US508MT Digital Flow Meter
US208MTUser Manual-V20240127The flow rate displayed is in litres per minute. The total flow displayed is in Litres. (By pressing SHIFT to shift the display)How to setProvide5-24V DCpower to light on,
- Model： US508MT
US508MT User Manual-V20240127
The flow rate displayed is in litres per minute. The total flow displayed is in Litres. (By pressing SHIFT to shift the display)
How to set
Provide 5-12V DC power to light on.
Open the back cover of the device
Press SET for 5 seconds to enter the menu or parameters
Then press SET to select the menu
Press + or - to increase or decrease the number, hold + or – to change the numbers quickly.
Parameters
1. 1.00500-K value, this setting value is 100 times the real K value
For example: the formula of the flow sensor is F=8Q, then real K=8, setting K is 800;
Range: 1-65535
Default value:500
2. 2.00500 – upper limit alarm value
=500L/Min means the alarm will go off when the flow rate is greater than the alarm value
Range: 1-65535
Default value:500
3. 3.001.00 – lower limit alarm value
=1.00 means the alarm will go off when the flow rate is lower than 1.0 litres/min
=0, function off
Range: 0.01-655.35
Default value:1.0
4. 4.00000: Total amount alarming value. When =0, Function off.
Range: 1-65535
Default value: 0, no display, no total volume alarm output.
5. 5.00000: Alarming time period. When =0, Function off.
Range: 1-65535
Default value: 0, always alarm after triggerred, when=3, alarm for 3 seconds and then off.
6. 6.00002: Decimal,
Range: 1-3
Default value: 2. the display number will show like 2.35(L/Min)
How to calibrate
Use K (constant) to calibrate the flow rate
Frequency = K x Flow rate
If K set on 10, and the flow rate is 4 lts/min
To calibrate to 8 lts/min, change K to 5 (10x4/8)
US508MT has RS485 Communication Function, The protocol is as following
Model: US508MT
Working Voltage: DC 5-12V
Introduction
This series of products follows the MODBUS protocol instructions. Available command codes are 0x03, 0x06, and 0x10. CRC check: low bit first, high bit last.
Example: Use the 03 instruction to read multiple registers
0x010x030x000x000x000x030x050xCB
(Continuously read the values of 3 registers from the 0x0000 register of device No. 0x0001)
To write to a single register use the 06 instruction
0x010x060x000x010x000x010x190xCA
(Write 0x0001 to the 0x0001 register of device No. 0x0001)
Writing to multiple registers uses 10 instructions
0x010x100x000x000x000x020x040x000x000x000x010x320x6F
(Write 0x0000 to the 0x0000 register of device No. 0x0001, and write 0x0001 to the 0x0001 register of device No. 0x0001)
Default Settings:
Baud rate: 9600 (decimal)
MODBUS device address: 1 (decimal)
Flowmeter constant K value: 500 (decimal)
To modify baud rate parameters
The default baud rate is 9600, and the reading is 2.
If you modify the baud rate, modify the parameters as follows. (If you enter a value other than the value in the table, the baud rate will be restored to 9600, but when reading, it will be displayed as the modified value is not 2)
Setting | Baud Rate |
0 | 2400 |
1 | 4800 |
2 | 9600 |
3 | 19200 |
Register Address | Register Function |
0x0000 | Baud rate |
0x0001 | Device address, can be modified to 0x0001-0x00F7 (decimal 1-247) |
0x0002 | Sensor pulse K factor, the value read and written is 100 times the actual value |
0x0003 | Permanent cumulative flow higher register, unit, L (maximum 65535) |
0x0004 | Permanent cumulative flow lower register, unit, L (maximum 65535) |
0x0005 | Permanent cumulative flow decimal, the reading is 100 times the actual value, unit, L |
0x0006 | Permanent accumulated flow pulse number(accumulated 1L to return to 0) |
0x0007 | Temporary accumulated flow higher register, unit, L (maximum 65535) |
0x0008 | Temporary accumulated flow lower register, unit, L (maximum 65535) |
0x0009 | Temporary cumulative flow decimal, the reading is 100 times the actual value, unit, L |
0x000A | Temporary accumulated flow pulse number (accumulated 1L to return to 0) |
0x000B | Real-time flow rate, unit: L/min, the reading is 100 times the actual value |
0x000C | Real-time(per second) pulse number unit Hz |
Note:
1. After the address, baud rate, K factor, and permanent cumulative flow are modified, the device needs to be restarted to take effect.
2. Please close the input pipeline before clearing the cumulative flow to prevent water from passing by again after clearing. The value changes after 60 seconds, and the program changes the value again so that the cumulative amount cannot be returned to zero.
3. Reset the temporary cumulative flow after power failure, and record the permanent cumulative flow every 60 seconds. (Flows must exceed 1 litre within 60 seconds to be recorded)
4. When the low bit of the register is full of 65535, it will enter 1 into the higher bit. Example: Assuming a flow sensor with a cumulative flow higher register is 1 and the cumulative flow lower register is 2; then the total flow is 65535 * 1 +2 = 65537L
5. The maximum storage value of each register is 65,535, and the maximum storage data of the permanent cumulative flow of each flow sensor is 65,535 * 65,535 +65,535 = 4,294,917,600 liters of water
6. During the reset operation, the registers for the permanent accumulated traffic need to be reset at the same time, that is, the registers 3/4/5/6 should be reset at the same time. Temporary cumulative traffic reset is also subject to this rule.