US318MT Digital Flow Meter-iSentrol Technology

US318MT User Manual-V20241120

The flow rate displayed is in litres per minute. The total flow displayed is in Litres. (By pressing SHIFT to shift the display between current flow rate and total volume)

How to set

Provide 5-12V DC power to light on. Default: 5V

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.

Double press + or- to change the numbers by 1000.

Parameters

1. 1.005.00-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 008.00;

Range: 1-65535

Default value:500

2. 2.00002: Decimal,

Range: 1-3

Default value: 2. the display number will show like 0002.35(L/Min)

3. 3.00000: 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.

4. 4.005.00 – upper limit alarm value

=55L/Min means the alarm will go off when the flow rate is greater than the alarm value

Range: 1-65535

Default value:500

5. 5.001.00 – 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

6. 6.00000: Total amount alarming value. When =0, Function off.

Range: 1-65535

Default value: 0, no display, no total volume alarm output.

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)

Three Display Models:

a. Default Model: display current flow rate when there is water passing through, display 0000.00 when water stops.

b. Press Shift button once, display total volume.

c. Press SHIFT button again, display current flow rate when there is water passing through, display total volume when water stops.

US318MT has RS485 Communication Function, The protocol is as following

Model: Mod 318MT

Working Voltage: DC 5-24V

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

0x010 x030 x000 x000 x000 x030 x050 xCB

(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

0x01 0x06 0x00 0x01 0x00 0x03 0x19 0xCA

(Write 0x0003 to the 0x0001 register of device No. 0x0001)

Writing to multiple registers uses 10 instructions

0x010 x100 x000 x000 x000 x020 x040 x000 x000 x000 x010 x320 x6F

(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
4	115200

Register Address	Register Function
0x0000	Baud rate
0x0001	Device address, can be modified to 0x0001-0x00F7 (decimal 1-247)
0x0002	Decimal(Default 2: 2 decimals of flow rate)
0x0003	Alarming time period default 0, when set to 3, alarming 3 seconds and stop
0x0004	Sensor pulse K factor, the value read and written is 100 times the actual value
0x0005	Permanent cumulative flow higher register, unit, L (maximum 65535)
0x0006	Permanent cumulative flow lower register, unit, L (maximum 65535)
0x0007	Permanent cumulative flow decimal, the reading is 100 times the actual value, unit, L
0x0008	Permanent accumulated flow pulse number(accumulated 1L to return to 0)
0x0009	Upper limit flow rate for alarming
0x000A	Lower limit flow rate for alarming
0x000B	Total Volume for alarming
0x000C	Temporary accumulated flow higher register, unit, L (maximum 65535)
0x000D	Temporary accumulated flow lower register, unit, L (maximum 65535)
0x000E	Temporary cumulative flow decimal, the reading is 100 times the actual value, unit, L
0x000F	Temporary accumulated flow pulse number (accumulated 1L to return to 0)
0x0010	Real-time flow rate, unit: L/min, the reading is 100 times the actual value
0x0011	Real-time(per second) pulse number unit Hz the reading is 100 times the actual value
0x0012	On/off alarm 255=on, other value=off

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.