Ultrasonic Flow meter for Fuel Gas Management UX

2020/03/27
Reference No.”TS-UX-001”
ver.1.1

Ultrasonic Flowmeter for Fuel Gas Management UX/UZ(Bore

15 and 25)
Modbus RTU Communication Specifications

Ultrasonic Flow meter for Fuel Gas Management UXTable of Contents
1

Overview .................................................................................................................................... 1

2

Prior to Use ................................................................................................................................ 2
2.1

Connection .......................................................................................................................... 2

2.2

Setting of Items Related to Communications (Flow

2.2.1

Setting of the Flow Meter's RTU Address ..................................................................... 2

2.2.2

Setting a Communication Bit Rate of the Flow Meter ................................................... 2

2.3
3

Meter) ............................................... 2

Setting Items Related to Communications (Higher-level Communication Device) .............. 2

Communication Specifications and Communication Timing ...................................................... 3
3.1

Communication Specifications ............................................................................................ 3

3.2

Communication Timing ........................................................................................................ 4

4

Message Frame Configuration ................................................................................................... 55

Function Code ............................................................................................................................ 6

6

7

5.1

[Function code 03] Reading of parameters and flow

meter information............................ 6

5.2[Function code 05] Integration value upper limit alarm clear ............................................... 7

5.3[Function code 06] Single parameter write .......................................................................... 8

5.4[Function code 10] Multiple parameter writes .................................................................... 10

5.5

Communication-related Item ............................................................................................. 12

Communication Error ............................................................................................................... 13
6.1

List of Communication Errors ............................................................................................ 13

6.2

Error Response ................................................................................................................. 13

6.3

Processing of Invalid Data ................................................................................................. 14

Data Specifications .................................................................................................................. 15
7.1

Address and Data .............................................................................................................. 15

7.2

List of Data ........................................................................................................................ 16

7.2.1

Various Types of Parameters ..................................................................................... 16

7.2.2

Details of Various Types of Parameters ..................................................................... 18

7.2.3

Flow

meter information, Clearing ............................................................................. 22

8

Factory Default Settings List of Set Values .............................................................................. 25

9Calculation of Error Check Code (CRC-16) ............................................................................. 26
9.1

Overview ............................................................................................................................ 26

9.2

Calculation Procedure ....................................................................................................... 26

Ultrasonic Flow meter for Fuel Gas Management UX

1 Overview
This communication specifications applies to "External power supply type (24VDC)" and "External
power supply type (100VAC)" of the Ultrasonic Flow Meter UX/UZ for fuel gas management.
Since this document only describes the communication procedures, refer to the operation manual of
the ultrasonic flow meter for fuel gas management (hereinafter referred to as "the flow meter”) for
instructions of operations, etc., other than communication,
The flow meter has the communication interface which equips the asynchronous serial bus interface
conforming to EIA-485. This interface enables to connect up to 31 flow meters to build a networked
system.
Modbus RTU Protocol is used as the communication protocol, so that measurement data and internal
information of each flow meter can be acquired by sending commands to each flow meter.

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Ultrasonic Flow meter for Fuel Gas Management UX

2 Prior to Use
2.1 Connection
With reference to the operation manual of the flow meter, connect it to the upper-levelcommunication device.

2.2 Setting of Items Related to Communications (FlowMeter)For the setting procedures of 2.2.1 through 2.2.4, refer to “Operation manual 8-1. Details of
setting items”.

2.2.1 Setting of the Flow Meter's RTU Address
Set the RTU address with Item No. F14, using the setting buttons on the display portion of
the flow meter. When connecting multiple flowmeters, be sure to use a unique RTU addressfor each of them.
Available addresses: 001 to 247* "000" cannot be used.

2.2.2 Setting a Communication Bit Rate of the Flow Meter
Select a communication bit rate with Item No. F13, using the setting buttons on the display
portion of the flow meter.

