USER MANUAL LOAD CELL (Expansion)

Transcription

1 USER MANUAL LOAD CELL (Expansion)

2 Table of Content INTRODUCTION... 4 LOAD CELL... 4 PRODUCT SPECIFICATIONS... 4 PRINCIPLE OF A LOAD CELL... 4 GROSS WEIGHT... 4 NET WEIGHT... 4 SPAN... 4 WEIGHT MEASUREMENT... 5 A/D CONVERSION... 5 ACCURACY... 5 DIGITAL OUTPUTS... 5 STATUS FLAGS... 5 WIRING DIAGRAM... 6 ONE INPUT 4 WIRE LOAD CELL CONNECTION DIAGRAM... 6 ONE INPUT 6 WIRE LOAD CELL CONNECTION DIAGRAM... 6 ONE INPUT LOAD CELL PARALLEL WIRING DIAGRAM... 7 NPN TYPE OUTPUT WIRING... 8 PNP TYPE OUTPUT WIRING... 8 LOAD CELL CONFIGURATION... 9 CALIBRATION IN LOAD CELL ZERO CALIBRATION USER CALIBRATION MODE TWO-POINT CALIBRATION METHOD SETTING Renu Electronics Pvt. Ltd. 2

3 WEIGHT CONVERSION METHODS SAMPLING COUNT AVERAGE MOVING AVERAGE COMBINATION USE OF COUNT AVERAGE AND MOVING AVERAGE EXAMPLE EXAMPLE CONFIGURATION REGISTERS STATUS FLAG DETAILS FOR INPUT STATUS FLAG DETAILS FOR OUTPUT TAG ADDRESS TAG NAME STATUS VALUE REVISION HISTORY NOTES Renu Electronics Pvt. Ltd. 3

4 Introduction The FL series expansion products add analog capability to your PLC / SCADA. This model has 2 load cell inputs and 2 digital NPN transistor type outputs. This expansion model supports FL PLC series. Load Cell A load cell is also referred to as a load transducer. When a load is applied to a load cell it will convert the load into an electric signal and output the signal. Product Specifications Rated Power / Consumption Power Consumption 24VDC (-15% and +20%) / 4W (One 350Ω Load Cell) (Four 350Ω Load Cell) No. of Inputs 2 Type 4 Wire Load Cell (+Exc, -Exc, +Signal, -Signal, Shield) Min. Input Sensitivity 0.3µV/Count Input Range Selection 1mV/V, 2mV/V, 4mV/V Max. Input Signal 48mV Excitation Output Voltage 10VDC, +/-5% Excitation Output Current 140mA (up-to 4 units of 350Ω Load Cell can be connected in parallel) Isolation Isolation of 1KV between External Power Supply and Load Cell Inputs Principle of a Load Cell A load cell is a transducer that is used to create an electrical signal whose magnitude is directly proportional to the force being measured. The various load cell types include hydraulic, pneumatic, and strain gauge. A load cell module provides 24-bit resolution applicable to 4-wire or 6-wire load cells with various eigenvalues. Therefore, its response time can be adjusted according to users requirements. On this basis, the requirements of load application markets can be easily met. Tare weight is the weight of an empty vehicle or container. By subtracting it from the gross weight (laden weight), the weight of the goods carried (the net weight) may be determined. Gross Weight Gross weight is a term that is generally refers to the total weight of a product and its packaging. Net Weight Actual, computed or estimated weight of a good without its container and packaging. Net Weight = Gross Weight Tare Weight SPAN SPAN is the difference between the maximum operating capacity and zero live load of a weighing system. Renu Electronics Pvt. Ltd. 4

5 Weight Measurement Weight Conversion methods Weight type Tare Weight 0 to Weighing Format Grams Moving Average, Count Average, Sampling Process, Combination of Moving and Count Average Gross and Net A/D Conversion Conversion Method Resolution Conversion time Accuracy Gain Drift Zero Drift Sigma-Delta 24-bit 2msec 0.08% / input 0.04% / input 0.02% / input 0.2µV / 0 C Digital Outputs No. of Outputs 2 (Y0, Y1) Type NPN Transistor Max. Load Current Output Response Time OFF to ON : <100µsec ON to OFF : <100µsec Output Indication LEDs Status Flags Weight Overload Flag Weight Empty Flag (zero weight) Input Analog Value Exceeds ON at Overload ON at Zero Weight ON Above 48mVDC Renu Electronics Pvt. Ltd. 5

