LCM-2WT
1 Weighing module principle
When the metal material is subjected to tension, the metal material becomes thinner and the electrical impedance increases; conversely, when compressed, the metal resistance becomes smaller. Applying this method to make a strain gauge is called weighing module. This type of device converts the pressure in a physical phenomenon into electrical signal output, so it often used in the occasion of load, tension and pressure conversion.
2 Introduction
- Thanks for your purchasing WECON LCM-2WT expansion module, the maximum resolution is 24-bit, using 4 or 6 wires weighing sensor.It can adjust the response speed according to the customer's demand, and can easily meet the overall demand of the current load application market;
- To ensure proper installation and operation of this product, please read the user manual carefully before using this module, this manual is only for LCM-2WT;
- Using RS485(Modbus protocol) to read/write data from/to LCM-2WT.
Warning: disconnect the power supply before installing/removing the module or wiring the module to avoid contact or product damage.
2.1 Specification
| Item | Description |
| Channel | Double channel |
| A/D converter | 24 bitΔˉ∑ A/D |
| Resolution | 24bit (signed) |
| Speed | 7.5/10/25/50/60/150/300Hz available |
| Polarity | Unipolar and bipolar |
| Non-linearity | ≤0.01% full scale(25℃) |
| Zero drift | ≤0.2μV/℃ |
| Gain drift | ≤10ppm/℃ |
| Excitation current | 5V,load impedance≥200Ω |
| Sensor sensitivity | 1mV/V-15mV/V |
| Isolation | Transformer (power supply) and the optical coupler (signal) |
| Lamp | Power supply lamp (24V), communication lamp(COM) |
| Power supply | 24V±20% 2VA |
| Operating temperature | 0~60℃ |
| Storage temperature | -20~80℃ |
| Dimension | 90(L)x58(W)x80(H) mm |
2.2 Valid bits
For more details, refer to sampling frequency in Chapter 5, Section 5.2 of this manual.
3 Dimensions
3.1 Dimensions
①COM: communication indicator of communication board and acquisition board
② 24V: 24V indicator
③ WT: channel input/output indicator
WE: Channel calibration indicator
④ LINK: comm indicator of RS485
⑤ RS485 communication terminal
⑥ DC24V power supply
⑦ Extension module name
⑧ DIN rail mounting slot
⑨ DIN rail hook
⑩ Mounting holes (φ4.5)
| Name | Description | Indicator state | State |
| LINK indicator | RS485 comm. indicator | Blink | Normal |
| OFF | Comm.is abnormal or failed | ||
| ON | Software is running abnormally or hardware failure | ||
| COM indicator | Communication & acquisition board comm. indicator | Blink | Normal |
| OFF | Comm.is abnormal or failed | ||
| ON | Software is running abnormally or hardware failure | ||
| WT indicator | Channel input/output indicator | Blink | Analog input is over range |
| ON | Analog input is in range | ||
| OFF | Channel is closed | ||
| WE indicator | Channel calibration indicator | OFF | Successful calibration |
| ON | Calibration failed or not calibrated |
- Be sure to use the terminals that fit the dimensional requirements.
- Apply 0.5 to 0.8 N.m (5 to 8 kgf.cm) torque to tighten the terminals
3.2 Terminals
Table 3 ‑1
| Terminals | Instruction | Terminals | Instruction |
| 24V+ | Power supply+ | 24V- | Power supply- |
| GND | Ground | FG1 | CH1 sensor grounding |
| E1+ | CH1 power supply+ (5V) for sensor | E1- | CH1 power supply- (5V) for sensor in |
| S1+ | CH1 signal output+ of sensor | S1- | CH1 signal output- of sensor |
| F1+ | CH1 feedback+ of sensor | F1- | CH1 feedback- of sensor |
| E2+ | CH2 power supply+ (5V) for sensor | E2- | CH2 power supply- (5V) for sensor in |
| S2+ | CH2 signal output+ of sensor | S2- | CH2 signal output- of sensor |
| F2+ | CH2 feedback+ of sensor | F2- | CH2 feedback- of sensor |
| FG2 | CH2 sensor grounding |
4 Wiring
✎Note:
- The impedance of the weighing sensor is greater than 50 Ω
- The sensor with 4 wires requires E1+ connecting with F1+, E1 connecting with F1.
