dimensions 12 (W) x 100 (H) x 71 (D) Isolation method Relay isolation
Insulation
resistance
Between A1/3, B1/3 terminals and
A5/7, B5/7 terminals: 20 MΩ min.
(at 500 VDC)
Between the external terminals and
functional ground terminal: 20 MΩ
min. (at 500 VDC)
Between the external terminals and
internal circuits: 20 MΩ min. (at 500
VDC)
Between the internal circuit and the
functional ground terminal: 20 MΩ
min. (at 100 VDC)
Dielectric
strength
Between A1/3, B1/3 terminals and
A5/7, B5/7 terminals: 2300 VAC for
1 min at a leakage current of 5 mA
max.
Between the external terminals and
the functional ground terminal: 2300
VAC for 1 min at a leakage current
of 5 mA max.
Between the external terminals and
internal circuits: 2300 VAC for 1 min
at a leakage current of 5 mA max.
Between the internal circuit and the
functional ground terminal: 510 VAC
for 1 min at a leakage current of 5
mA max.
I/O power supply
method
Supply from external source Current capacity
of I/O power
supply terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
1.30 W max.
• Connected to a Communications
Coupler Unit
0.95 W max.
Current
consumption from
I/O power supply
No consumption
Weight 70 g max.
Circuit layout 3186_sp_17_2
NO0 and NO1 are normal open contacts, and NC0 and NC1 are normal close contacts.
You cannot replace the relay.
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: No restrictions
Terminal
connection
diagram
3186_sp_17_3
Disconnection/
Short-circuit
detection
Not supported. Protective
function
Not supported.

Relay Output Units (Screwless Clamping Terminal Block, 24 mm Width)

NX-OC4633

Unit name Relay Output Unit Model NX-OC4633
Number of points 8 points, independent contacts External
connection
terminals
Screwless clamping terminal block
(8 terminals x 2)
I/O refreshing
method
Free-Run refreshing
Indicators TS indicator,
output indicator
3186_sp_23_1
Relay type N.O. contact
Maximum
switching capacity
250 VAC/2 A (cosφ = 1),
250 VAC/2 A (cosφ = 0.4),
24 VDC/2 A,
8 A/Unit
Minimum
switching capacity
5 VDC, 1 mA
Relay service life Electrical: 100,000 operations*
Mechanical: 20,000,000 operations
ON/OFF response
time
15 ms max./15 ms max.
Dimensions 24 (W) x 100 (H) x 71 (D) Isolation method Relay isolation
Insulation
resistance
Between output bits: 20 MΩ min.
(at 500 VDC)
Between the external terminals
and the functional ground terminal:
20 MΩ min. (at 500 VDC)
Between the external terminals and
internal circuits: 20 MΩ min.
(at 500 VDC)
Between the internal circuit and the
functional ground terminal: 20 MΩ
min. (at 100 VDC)
Dielectric
strength
Between output bits: 2300 VAC for
1 min at a leakage current of 5 mA
max.
Between the external terminals and
the functional ground terminal: 2300
VAC for 1 min at a leakage current
of 5 mA max.
Between the external terminals and
internal circuits: 2300 VAC for 1 min
at a leakage current of 5 mA max.
Between the internal circuit and the
functional ground terminal: 510 VAC
for 1 min at a leakage current of 5 mA
max.
Vibration
resistance
Conforms to IEC 60068-2-6.
5 to 8.4 Hz with amplitude of 3.5 mm,
8.4 to 150 Hz, acceleration of 9.8 m/s2
100 min each in X, Y, and Z directions
(10 sweeps of 10 min each = 100 min
total)
Shock resistance 100 m/s2, 3 times each in X, Y, and Z directions
I/O power supply
method
Supply from external source Current capacity
of I/O power
supply terminal
Without I/O power supply terminals
NX Unit power
consumption
• Connected to a CPU Unit
2.00 W max.
• Connected to a Communications
Coupler Unit
1.65 W max.
Current
consumption from
I/O power supply
No consumption
Weight 140 g max.
Circuit layout 3186_sp_23_2
Installation
orientation and
restrictions
Installation orientation:
• Connected to a CPU Unit: Possible in upright installation.
• Connected to a Communications Coupler Unit: Possible in 6 orientations.
Restrictions: As shown in the following.
3186_sp_23_3
Terminal
connection
diagram
3186_sp_23_4

* Electrical service life will vary depending on the current value. Refer to "NX-series Digital I/O Units User’s Manual" for details.

Version Information

Connecting with CPU Units

Refer to the user's manual for the CPU Unit for the CPU Unit to which NX Units can be connected.

NX Units Corresponding versions *
Model Unit Version CPU Unit Sysmac Studio
NX-OD2154 Ver.1.0 Ver.1.13 or later Ver.1.17 or higher
NX-OD2258
NX-OD3121
NX-OD3153
NX-OD3256
NX-OD3257
NX-OD3268
NX-OD4121
NX-OD4256
NX-OD5121
NX-OD5121-1
NX-OD5121-5
NX-OD5256
NX-OD5256-1
NX-OD5256-5
NX-OD6121-5
NX-OD6121-6
NX-OD6256-5
NX-OC2633
NX-OC2733
NX-OC4633

* Some Units do not have all of the versions given in the above table. If a Unit does not have the specified version, support is provided by the oldest available version after the specified version. Refer to the user's manuals for the specific Units for the relation between models and versions.

Connecting with Coupler Units

NX Units Corresponding versions *1
Model Unit Version EtherCAT EtherNet/IP
Communications
Coupler Unit
NJ/NX-series
CPU Units or
NY-series
Industrial PCs
Sysmac
Studio
Communications
Coupler Unit
Sysmac
Studio
NX-OD2154 Ver.1.0 Ver.1.1 or later Ver.1.06 or later
*2
Ver.1.07 or
higher
--- ---
NX-OD2258
NX-OD3121 Ver.1.0 or later Ver.1.05 or later Ver.1.06 or
higher
Ver.1.0 or later Ver.1.10 or
higher
NX-OD3153
NX-OD3256
NX-OD3257
NX-OD3268 Ver.1.13 or
higher
Ver.1.13 or
higher
NX-OD4121 Ver.1.06 or
higher
Ver.1.10 or
higher
NX-OD4256
NX-OD5121
NX-OD5121-1 Ver.1.13 or
higher
Ver.1.13 or
higher
NX-OD5121-5 Ver.1.10 or
higher
Ver.1.10 or
higher
NX-OD5256 Ver.1.06 or
higher
NX-OD5256-1 Ver.1.13 or
higher
Ver.1.13 or
higher
NX-OD5256-5 Ver.1.10 or
higher
Ver.1.10 or
higher
NX-OD6121-5
NX-OD6121-6 Ver.1.13 or
higher
Ver.1.13 or
higher
NX-OD6256-5 Ver.1.10 or
higher
Ver.1.10 or
higher
NX-OC2633 Ver.1.06 or
higher
NX-OC2733 Ver.1.08 or
higher
NX-OC4633 Ver.1.17 or
higher
Ver.1.17 or
higher

*1 Some Units do not have all of the versions given in the above table. If a Unit does not have the specified version,
      support is provided by the oldest available version after the specified version. Refer to the user's manuals for the
      specific Units for the relation between models and versions.
*2 If you use a CPU Unit, the instructions for time stamp refreshing are supported by CPU Units with unit version 1.06
      or later. If you do not use instructions for time stamp refreshing, you can use version 1.05. Refer to the instructions
      reference manual for the connected CPU Unit or Industrial PC for details on the instructions for time stamp refreshing.