2.3 Setting Items Related to Communications (Higher-level Communication
Device)Match its communication bit rate with the setting of the flow meter.
* Set the data length to “8 bits", stop bit to “1 bit", and parity to “None.”-2-

Ultrasonic Flow meter for Fuel Gas Management UX

3 Communication Specifications and Communication Timing
3.1 Communication Specifications
Interface

Conforming to EIA-485

Communication method

Half-duplex system

Synchronization method

Asynchronous

Maximum number ofconnectable flow meters

Up to 30 flow meters

ProtocolModbus RTU

Communication speed[bps]

Selectable according to parameter setting※
4800, 9600

Data length [bit]8

Stop bit length[bit]1

Parity bit

None

Sending/Reception Buffer
size [byte]

100*The factory defaults are 9600bps.

Refer to the next section for the communication timing.

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Ultrasonic Flow meter for Fuel Gas Management UX

3.2 Communication Timing
The response time, standby time, and communication interval vary depending on the baud rate andcontents of a query from the higher-level communication device. Thus, refer to the table below<Response Time and Standby Time> and the figure below <Communication Timing Diagram>.
<Response Time and Standby Time>
Maximum response time① - Writing various types of parameters
[ms]
min
max
Remarks
100
400
If you set an item
300
800
If you set all items- Reading out various types of parameters, reading out flow meter
information, and clearing an integration value upper limit alarm
min
max
40
200
Maximum standby timeafter response from theown machine ② [ms]Maximum standby timeafter response from othermachine ③ [ms]Minimum communicationinterval

100

100
Query maximum time + Response time ① (Maximum value) +Maximum response time+ Maximum standby time (② or ③)<Communication Timing Diagram>【接続機器が１台の場合】[Case
where one device is connected]

Higher-level
上位通信機器
communication
deviceQuery
to flow meter
流量計AへのクエリAQuery
to flow meter
流量計Aへのクエリ
A

Flow 流量計A
meter A

Response to a higher-level

上位通信機器へのレスポンス
communication device
①

②

[Case
where more than one device is connected]【接続機器が複数の場合】Higher-level
上位通信機器
communication
device

流量計Aへのクエリ
Query
to flow meter
A

流量計Bへのクエリ
Query
to flow meter
A

Flow 流量計A
meter A

Response to a higher-level

上位通信機器へのレスポンス
communication device①③
Response to a higher-level
上位通信機器へのレスポンス

Flow 流量計B
meter B

communication device①

Message frame on
通信ライン上のthe communication
メッセージフレームline

流量計Aへのクエリ
Query
to flow meter
A

Response to a higher-level

上位通信機器へのレスポンス
communication device

流量計Bへのクエリ
Query
to flow meter
B

Response to a higher-level

上位通信機器へのレスポンス
communication device(1): Prepare to receive a response within the above-described time (the minimum value of ①) after
sending a query to the flow meter.
(2): Prepare time-out time to be longer than the above-described time (the maximum value of ①) after
sending a query to the flow meter.
(3): In case the flow meter is only the one connected to the master communication device, after
receiving a response from the flow meter, send the next query to the same flow meter after theabove-described time (②) passes.
(4): In case multiple meters are connected to the master communication device, after receiving a
response from any of them, send the next query after the above-described time (③) passes.
<Notes on programming>(1): Provide some margins for the times mentioned above for safety when programing the mastercommunication device.
(2): If a response from the flow meter cannot be received correctly after the master communication
device has sent a query, it is recommended to resend the query.

-4-Ultrasonic Flow meter for Fuel Gas Management UX

4 Message Frame Configuration
Start

RTU
address

Function
code

Data

Error check
code

End

Silentinterval※

1 byte1 byten bytes

2 bytes

Silentinterval** Silent communication time for 3.5 characters or more
<RTU address>“1” - “247” (01H - F7H) can be set for the flow meter.
The default is "1” (01H).
When a message from the master communication device is received, only the flow meter with thematching RTU address returns a response.
* Broadcast communication is not supported.
<Function code>
Each code specifies a function that the flow
The following function codes are available.

meter is commanded to perform.

Code (hex)Function

03

Read out a parameter or flow

meter information.

05

Clear the integration value upper limit alarm.

06

Writing of a single parameter10

Writing of multiple parameters<Data>
Data used to perform a function code. Configuration of this data section varies depending on thefunction code. Refer to “7. Data Specifications” for details.
<Error check code>
This code is intended to detect an error (bit change) in a message in the signal transmission process.
The checking method is based on the CRC method.
For details, refer to "9 Calculation of Error Check Code(CRC-16)”.
When the flow meter receives a message, it calculates a CRC value based on the received message,
and compares it with the sent CRC value.
If the two values do not match, the flowmeter determines that an error has occurred.
In the case of a message to be transmitted by the flowmeter, the flowmeter calculates a CRC value
based on the message to be transmitted, and transmits the message with the CRC value added to theend of the message.