5 BFM instruction
5.1 BFM list
Table 5 ‑2
| BFM | Latched | Read/Write | Function | Default | Range | Description | |
| CH1 | CH2 | ||||||
| #0 | 0 | R | Model | 6050 | LCM-2WT model number | ||
| #1 | 0 | R | System version | 100 | Software & hardware version | ||
| #2 | #42 | 0 | R/W | Unipolar/Bipolar | 0 | 0-1 | 0: bipolar 1: unipolar |
| #3 | #43 | 0 | R/W | Sampling frequency | 1 | 0-9 | 0: 7.5 Hz; 1: 10 HZ; 2: 25 Hz; 3: 50 Hz; 4: 60 Hz; 5: 150 Hz; 6: 300 Hz; 7: 600 Hz; 8: 960 Hz; 9: 2400 Hz; 10: 10~4800hz |
| #4 | #44 | X | R | State code | 0 | - | Refer to chapter 5.2 |
| #5 | #45 | X | R | Error code | 0 | - | It is the data register for all error states, and each error status is displayed in the corresponding bit, possibly with multiple error states 0: No error; 1: Error; b0: Power supply error; b1: Hardware error; b2: CH1 conversion error; b4-b15: Reserved; #45: Reserved; |
| #6 | #46 | X | R/W | Tare weight | 0 | 0~1 | Use the current average value as the tare weight 0: Disable; 1: Enable, reset afterwards; Others: Reserved; |
| #7 | #47 | O | R/W | Gross/Net weight | 0 | - | Display gross weight or net weight as current weight 0: Gross weight; 1: Net weight; Others: Channel closed; |
| #8 | #48 | X | R/W | Calibrating weight | 0 | - | 0 by default。 0x0001: Return to 0 (ch1); 0x0002: Calibrating (ch1); Step1: Remove all load ; Step2: write 0x0001 to BFM #8; Step3: Add known weight; Step4: Write known weight to BFM#23 (#63); Step5: write 0x0002 to BFM #8; |
| #9 | #49 | X | R/W | Reset to default | 0 | 0-3 | #49:Reserve not use 1: Reset CH1; 2: Reset CH2; 3: Reset both channels; Others: Reserved; |
| #10 | #50 | 0 | R/W | Filtering mode | 0 | 0-1 | Need to recalibrate if changed |
| #11 | #51 | 0 | R/W | Filtering strength | 0 | 0-7 | Need to recalibrate if changed |
| #12 | #52 | 0 | R/W | Zero tracking intensity | 0 | 0-20000 | When the zero tracking function is turned on, the minimum interval between two clears, unit is 1 ms. |
| #13 | #53 | 0 | R/W | Zero tracking range | 0 | 0-100 | 0: Turn off zero tracking Other: Set the zero tracking range (absolute value) |
| #14 | #54 | 0 | R/W | Automatically zeroing | 0 | 0-4 | 0: Disable auto zeroing; 1: ±2%MAX; 2: ±5%MAX; 3: ±10%MAX; 4: ±20%MAX; |
| #15 | #55 | 0 | R | Sensor sensitivity setting | 4 | 0-5 | 0: <1V/V 1: <125mV/V 2: <62.5mV/V 3: <31.25V/V 4: <15.625mV/V 5: <7.812mV/V Note: Recalibration is required after setting. (The version need to be 13904 and above) |
| #16 | #56 | X | R | Average L | 0 | Signed int | Average weight (Low) |
| #17 | #57 | Average H | Average weight (High) | ||||
| #18 | #58 | 0 | R/W | Sliding average | 5 | 1-50 | Setting range:K1~K50; Default value: K12; When the set value exceeds the range, it is automatically changed to the critical value K1 or K50. |
| #19 | #59 | 0 | R/W | Tare weight L | 0 | The user can write or read the tare #7 by the instruction. Range: K-8388608~K8388607 | |
| #20 | #60 | Tare weight H | |||||
| #21 | #61 | 0 | R/W | Standstill checking times | 200 | 0-20000 | Stable inspection time, used in conjunction with the stable inspection range, unit: ms. |
| #22 | #62 | 0 | R/W | Checking range | 1 | 1-10000 | If the stability check range is set to 100 and the stability check time is set to 200ms, the current weight jump range is within 100 for 200ms, the value is considered stable, and other conditions are considered unstable. The stable flag is displayed in BFM#4. |
| #23 | #63 | 0 | R/W | Calibration weight value L | 1000 | Range: -8388608~8388607 Please refer to #8 | |
| #24 | #64 | 0 | Calibration weight value H | ||||
| #25 | #65 | 0 | R/W | Weight limit L | 32767 | Show error when exceeds Max. weight value Range: -8388608~8388607 | |
| #26 | #66 | 0 | R/W | Weight limit H | |||
| #27 | #67 | 0 | R/W | Zero upper limit L | 10 | -8388608~ 8388607 | The user can use the zero judgment function to know that the item has been removed from the weighing module. Bit of zero weight equals to 1 when all of load removed |
| #28 | #68 | 0 | R/W | Zero upper limit H | |||
| #29 | #69 | 0 | R/W | Zero lower limit L | -10 | -8388608~ 8388607 | |