6 Wiring Diagram One Input 4 Wire Load Cell Connection Diagram One Input 6 Wire Load Cell Connection Diagram In 6 wire Load Cell connection: 1. Short Excitation+ and Sense+ 2. Short Excitation- and Sense- Renu Electronics Pvt. Ltd. 6

7 One Input Load Cell Parallel Wiring Diagram Renu Electronics Pvt. Ltd. 7

8 NPN Type Output Wiring PNP Type Output Wiring Renu Electronics Pvt. Ltd. 8

9 Load Cell Configuration 1. In IO Allocation select Expansion: 2. Click on Expansion following screen will appear: 3. In above screen double click on Slot1 following screen will appear: Renu Electronics Pvt. Ltd. 9

10 4. In above screen, select Model type as per our hardware: Renu Electronics Pvt. Ltd. 10

11 5. Following screen will appear after selecting model : 6. Following screen will appear after selecting Configure : Analog Input Range : As per Sensor Properties of Load Cell. Count _Average : 4 (this is starting value for count average). Moving Average : 2(this is starting value for moving average). Max Weight of Load Cell : As per selected load cell weight. Renu Electronics Pvt. Ltd. 11

12 Tare Weight : Give Tare Weight if required. Gross/ Net : Select the type of Weight. Set Point : Minimum Weight Value for getting Output. Output above Set Point: Normal Output : Manually operate Output. Output ON : After reaching Set Point Output will ON. Output OFF : After reaching Set Point Output will OFF. Weight Conversion Method : As per requirement select Weight Conversion method. [Note: Give all weight in grams] 7. After selecting all parameter select Confirm and Close, then following screen will appear. 8. In this window click on check box : Download Configuration Setting and then select OK. Renu Electronics Pvt. Ltd. 12

13 Calibration in Load Cell Calibration can be defined as a set of operations that compares the accuracy of a measuring instrument of any type (such as a load cell) against a recognized standard. The process of calibration may also include adjusting the measuring instrument to bring it in alignment with the standard. Zero Calibration Following steps are used for zero calibration: 1. Check pan is empty for Zero Calibration. 2. Add Tag in Data Window as below: 3. Enable Zero_Calibration_CH1 TAG. 4. Check Weight_Empty_Flag_CH1 is Enable. 5. Check Weight_Value_CH1 is having Zero value. [Note: Channel number may vary as per hardware connection] Renu Electronics Pvt. Ltd. 13

14 User Calibration Mode In this mode calibration is done by user by using Two-point calibration method. Two-point calibration method setting Select user setting to configure the settings for two-point calibration values. When two-point calibration processing is performed with automatic setting selected. When performing two-point calibration processing with user setting selected, set a value using a sequence program. 1. Set Slot01_Enter_User_Calibration_Mode_CH1 to TRUE. 2. Now put minimum weight on load cell, wait for 2 seconds and set Slot01_Minimum_Calibration_Point_Latch_CH1 to TRUE. 3. Set Slot01_Minimum_Calibration_Point_Latch_CH1 to FLASE. 4. Now put maximum weight on load cell, wait for 2 seconds and set Slot01_Maximum_Calibration_Point_Latch_CH1 to TRUE. 5. Set Slot01_Maximum_Calibration_Point_Latch_CH1 to FLASE. 6. Set Slot01_Save_Calibration to TRUE. 7. Set Slot01_Save_Calibration to FALSE and also set Slot01_Enter_User_Calibration_Mode_CH1 to FALSE. 8. Now set Slot01_Enable_Factory_Or_User_Calibration_CH1 to TRUE. (Always set this TAG to TRUE whenever User Calibration needed for using Load Cell). 9. Set the values of Slot01_Minimum_Point_CH1 and Slot01_Maximum_Point_CH1 in grams. 10. Now keep the load cell empty and perform the zero calibration. - Set Slot01_Zero_Calibration_CH1 to TRUE. - Set Slot01_Zero_Calibration_CH1 to FALSE. [Note: Following table shows User Calibration Tag list for reference. Channel number may vary as per hardware connection.] Renu Electronics Pvt. Ltd. 14

15 Weight conversion methods Weight conversion refers to the process to convert an analog signal (load cell output signal) from the outside of the programmable controller to Digital output value and Gross weight output value for storing into the buffer memory. The following methods are available for the conversion process: Sampling processing. Count average processing. Moving average processing. Combination use of count average and moving average. Sampling After the measurement, the resulting Digital output value and Gross weight output value are stored into the buffer memory. The update cycle of measured values (sampling cycle) is 2ms. Setting method Click on configure, following screen will appear : Renu Electronics Pvt. Ltd. 15