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Ultrasonic Flow meter for Fuel Gas Management UX

5 Function Code
5.1 [Function code 03] Reading of parameters and flow

meter information

The function code 03H reads parameters, and flow meter information.
The function code and data portions, which are described in "4 Message Frame Configuration,”
are shown below.
<Query configuration>
Function code

03H

Start address
Data(Upper)(Lower)Number of(Upper)registers(Lower)Function code:
03H
Start address:
Register address (0100H to 0119H) and (0200H to 020EH)
Number of registers: Number of data to be read out (0001H to 001AH)
Note that the maximum number of reading data depends on register
addresses.
<Response configuration>
Function code

03H

Number of

Arbitrarydata bytes(Upper)Data 1
Data(Lower)(Upper)Data 2(Lower):Data N(Upper)(Lower)Function code:
03H
Number of data bytes: Number of bytes in response data
Data:
Read out data
Example) A case where [Address 0101H] Output pulse constant (0001H：10L/P,) and [Address
0102H] Alarm output contact state (0000H：normal open) are read out.
<Query> (hex value)
Start

Silent interval

RTU address

01

Function code03
(Upper)01(Lower)01

Number of(Upper)00

registers(Lower)02(Lower)(CRC)(Upper)(CRC)

Start address
Data

Error check code
End

Silent interval-6-Ultrasonic Flow meter for Fuel Gas Management UX<Response> (hex value)
Start

Silent interval

RTU address

01

Function Code03

Number of data bytes

Data

04

Data 1(Upper)00(Data of address 010)

(Lower)01

Data 2(Upper)00(Data of address 0102)(Lower)00(Lower)（CRC）(Upper)（CRC）

Error check code
End

Silent interval

5.2 [Function code 05] Integration value upper limit alarm clear
Function code 05H is intended for a command to clear an integration value upper limit alarm of theflow meter.
An alarm state occurs when an integration value per hour exceeds a set upper limit.
The function code and data portions, which are described in "4 Message Frame Configuration,” areshown below.
<Query configuration>
Function code
Start address
Data
Changed data

05H
03H
00H
00H
00H

Function code: 05H
Start address: 0300H (Fixed)
Changed data: 0000H (Fixed)<Response configuration>
Function code
Start address
Data
Changed data

05H
03H
00H
00H
00H

Function code: 05H
Start address: 0300H (Fixed)
Changed data: 000H (Fixed)-7-Ultrasonic Flow meter for Fuel Gas Management UX

5.3 [Function code 06] Single parameter write
Function code：06H is intended to make a change (perform a write) to contents of a parameter.
Shown below are parts of the function code and the data in “4 Message Frame Configuration”.
<Query configuration>
Function code
Start address
Data
Changed data

06H
(Upper)(Lower)(Upper)(Lower)Function code: 06H
Start address: Register address（0100H to 0119H）
Changed data: Arbitrary (For the range of changed data that may be set, refer to “7.2.1 Various
Types of Parameters).

<Response configuration>
Function code
Start address
Data
Changed data

06H
(Upper)(Lower)(Upper)(Lower)Function code: 06H
Start address: Same as the start address in a query
Changed data: Same as the changed data in a query

Example) A case where [Address 0100H] Conversion reference temperature is changed to 35℃(0x0023).
<Query> (hex value)
Start

Silent interval

RTU address

01

Function code

06

Start address
Data
Changed data

Error check code
End

(Upper)01(Lower)00(Upper)00(Lower)23(Lower)(CRC)(Upper)(CRC)
Silent interval-8-Ultrasonic Flow meter for Fuel Gas Management UX<Response> (hex value)
Start

Silent interval

RTU Address

01

Function code
Start address
Data
Changed data

Error check code
End

06
(Upper)01(Lower)00(Upper)00(Lower)23(Lower)(CRC)(Upper)(CRC)
Silent interval-9-Ultrasonic Flow meter for Fuel Gas Management UX

