Item Specification
Enclosure Mounted in a panel
Grounding methods Ground of 100 Ω or less
Operating environment Ambient operating temperature 0 to 55°C
Ambient operating humidity 10 to 95% RH (with no icing or condensation)
Atmosphere Must be free from corrosive gases.
Ambient storage temperature -25 to 70°C (with no icing or condensation)
Altitude 2,000 m max.
Pollution degree Pollution degree 2 or less: Conforms to JIS B 3502 and IEC 61131-2.
Noise immunity Conforms to IEC 61000-4-4, 2 kV (power supply line)
Overvoltage category Category II: Conforms to JIS B 3502 and IEC 61131-2.
EMC immunity level Zone B
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 Conforms to IEC 60068-2-27, 147 m/s2, 3 times each in X, Y, and Z directions
Applicable standards * cULus: Listed (UL61010-2-201), ANSI/ISA 12.12.01, EU: EN 61131-2, NK, LR, RCM, KC: KC Registration

* Ask your OMRON representative for the most recent applicable standards for each model.

Function Specification

Supported: Functions that are used in target applications
-: Functions that are not used in target applications

Function Application Description
Weight measurement *1 Force measurement *2
I/O refreshing method setting *3 Supported. Supported. Sets Free-Run refreshing, synchronous I/O refreshing,*4 or task period prioritized refreshing*5 for the I/O refreshing*6 method.
Actual load calibration Supported. Supported. This is a user calibration function that is performed by placing an actual load on the load cell.
Equivalent input calibration Supported. Supported. This is a user calibration function that is performed by inputting the rated output, rated capacity, and zero balance values of the load cell.
Gravity acceleration correction Supported. - This function corrects errors in the gross weight values that occur due to the difference of gravity acceleration at each site when the site where the actual load calibration of the device is executed and the installation site are different.
Digital filtering Supported. Supported. This function uses the digital filter to remove noise components that are contained in input signals to suppress fluctuations of measurement values. You can use the digital low-pass filter and moving average filter.
Zero set/ zero reset Supported. Supported. The zero set function corrects the gross weight value/force measurement value to be the zero point within the set range at a desired time. The zero reset function resets the zero point correction that is performed with the zero set function.
Zero tracking Supported. - This function automatically corrects the zero point within the set range.
Zero point range over detection Supported. Supported. This function detects when the gross weight value/force measurement value exceeds the set zero point range.
Tare subtraction Supported. - This function subtracts the tare weight value from the gross weight value to acquire the net weight value. There are two types of this function: one-touch tare subtraction and digital tare subtraction.
One-touch tare subtraction Supported. - This function stores the gross weight value at the specified timing as the tare value and subtracts it from a given gross weight value to acquire the net weight value.
Digital tare subtraction Supported. - This function subtracts the preset digital tare value from the gross weight value to acquire the net weight value.
Stable detection Supported. - This function detects whether the gross weight value is stable.
Over range/under range detection Supported. Supported. This function detects when the input signal exceeds the input conversion range.
Sensor disconnection test Supported. Supported. This function tests if the cable that connects the Load Cell Input unit and load cell is disconnected. During the sensor disconnection test, you cannot measure the weight or force.
Input value refreshing stop Supported. Supported. This function stops refreshing the input value in a specified period.
Peak hold/ bottom hold - Supported. This function continues holding the peak value or the bottom value of the force measurement value in a specified period.
Data tracing Supported. Supported. This function records the values in REAL data in the buffer of the load cell input unit and exports the data to a CSV file. These values indicate the gross weight values/force measurement values before and after the digital filtering in a specified period.
Decimal point position setting Supported. Supported. This function sets the number of digits which is displayed after the decimal point for each DINT data.

*1. It is used to measure the weight in the unit of kg or t.
*2. It is used to measure the force in the unit of N or kN.
*3. Select with the Communications Coupler unit setting. Refer to the NX-series load cell input unit User’s Manual (W565) for details on the setting method.
*4. You can select this option only when the unit is used with an EtherCAT Coupler unit with EtherCAT communications in DC mode.
*5. You can select this option only when the unit is used with an EtherCAT Coupler unit NX-ECC203 with EtherCAT communications in DC mode.
*6. This is the data exchange with the Controller.

Individual Specifications

load cell input unit

NX-RS1201

unit name load cell input unit model NX-RS1201
Number of points 1 point External connection terminals Screwless clamping terminal block (16 terminals)
I/O refreshing method Free-Run refreshing, synchronous I/O refreshing, or task period prioritized refreshing
Indicators TS indicator 3538_sp_3_1 Input range -5.0 to 5.0 mV/V
Input conversion range -5.5 to 5.5 mV/V
Load cell excitation voltage 5 VDC ± 10%, Output current: 60 mA max.
Zero point adjustment range -5.0 to 5.0 mV/V
Gain point adjustment range -5.0 to 5.0 mV/V
Accuracy *1 Nonlinearity ±0.01% (full scale) *2
Zero drift ±0.1 μV/°C RTI
Gain drift ±10 ppm/°C
A/D converter resolution 24 bits
Warm-up period 30 minutes Conversion cycle 125 μs
Dimensions 12 (W) × 100 (H) × 71 (D) Isolation method Between the input and the NX bus: Power = Transformer, Signal = Digital isolator
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 No supply Current capacity of I/O power supply terminal Without I/O power supply terminals
NX unit power consumption • Connected to a CPU unit 2.05 W max.
• Connected to a Communications Coupler unit 1.70 W max. 		Current consumption from I/O power supply No consumption
Weight 70 g max.
Circuit layout 3538_sp_3_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
Diagram of the 6-wire connection between the unit and a load cell. 3538_sp_3_3
Diagram of the 4-wire connection between the unit and a load cell. 3538_sp_3_4

*1. Accuracy for when the load cell and the load cell input unit are connected with the 6-wire connection. *2. The value for when the Load Cell unit is used under the following conditions. Full scale: 0.0 to 5.0 mV/V or -5.0 to 0.0 mV/V Ambient temperature: 25°C Setting of digital filtering: Default

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 unit Corresponding versions *
model unit version CPU unit Sysmac Studio
NX-RS1201 Ver.1.0 Ver.1.13 or later Ver.1.17 or higher

* 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 unit Corresponding versions *
EtherCAT EtherNet/IP
model unit version Communications Coupler unit NJ/NX-series CPU units or NY-series Industrial PCs Sysmac Studio Communications Coupler unit Sysmac Studio
NX-RS1201 Ver.1.0 Ver.1.0 or later Ver.1.05 or later Ver.1.16 or higher Ver.1.0 or later Ver.1.16 or higher

* 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.