| #30 | #70 | 0 | R/W | Zero lower limit H | |||
| #31 | #71 | X | R/W | Additional function options | 0 | 0~1 | 0: Default, disable additional functions; 1: Enable filter reset function. Other: Reserved |
| #32 | #72 | X | R/W | Additional function parameters | 0 | 0~100 | Enable filter reset function: 0: Default; 0~100: The number of sampling cycles to wait for the filter to restart. The values collected during the period are cumulatively averaged as the initial value of the filtering. |
| #33 | #73 | X | R | Digital value L | 0 | - | Digital value collected by the ADC |
| #34 | #74 | X | R | Digital value H | |||
| #35 | #75 | X | R | Reserved | Read only | ||
| #36 | #76 | X | R | Reserved | |||
| #37 | #77 | X | R | Reserved | |||
| #38 | #78 | X | R | Reserved | |||
| #39 | #79 | 0 | R/W | Sensor sensitivity setting | 2 | 0-32767 | Current sensor sensitivity in mV/V. If 10mV/V sensor is used, set to 10 (this setting is only related to the calibration flag) |
| #40 | #80 | 0 | R/W | Sensor feedback voltage L | 0 | - | Write: 0: not displayed 1: display current sensor feedback voltage in real time 2: Display zero voltage during calibration 3: Display the voltage when the weight is placed Read: Displays the high byte voltage value in uV. |
| #41 | #81 | 0 | R | Sensor feedback voltage H | 0 | Read: Displays the high byte voltage value in uV. | |
✎Note:
- 0: means latched address
- X: means non-latched address
- R: means readable
- W: means writable
BFM No. is the same as Modbus communication address.
5.2 Buffer (BFM) description
- BFM0: Module code
LCM-2WT code: 6050
- BFM1: module version
Module version (decimal) for example BFM1=100, means V1.0.0
- BFM2: Polarity
Bipolarity means that the signal passes through zero during the change process. Since the analog value converted to a digital value is a signed integer, the value corresponding to the bipolar signal will have a negative number.
- BFM3: Sampling frequency
The frequency at the module collects the signal. The lower the frequency, the more stable the value is, the higher the accuracy, but the lower the rate.
Table 5 ‑3
| Setting | Sample frequency (HZ) | Sample precision (Bits) | Setting | Sample frequency (HZ) | Sample precision (Bits) |
| 0 | 7.5 | 23.5 | 5 | 150 | 21.5 |
| 1 | 10 | 23.5 | 6 | 300 | 21 |
| 2 | 25 | 23 | 7 | 600 | 20.5 |
| 3 | 50 | 22 | 8 | 960 | 20 |
| 4 | 60 | 22 | 9 | 2400 | 17.5 |
- BFM4: State code
Table 5 ‑4
| Bit No | Description | |
| 1 | 0 | |
| Bit0 | CH1 zero weight (load free) | CH1 is not empty |
| Bit1 | CH2 zero weight (load free) | CH2 is not empty |
| Bit2 | CH1 is overload Note: The upper limit weight is set by #27, #28 | CH1is not overload |
| Bit3 | CH2 is overload Note: The upper limit weight is set by #27, #28 | CH2 is not overload |
| Bit4 | CH1 value is stable | CH1 value is not stable |
| Bit5 | CH2 value is stable | CH2 value is not stable |
| Bit6 | CH1 not calibrated | CH1 calibrated |
| Bit7 | CH2 not calibrated | CH2 calibrated |
Bit8 Bit9 | 00: no error 10: inputted weight is too large | 01: load free calibrated 11: not calibrated |
Bit10 Bit11 | 00: no error 10: inputted weight is too large | 01: load free calibrated 11: not calibrated |
| Bit12 | CH1 exceeds sensor range Note: determined by the sensor feedback voltage | CH1 is within the sensor range |
| Bit13 | CH2 exceeds sensor range Note: determined by the sensor feedback voltage | CH2 is within the sensor range |
- BFM5: Error code
Table 5 ‑5
| Bit No. | Value | Error | Bit No. | Value | Error |
| bit 0 | K1 (H0001) | Power failure | bit 1 | K1 (H0001) | Hardware failure |
| bit 2 | K2 (H0004) | CH1 conversion error | bit 3 | K8 (H0008) | CH2 conversion error |
| Others | Reserved | BFM#45 | Reserve not use | ||
| ✎Note: Save all error state of data registers, each error status is determined by the corresponding bit, there are May generate more than two states at same time, 0: no error, 1: error. | |||||
- BFM6(CH1) & BFM46(CH2): Tare setting
Select the current weight value (BFM16-17) as a tare (BFM19-20) weight value. Each channel occupies one bit, available when 1, reset to zero automatically.