16 1. In Weight conversion select : Sampling processing. Count average The sampling processing is executed for a predefined number of times and the resulting data is averaged after excluding the maximum and minimum values. Then, the averaged values are stored into the buffer memory. The processing time is calculated as follows: Processing time = (Number of sampling 2) ms Setting method 1. In Weight conversion select : Count Average. Renu Electronics Pvt. Ltd. 16

17 1. When the Count Average Setting is set to 6 times = 6 2 = 12 The average value will be output every 12ms X : Time Y : Weight Moving Average Each time the data is sampled, the resulting Digital output value and Gross weight output value averaged over a predefined number of samples. Then, the averaged values are stored into the buffer memory. As the moving average processing is performed for each sample, the latest Digital output value and Gross weight output value can be obtained. Setting method 1. In Weight conversion select : Moving Average Renu Electronics Pvt. Ltd. 17

18 2. Set the value (the number of times) for "Moving average setting". E.g.: 6 times X : Time Y : Weight Combination use of Count average and Moving average The output values of the count average processing are moving average processed and stored into the buffer memory. Setting method 1. In Weight conversion select : Moving and Count Both Renu Electronics Pvt. Ltd. 18

19 2. Set corresponding values for "Count average setting" and "Moving average setting". When "Count average setting" is set to 6 times and "Moving average setting" is set to 2 times: X : Time Y : Weight Renu Electronics Pvt. Ltd. 19

20 Example1 (Gross or Net Weight) A sensor is having Maximum Weight capacity 200kg, Tare Weight is 10kg and Net Weight is 40kg. Suppose user want to display Gross weight of product follow below procedure: Gross Weight = Net Weight + Tare Weight = = 50kg Gross Weight Configuration : Sensor range Select Gross Weight Starting Value Starting Value 200kg 10kg [Note: Slot01_Gross_OR_Net_CH1 = 0(Gross Weight)] Renu Electronics Pvt. Ltd. 20

21 Net Weight Configuration: Select Net Weight [Note: Slot01_Gross_OR_Net_CH1 = 1(Net Weight)] Renu Electronics Pvt. Ltd. 21

22 Example2 (2 Point Calibration) A sensor is having Maximum Weight capacity 200kg. Suppose user want to calibrate sensor with User Calibration Mode, follow the steps below : Step1 : User need to select any 2 points in between sensor Maximum capacity. E.g. We select 1st point 50kg(Min Weight) and second point 150kg(Max Weight). Save calibration steps : 1. Enter_User_Calibration_Mode_CH1 make it True. 2. Place minimum Weight that is 50kg on pan and TRUE Minimum_Calibration_Point_CH1 Tag. [Note : Make Minimum_Calibration_Point_Latch_CH1 False again after completing this step] 3. Put Maximum Weight on pan that is 150kg and TRUE Maximum_Calibration_Point_CH1 Tag. [Note : Make Maximum point latch1 False again after completing this step] Renu Electronics Pvt. Ltd. 22

23 4. Enable Save_Calibration Tag to save calibration. Step 2 : Set Slot01_Save_Calibration and Slot01_Enter_User_Calibration_Mode_CH1 to FALSE. Before enabling User Calibration. Enable user calibration steps: 1. Enable factory or user calibration ch1 TAG. 2. Place value of Minimum point equivivalent to Percentage Weight of Maximum capacity of sensor. Maximum Weight: 200kg Minimum Weight: 50kg So, Minimum point channel1 value = Minimum weight value in Grams for weight 50 kg,put value in Minimum point channel1. Renu Electronics Pvt. Ltd. 23

24 3. So, Maximum point channel1 value = Maximum weight value in grams For 200 kg weight,put value in Maximum_Point_Channel1. 4. Perform zero calibration steps. Zero Calibration Following steps are used for zero calibration: 1. Check pan is empty for Zero Calibration. 2. Add Tag in Data Window as below: 3. Enable Zero_Calibration_CH1 TAG. 4. Check Weight_Empty_Flag_CH1 is Enable. 5. Check Weight_Value_CH1 is having Zero value. [Note: Channel number may vary as per hardware connection] Renu Electronics Pvt. Ltd. 24

