OMRON NX1P2 Hardware Debugging Guide

2.3 Multi voltage domain isolation

When NX units with different I/O voltages (such as 24V and 12V) are connected to the same CPU rack, an additional I/O power supply unit (NX-PF0xxx) must be inserted at the voltage boundary. This unit will cut off the I/O power bus, and external power supplies with different voltages can be used on the left and right sides.

Wiring Practice - Detailed Explanation of Unscrew Terminal Blocks

The input and output terminals of NX1P2 are both equipped with screwless clamping terminal blocks, which can be quickly wired. Be sure to comply with the following regulations.

3.1 Applicable wires and crimping terminals

Terminal type allows wire diameter, recommended crimping terminal stripping length

Ordinary terminal (below 2A) 0.08~1.5 mm ² (AWG 28~16) AI0,25-8/AI0,5-8 8~10 mm

Ordinary terminal (2~4A) 0.5~1.5 mm ² tinned stranded wire AI0,5-8/AI1,5-8 8~10 mm

Grounding terminal (FG) 2.0 mm ² AI2,5-10 10 mm

Use tinned stranded wire or crimped terminals with insulated sleeves. Direct insertion of bare stranded wire may result in poor contact.

Prohibit the use of two-pin ferro terminals.

Recommended crimping tools: Phoenix Contact CRIMPFOX 6 or Weidm ü ller PZ 6 Roto.

3.2 Wiring steps (screw free terminals)

Insert a straight screwdriver (recommended SZS 0.4 × 2.5 or XW4Z-00B) vertically into the release hole and feel the spring release.

Keep the screwdriver pressed down and insert the stripped wire into the terminal hole until the bare wire is no longer visible.

Pull out the screwdriver and gently pull the wire to confirm locking.

Attention: The insertion force should not exceed 30 N, and the screwdriver should not be tilted or twisted, otherwise the terminal block will be damaged.

3.3 Fixing of high current wires

When the current exceeds 2 A (such as shared terminals), the wire harness must be fixed to the tie holes on both sides of the terminal block using zip ties. The width of the cable tie is ≤ 4 mm and the thickness is ≤ 1.5 mm. The fixing range of the wire is within 30 mm from the terminal block.

3.4 Grounding

The functional grounding (FG) terminal must be grounded, with a resistance of ≤ 100 Ω, a wire diameter of ≥ 2.0 mm ², and a length of ≤ 20 m.

The DIN rail contact piece of the CPU unit is internally connected to the FG terminal, so the entire rail can be grounded after grounding. If anodized aluminum rails (insulation) are used, they need to be separately grounded or isolated using NX-AUX01 insulation gaskets.

Interpretation of Power on and LED Indicator Status

4.1 Power on timing sequence

After connecting the unit power, the CPU unit takes about 10-20 seconds to enter the ready to run state (the RUN indicator light flashes at 2-second intervals). in the meantime:

The NX unit outputs on the CPU rack are all OFF.

The output behavior of EtherCAT slave depends on the slave settings (usually hold or reset).

External communication (EtherNet/IP) not established.

Safety suggestion: Use system defined variables (such as _CMasterState) in the user program to confirm the establishment of EtherCAT communication before controlling the output.

4.2 Meaning of LED indicator lights

Meaning of LED color status

POWER green constant light power supply is normal

RUN green constantly on RUN mode, user program executing

RUN green 2-second interval flashing startup in progress

ERROR Red Always On Major Fault (CPU Error or WDT)

ERROR Red 1-second interval flashing partial fault or minor fault (control continues)

BUSY yellow always on built-in non-volatile memory access (power off prohibited)

SD BUSY yellow flashing SD card access in progress (power off/card removal prohibited)

SD PWR yellow on, SD card powered on

NET RUN (EtherCAT) green constant light process data communication is normal

NET ERR (EtherCAT) red flashing recoverable error

LINK/ACT (EtherCAT) yellow flashing data transmission and reception in progress

FAQ:

POWER not on: Check if the 24V power supply is connected and if the terminals are locked.

ERROR constantly on: usually due to CPU hardware failure or watchdog timeout. Attempt to power off and restart, if it still persists, replace the unit.

RUN keeps flashing and does not enter steady state: there is a startup error (such as NX unit configuration mismatch). Use Sysmac Studio for online diagnosis.

4.3 Instant power outage handling

The CPU unit can withstand a momentary power outage of 2-8 ms and continue to operate (with output voltage maintained). If this time is exceeded, it will be detected as power off, and the following operations should be performed:

Immediately stop I/O refresh and turn off all outputs.

Interrupt SD card access and uninstall.

Interrupt online editing (there will be an error message when powered on next time).

Record power interruption events.

If you need to automatically restart after the power is restored, you can set the "restart mode" through Sysmac Studio.

Common troubleshooting ideas

5.1 Using event logs to locate issues

NX1P2 records all errors as events, which can be viewed in the "Event Log" of Sysmac Studio. The events are divided into:

Major Fault: CPU stops and all outputs are turned off.

Partial Fault: A functional module (such as EtherCAT master) stops while others continue.