Use CH1 as example
The current weight is 100, after setting tare weight:
If it displays gross weight (BFM7 = 0) currently, the tare weight (BFM19-20) will become 100, the current weight is still 100;
If it displays net weight (BFM7 = 1), the tare weight (BFM19-20) will be original value + current weight value, the current weight value becomes zero.
- BFM8: calibration steps: (described in CH1)
Step1: Do not put any weight on the load cell;
Step2: #8 value is written as 0x0001;
Step3: Add a standard weight to the load cell;
Step4: Write the weight of the weight on the current chassis to #23.
Step5: The #8 value is written as 0x0002.
- BFM11: filtering strength
The higher filter strength , the more stable and accurate weight value will be. but the delay will increase, and the sensitivity will decrease accordingly. It can be set according to need.
- BFM12: Zero tracking interval
BFM#12 is used together with BFM#13. When BFM#13 is not 0, BFM#12 indicates the time interval between the automatic weight clearing and the next automatic clearing to prevent continuous clearing.
Note: This function is generally used to correct the temperature drift of the sensor.
- BFM13: Zero tracking range
The cumulative range of zero tracking, if the total exceeds this range, the tracking will not continue.
Table 5 ‑6
| Settings | Description | Note |
| 0 | Zero tracking OFF | Default |
| 1-100 | When setting the zero tracking range (absolute value), the tracking must be performed when the value is stable and the current weight is within the zero tracking range. | If set to 10, the current weight is ±9, and the stable flag is 1, the current weight is cleared. |
| Note: when lower precision required, user could disable this function. | ||
For example:
The setting value is 100. After the zero point drifts from the 0 position to over ±100, the tracking will not continue. If it drifts back within ±100, the tracking is resumed.
- BFM15: Set the gain of the AD chip, which can be set according to the sensor range. After the BFM is set, it needs to be recalibrated.
| BFM15 | Voltage range | Sensor precision |
| 0 | ±5V | <1V/V |
| 1 | ±625mV | <125mV/V |
| 2 | ±312.5mV | <62.5mV/V |
| 3 | ±156.2mV | <31.25mV/V |
| 4 | ±78.125mV | <15.625mV/V |
| 5 | ±39.06mV | <7.812mV/V |
5.3 Function Instruction
1.Weight measurement
Normally, users can choose to measure the net weight or gross weight of an object. The net weight means the weight of the product itself, that is, the actual weight of the product without its external packaging.
The weight of the packaging is called the tare weight. The gross weight is the total weight, namely the net weight plus the tare weight.
- Tare weight: weight of the packaging
- Net weight: the weight of the product, excluding the packaging.
- Gross weight: the net weight plus the tare of the product.
- Gross weight= net weight + tare weight.
Example 1
A product weighs 10kg and the carton contains it weighs 0.2kg, then its gross weight is 10.2 kg (net weight=10kg, tare weight=0.2kg, gross weight=10.2kg)
Example 2
Use the measured value at CH1 as the net weight and disable CH2. If you know the weight of the packaging already, you can skip the step of reading the tare weight.
- Read the tare weight
Step 1: Write H0000 into BFM7.
Step 2: Place the packaging on the CH1 load cell.
Step 3: Write H0001 into BFM6 to take the weight of the packaging as the tare weight.
