Description
For high-speed, precise voltage data acquisition within Sysmac automation architectures, the Omron NX-AD3608 provides four channels of high-resolution differential analog inputs. This unit integrates seamlessly into the NX-series I/O system, offering an exceptional resolution of 1/30000 and an ultra-fast conversion speed of 10 microseconds per point. Designed to process voltage signals from -10 to +10 VDC, it supports both synchronous I/O refreshing and free-run refreshing modes, ensuring precise synchronization with the host CPU or EtherCAT coupler unit. Secure, vibration-proof field wiring is achieved through the integrated 12-terminal screwless Push-In Plus terminal block.
Features
- Four differential analog input channels dedicated to voltage signals.
- Flexible voltage input range of -10 to +10 VDC with an input conversion range of -5% to 105%.
- High-speed conversion cycle of 10 microseconds per point for highly dynamic processes.
- Selectable synchronous I/O refreshing and free-run refreshing to match system requirements.
- Transformer and digital isolator isolation between the input channels and the internal NX bus.
- Toolless Push-In Plus (screwless clamping) 12-terminal block for rapid installation and wiring maintenance.
- Integrated TS status indicator for rapid local module diagnostics.
Applications
- High-speed closed-loop tension and pressure control systems.
- Real-time analog feedback monitoring in packaging and converting machinery.
- Precision position tracking using analog displacement sensors.
- Data acquisition setups requiring microsecond-level synchronization over EtherCAT networks.
Technical Specifications
| Manufacturer |
Omron |
| Model / Article Number |
NX-AD3608 |
| Series |
NX Series I/O |
| Input Type |
Analog Voltage |
| Number of Points |
4 points |
| Input Range |
-10 to +10 VDC |
| Resolution |
1/30000 |
| Conversion Time |
10 microseconds/point |
| Input Method |
Differential |
| Input Impedance |
1 MOhm minimum |
| Input Conversion Range |
-5% to 105% (full scale) |
| Absolute Maximum Rating |
+/-15 V |
| Overall Accuracy (25 degC) |
+/-0.1% (full scale) |
| Overall Accuracy (0 to 55 degC) |
+/-0.2% (full scale) |
| I/O Refreshing Method |
Switching synchronous I/O refreshing and Free-Run refreshing |
| Isolation Method |
Between input and NX bus: Power = Transformer, Signal = Digital isolator (no isolation between input channels) |
| Insulation Resistance |
20 MOhm minimum between isolated circuits (at 100 VDC) |
| Dielectric Strength |
510 VAC between isolated circuits for 1 minute (leakage current 5 mA max) |
| NX Unit Power Consumption |
1.45 W max (connected to CPU or CCU); 1.10 W max (connected to Coupler) |
| External Terminals |
Screwless clamping terminal block (12 terminals) |
| Dimensions (W x H x D) |
12 mm x 100 mm x 71 mm |
| Net Weight |
0.07 kg |
| Shipping Weight (Calculated) |
1.0 kg |
Connections and Interfaces
| Terminal |
Signal Name |
Terminal |
Signal Name |
| A1 |
V1+ (Input Voltage 1 +) |
B1 |
V3+ (Input Voltage 3 +) |
| A2 |
V1- (Input Voltage 1 -) |
B2 |
V3- (Input Voltage 3 -) |
| A3 |
V2+ (Input Voltage 2 +) |
B3 |
V4+ (Input Voltage 4 +) |
| A4 |
V2- (Input Voltage 2 -) |
B4 |
V4- (Input Voltage 4 -) |
| A5 |
NC (Not Connected) |
B5 |
NC (Not Connected) |
| A6 |
NC (Not Connected) |
B6 |
NC (Not Connected) |
Empirical Engineering Insights
Alternative Models & Compatibility
The NX-AD3608 is part of the Omron Sysmac ecosystem. When planning migrations or additions, ensure your NX1P2, NX102, or NJ-series CPU unit is running compatible firmware supporting high-speed synchronous I/O. Note that synchronous refreshing is only functional when this module is mounted adjacent to a CPU or an EtherCAT coupler (such as the NX-ECC203) that natively supports distributed clocks (DC).
Application Pitfalls & Engineering Notes
Because this module utilizes a differential input design without inter-channel isolation, all negative terminal connections (V1- through V4-) must remain within the common-mode voltage range. If there is a high potential difference between your signal source grounds, ground-loop current will flow, causing severe measurement errors or eventual hardware failure. Ensure that the signal sources are either completely floating or tied to a single common reference point before entering the module.
Commissioning & Wiring Tips
To protect the highly sensitive 1/30000 resolution, always use high-quality shielded twisted-pair (STP) cabling for all analog lines. Ground the cable shields at a single point on the functional ground bar of your control panel. For maximum noise immunity, route the analog signal cables in a dedicated wire duct isolated from three-phase power lines and variable frequency drive (VFD) output cables.
Installation Guidelines
CRITICAL WARNING
Disconnect all power sources to the NX Unit, CPU Unit, and any external I/O power lines before installing, removing, or wiring the module. Failing to completely de-energize the assembly can cause immediate equipment damage or unpredictable system behavior during commissioning.
1
Mount the NX-AD3608 onto the DIN rail by sliding the unit's guide hook firmly into place until you hear a solid click indicating that the slide lock has engaged.
2
Push the terminal block straight onto the front of the module until it locks securely into position. Check the mechanical alignment of the keys.
3
Prepare your solid wire or ferruled stranded wire, then insert it straight into the terminal hole. No screwdriver is required for standard Push-In Plus terminal operation.
4
Verify connection status using the Sysmac Studio software, observing the TS indicator LED state. A solid green light indicates normal communication and module health.