25 Configuration registers Tag Address Tag Name Details MWxx00 / MWxx08 Slot01_Analog_Input_Range_Selection_CH1 / Load Cell Type Slot01_Analog_Input_Range_Selection_CH2 MWxx01 / MWxx09 Slot01_Gross_OR_Net_CH1 / Slot01_Gross_OR_Net_CH2 Weight Output FTWO format MWxx02 / MWxx10 Slot01_Set _Point_CH1 / Slot01_Set_Point_CH2 Set Point value for digital output operation MWxx04 / MWxx12 Slot01_Tare _Weight_CH1 / User defined tare weight value Slot01_Tare_Weight_CH2 MWxx08 / MWxx14 Slot01_Weight_Conversion_Method_CH1 / Weight Conversion Method Slot01_Weight_Conversion_Method_CH2 MWxx07 / MWxx15 Slot01_Digital_Output_Operating_Mode_CH1 / Digital Operating Mode Slot01_Digital_Output_Operting_Mode_CH2 MWxx16 / MWxx17 Slot01_Count_Average_setting_CH1 / Slot01_Count_Average_Setting_CH2 User Defined Count to get Average Value MWxx18 / MWxx19 Slot01_Moving_Average_Setting _CH1 / Slot01_ Moving_Average_Setting_CH2 User defined Count to get Average Value MWxx20 / MWxx22 Slot01_Maximum_Weight_of_Loadcell_CH1 / Maximum Weight of Load Cell Slot01_Maximum_Weight_of_Loadcell_CH2 Mxx384 / Mxx385 Slot01_Zero _Calibration_CH1 / Slot01_Zero _Calibration_CH2 To Start Zero Calibration [Note: xx determines Slot Number] Tag address Tag Name Tag type Tag Size(bytes) Tag Attribute Mxx386 Enter user calibration mode (CH 1) MW Bit RW Mxx387 Minimum calibration point latch (CH 1) MW Bit RW Mxx388 Maximum calibration point latch (CH 1) MW Bit RW Mxx390 Enable factory or user calibration (CH 1) MW Bit RW MWxx25 Minimum point (CH 1) MW 4 RW MWxx27 Maximum point (CH 1) MW 4 RW Mxx391 Enter user calibration mode (CH 2) MW Bit RW Mxx392 Minimum calibration point latch (CH 2) MW Bit RW Mxx393 Maximum calibration point latch (CH 2) MW Bit RW Mxx395 Enable factory or user calibration (CH 2) MW Bit RW MWxx29 Minimum point (CH 2) MW 4 RW MWxx31 Maximum point (CH 2) MW 4 RW Mxx389 Save calibration MW Bit RW Renu Electronics Pvt. Ltd. 25

26 Status Flag Details for Input Tag Address Tag Name Status Value Xxx001 / Xxx005 Xxx002 / Xxx008 Xxx003 / Xxx007 Xxx008 / Xxx009 Xxx010 / Xxx011 XWxx01 / XWxx03 Slot01_Weight_Overload_Flag _CH1 / Slot01_Weight_Overload_Flag_CH2 Slot01_Weight_Empty_Flag_CH1 / Slot01_ Weight_Empty_Flag _CH2 Slot01_Input_AnalogValue_Exceed_Flag _CH1 / Slot01_Input_Analog_Value_Exceed_Flag_ CH2 Slot01_Zero _Calibration_Done _CH1 / Slot01_ Zero _Calibration_Done _CH2 Slot01_Digital _Output_Status _CH1 / Slot01_ Digital _Output_Status _CH2 Slot01_ Weight _Value_CH1 / Slot01_ Weight _Value _CH2 When 1: Weight Overload When 1: Weight Empty When 1: Analog Value Exceeds Range When 1: Zero Calibration Done When 1: Output ON 0 to (Weight Value Output) Status Flag Details for Output Tag Address Tag Name Status Value Yxx000 Yxx001 Slot01_OutputCoil _00000 Slot01_OutputCoil_00001 When 1: Y0 Output ON When 1: Y1 Output ON [Note: xx determines Slot Number] Renu Electronics Pvt. Ltd. 26

27 Revision History Revision Description Date Prepared by Approved by 1.0 First Draft 25/10/2018 PM AR 1.1 Modified steps under User 3/12/2018 PM AR Calibration Mode 1.2 Minimum and Maximum 12/12/2018 YR AR weight type (from % to gram) and data type (word to dword) changes. 1.3 Modified Min Max weight in example and images 12/12/2018 YR AR Renu Electronics reserves the right to change or discontinue specifications and features without prior notice. Renu Electronics Pvt. Ltd. 27

28 NOTES Renu Electronics Pvt. Ltd. 28