- Set BFM7 = H0001.
2.Standstill check
When an object is placed on the load cell to measure its weight, you can use the standstill check to know that the measured value has been stable.
- If the measured value shifts within the range for standstill check set up by the user, bit4 will be set to “1”.
- If the measured value shifts beyond the range for standstill check set up by the user, bit4 will be set to “0”. They will be set to “1” again when the range is returned to the set range.
Example
The measuring time is 10ms, the times of standstill check is 10, and the range for standstill check is 1,000. When the range for standstill check exceeds 1,000, the measured value will be regarded unstable, i.e. bit4 will be set to 0. When the measuring time is within 100ms (10 × 10ms) and the range returns to be within 1,000, bit4 will be set to 1 again. We recommend you check if the measured value is stable enough before operating it.
3.Zero detection
Users can use this function to know if the object has been removed from the load cell. If the bit4 is 1, and the bit0 and bit1 are 1 as well, the object has been removed from the load cell already, and you will be able to perform the next step of the control.
4.Filtering
The average value is a steady value obtained from the sum of the read values. However, due to unavoidable external factors, the read values may be an acute pulse, resulting in fierce changes in the average value. The filtering function thus exclude the read value that is an acute pulse from the sum-up and equalization, so the average value obtained will not be affected by the acute read value.
6 MODBUS settings
6.1 Com port communication configuration
| Com port comm. configuration | |
| Station No. | 1~32 (Adjust by DIP switch) |
| Baud rate | 9600~115200 (Adjust by DIP switch) |
| Stop bit | 1 |
| Data bit | 8 |
| parity | even |
6.2 Communication
The communication protocol is Modbus, support function codes 03 (read holding register), 06 (write single register), and 16 (write multiple registers).
1.0x03 function code description
Request (send from master)
| Slave address | 1 byte | Slave station No. |
| Function code | 1 byte | 0x03 |
| Start address | 2 bytes | 0x0000 to 0xFFFF |
| Register No. | 2 bytes | 1 to 125 |
| CRC | 2 bytes | CRC of all the above data |
Respond (reply from slave)
| Slave address | 1 byte | Slave station No. |
| Function code | 1 byte | 0x03 |
| Byte number | 1 byte | 2*N |
| Register value | N*2 bytes | |
| CRC | 2 bytes | CRC of all the above data |
✎Note: N is the number of register.
Error (reply from slave)
| Slave address | 1 byte | Slave station No. |
| Error code | 1 byte | 0x83 |
| Exception code | 1 byte | 01 (not support this function code) 02 (Address over range) |
| CRC | 2 bytes | CRC of all the above data |
Example: reading the value of the holding register (0x0000-0x0001) from slave (station No. 0x0f)
| Send from master | Reply from slave | ||
| Slave address | 0x0F | Slave address | 0x0F |
| Function code | 0x03 | Function code | 0x03 |
| Holding register high byte | 0x00 | Byte number | 0x04 |
| Holding register low byte | 0x00 | High byte of register 0 | 0x00 |
| High byte of read No. | 0x00 | low byte of register 0 | 0x0F |
| Low byte of read No. | 0x02 | High byte of register 1 | 0x00 |
| CRC low byte | 0xC5 | low byte of register 1 | 0x01 |
| CRC high byte | 0x25 | CRC low byte | 0xE4 |
| CRC high byte | 0x30 | ||
2.0x06 function code description
Request (send from master)
| Slave address | 1 byte | Slave station No. |
| Function code | 1 byte | 0x06 |
| Start address | 2 bytes | 0x0000 to 0xFFFF |
| Register value | 2 bytes | 0x0000 to 0xFFFF |
| CRC | 2 bytes | CRC of all the above data |
Reply (reply from slave)
| Slave address | 1 byte | Slave station No. |
| Function code | 1 byte | 0x06 |
| Register address | 2 bytes | 0x0000 to 0xFFFF |
| Register value | 2 bytes | 0x0000 to 0xFFFF |
| CRC | 2 bytes | CRC of all the above data |
Error (reply from slave)
| Slave address | 1 byte | Slave station No. |
| Error code | 1 byte | 0x86 |
| Exception code | 1 byte | 01 (not support this function code) 02 (Address over range) |
| CRC | 2 bytes | CRC of all the above data |
Example: writing 0x001 to address 0x00A from slave(station No. 0x0f)
| Send from master | Reply from slave | ||
| Slave address | 0x0F | Slave address | 0x0F |
| Function code | 0x06 | Function code | 0x06 |
| Holding register high byte | 0x00 | Register High byte | 0x00 |
| Holding register low byte | 0x0A | Register low byte | 0x0A |
| High byte of register value | 0x00 | High byte of register value | 0x00 |
| Low byte of register value | 0x01 | low byte of register value | 0x01 |
| CRC low byte | 0x69 | CRC low byte | 0x69 |
| CRC high byte | 0x26 | CRC high byte | 0x26 |
3.0X10 Function code description
Request (send from master)
| Slave address | 1 byte | Slave station No. |
| Function code | 2 bytes | 0x10 |
| Start address | 2 bytes | 0x0000 to 0xFFFF |
| Register No. | 2 bytes | 0x0001 to 0x0078 |
| Byte No. | 1 byte | 2*N |
| Register value | N*2 bytes | VALUE |
| CRC | 2 bytes | CRC of all the above data |
Reply (reply from slave)
| Slave address | 1 byte | Slave station No. |
| Function code | 1 byte | 0x01 |
| Starting address | 2 bytes | 0x0000 to 0xFFFF |
| Register No. | 2 bytes | 1 to 123 |
| CRC | 2 bytes | CRC of all the above data |
Error (reply from slave)
| Slave address | 1 byte | Slave station No. |
| Error code | 1 byte | 0x90 |
| Exception code | 1 byte | 01 (not support this function code) 02 (Address over range) |
| CRC | 2 bytes | CRC of all the above data |
Example: writing 0x001 and 0x002 to address 0x00A and 0x00B from slave (station No. 0x0f)
| Send from master | Reply from slave | ||
| Slave address | 0x0F | Slave address | 0x0F |
| Function code | 0x06 | Function code | 0x06 |
| Start address High byte | 0x00 | Start address High byte | 0x00 |
| Start address low byte | 0x0A | Start address low byte | 0x0A |
| High byte of register No. | 0x00 | High byte of register No. | 0x00 |
| low byte of register | 0x02 | low byte of register | 0x02 |
| Byte No. | 0x04 | CRC low byte | 0x29 |
| High byte of register 0 | 0x00 | CRC high byte | 0x27 |
| low byte of register 0 | 0x01 | ||
| High byte of register 1 | 0x00 | ||
| low byte of register 1 | 0x02 | ||
| CRC Low byte | 0x76 | ||
| CRC Low byte | 0xB3 | ||
6.3 Introduction of DIP switch
1.DIP switch introduction
Figure 6 ‑1 DIP switch
✎Note:
In practical use, the dial switch is ON (1) downward and OFF (0) upward. As shown in the figure, the status of the DIP switch is downward, all are ON.
2.DIP switch and station setting
In practical use, the # 1 to # 5 of the DIP switch is used for the selection of the module station number, and the relationship between the station number and the 1 # 5 dial number switch is shown in the following table:
| #1 DIP switch | #2 DIP switch | #3 DIP switch | #4 DIP switch | #5 DIP switch | Module station |
| 0 | 0 | 0 | 0 | 0 | 1 |
| 1 | 0 | 0 | 0 | 0 | 2 |
| 0 | 1 | 0 | 0 | 0 | 3 |
| 1 | 1 | 0 | 0 | 0 | 4 |
| 0 | 0 | 1 | 0 | 0 | 5 |
| 1 | 0 | 1 | 0 | 0 | 6 |
| 0 | 1 | 1 | 0 | 0 | 7 |
| 1 | 1 | 1 | 0 | 0 | 8 |
| 0 | 0 | 0 | 1 | 0 | 9 |
| 1 | 0 | 0 | 1 | 0 | 10 |
| 0 | 1 | 0 | 1 | 0 | 11 |
| 1 | 1 | 0 | 1 | 0 | 12 |
| 0 | 0 | 1 | 1 | 0 | 13 |
| 1 | 0 | 1 | 1 | 0 | 14 |
| 0 | 1 | 1 | 1 | 0 | 15 |
| 1 | 1 | 1 | 1 | 0 | 16 |
| 0 | 0 | 0 | 0 | 1 | 17 |
| 1 | 0 | 0 | 0 | 1 | 18 |
| 0 | 1 | 0 | 0 | 1 | 19 |
| 1 | 1 | 0 | 0 | 1 | 20 |
| 0 | 0 | 1 | 0 | 1 | 21 |
| 1 | 0 | 1 | 0 | 1 | 22 |
| 0 | 1 | 1 | 0 | 1 | 23 |
| 1 | 1 | 1 | 0 | 1 | 24 |
| 0 | 0 | 0 | 1 | 1 | 25 |
| 1 | 0 | 0 | 1 | 1 | 25 |
| 0 | 1 | 0 | 1 | 1 | 27 |
| 1 | 1 | 0 | 1 | 1 | 28 |
| 0 | 0 | 1 | 1 | 1 | 29 |
| 1 | 0 | 1 | 1 | 1 | 30 |
| 0 | 1 | 1 | 1 | 1 | 31 |
| 1 | 1 | 1 | 1 | 1 | 32 |
3.DIP switch and baud rate setting
In practical use, the #6 to #8 of the DIP switch are used for the selection of the baud rate, and the relationship between the baud rate and #6-# 8 DIP switch is shown in the following table:
Table 6 ‑7
| #6 DIP switch | #7 DIP switch | #8 DIP switch | Module baud rate |
| 0 | 0 | 0 | 115200 |
| 1 | 0 | 0 | 57600 |
| 0 | 1 | 0 | 38400 |
| 1 | 1 | 0 | 19200 |
| 0 | 0 | 1 | 9600 |
| 1 | 0 | 1 | Reserved for later expansion (Default: 115200) |
| 0 | 1 | 1 | Reserved for later expansion (Default: 115200) |
| 1 | 1 | 1 | Reserved for later expansion (Default: 115200) |
6.4 Note
LCM-2WT and LX3V-2WT differentiate in communication method, but the register functions are the same.
Table 6 ‑8
| Module | Max. accessible address (BFM address) |
| 2WT | 81 |
7 Example
7.1 Set the com port parameter
Set the station number as 2 and the baud rate as 115200 according to chapter 6.3.
PLC COM2 is set as MODBUS master, parameter is 115200, 1, 8 ,even.
7.2 The current state
Read the current state from BFM4, refer to the detail in chapter 5.2.
7.3 Calibration
The first step can also be used for manual zeroing.
The adjustment is to match the value of the module to the load cell.
- Step 1: Put nothing on the load cell
- Step 2: Write 0x001 to bfm8
- Step 3: Put a standard weight on the load cell
- Step 4: Write the value(D32)to BFM23
- Step 5: Write 0x0002 to BFM8
7.4 Tare and gross weight
- Step 1: Write K1 to BFM6 set the tare value
- Step 2: Write k1 to BFM7 (display net weight)
- Step 3: Write k0 to BFM7 (display gross weight)
7.5 Filter method setting
After the filter mode or filter strength is changed, it needs to be recalibrated.
- Step 1: Configure filter mode by writing value to BFM10
- Step 2: Set the filter strength (BFM11)
7.6 Zero point track
Zero tracking is used to reduce temperature drift.
The zero tracking strength is 0, which means that zero tracking is not turned on.
8 Diagnosis
8.1 Preliminary examination
- Check if the input/output wiring and/or extension cable are connected to the LCM-2WT module.
- Check if the number of special functions modules exceeds 8, and the total number of system I/O points cannot exceed 256 points.
- Ensure that the correct operating range is selected in the program.
- Check that there is no power overload in the 5V or 24V power supply.
- The LX3V main unit is at the RUN state.
8.2 Check error
If LCM-2WT does not work properly, please check the following items.
- Check the status of the power LED
ON: the extension cable is properly connected
Otherwise: Check the connection of the extension cable.
- Check external wiring
- Check the status of the "24V" LED (upper right corner of the LCM-2WT)
ON: The LCM-2WT is normal and the 24VDC power supply is normal.
Otherwise: The 24V DC power supply may be faulty. If the power supply is normal, the LCM-4LTC is faulty.
- Check the status of the “A/D” LED (upper right corner of LCM-2WT)
Lit: A/D conversion works normally.
Otherwise: Check buffer memory #5 (error status). If any of the bits (b0, b1 and b2) are in the ON state, which is why the A/D indicator is off.For detailed information, please refer to "Chapter 5" in this manual, specifically "5.2 Buffer Memory (BFM) Description," under "(6) BFM5: Error Codes."