5.4 [Function code 10] Multiple parameter writes
Function code: 10H is an intended to change (write) contents of a plurality of consecutive
parameters.
Shown below are parts of the function code and data in “4 Message Frame Configuration”.
<Query configuration>
Function code

10H

Start address(Lower)Number of(Upper)registers(Lower)Number of

Arbitrarydata bytes
Data(Upper)(Upper)Data 1(Lower)(Upper)Data 2(Lower)：Data N(Upper)(Lower)Function code:
10H
Start address:
Register address (0100H to 0119H)
Number of registers: Number of data to be written (0001H to 001AH)
Number of data bytes: Number of bytes of data to be written
Changed data:
Arbitrary (For the range of changed data that may be set, refer to “7.2.1
Various Types of Parameters).
<Response configuration>
Function code
Start address
Data

10H
(Upper)(Lower)Number of(Upper)registers(Lower)Function code:
Start address:
Number of registers:

10H
Same as the start address in the query
Same as the number of registers in the query-10-Ultrasonic Flow meter for Fuel Gas Management UX
Example) A case of changing [Address 010FH] Actual flow conversion select to Yes (0x0001)
and changing [Address 0110H] Used gas pressure set value to 50kPa (1388H)/<Query> (hex value)
Start

Silent interval

RTU address

01

Function code10
(Upper)01(Lower)0F

Number of(Upper)00

registers(Lower)

02

Start address

Number ofdata bytes
Data

Arbitrary

Data 1(Upper)(Actual flow
conversion

04
00
01

(Lower)select)Data 2(Upper)(Used gaspressure set

13
88(Lower)value)
Error check code

(Lower)(CRC)(Upper)

(CRC)

End

Silent interval<Response> (hex value)
Start

Silent interval

RTU address

01

Function code10
(Upper)01(Lower)0F

Number of(Upper)00

registers(Lower)02(Lower)(CRC)(Upper)(CRC)

Start address
Data

Error check code
End

Silent interval-11-Ultrasonic Flow meter for Fuel Gas Management UX

5.5 Communication-related Item
When a single write or a multiple write to a item / items related to the communications (RTU
address, communication bit rate) is performed, the flow meter responds thereto with parameters
before the change has been made. For subsequent communications, the flowmeter operates withthe changed set value.

Example 1）A case of changing the RTU address of the flow

meter from 01 to 02 (hex value)

Query

Response

Silent interval

Silent interval

RTU address

0101

Function code

06

06

(Upper)01

01(Lower)0E

0E(Upper)00

00(Lower)02

02(Lower)

(CRC)

(CRC)

Start

Start address
Data
Changed data

Error check code

(Upper)

End

(CRC)

(CRC)

Silent interval

Silent interval

Returning a
response with 01H

Subsequently, theflow meter
operates with the
RTU address = 02

Example 2）A Case of changing the communication bit rate from 9600bps to 4800bps (hex value)
Query

Response

Silent interval

Silent interval

RTU address

0101

Function code1010(Upper)01

01(Lower)

0D

0D

Subsequently, the flow

Number of(Upper)00

00

meter operates at 4800bps

registers(Lower)

01

01

Start

Start address

Data

Number of data bytes

02

Data 1(Upper)00(Lower)01(Lower)(CRC)(Communication bit
rate)

Error check code
End

(Upper)

(CRC)

(CRC)

(CRC)

Silent interval

Silent interval-12-Returning a response at
9600bps

Ultrasonic Flow meter for Fuel Gas Management UX

6 Communication Error
6.1 List of Communication Errors
Communication errors are defined as listed in the table below.
Error code

Error item

01H

Illegal function

02H

Invalid data address

Error description
A function code other than 03H, 05H, 06H, and 10H.
No existing address
A specified internal address exceeding buffer size

03H

Invalid data

A data value being out of range

None (NoAny communication

Framing error, overrun error, parity error, CRC check

response)

error other thanerror

those listed above

6.2 Error Response
Listed below are parts of the function code and data in “4 Message Frame Configuration”.
In the case of an error response, the function code is an error function code. The error function
code is a code to the highest-order bit of which 1 is set.
Error Function code
FunctionError function

code

code

(hex)

(hex)

03

83

05

85

06

86

10

90

<Response configuration>
Error function code

Refer to the above table.

Data

Any of 01H, 02H, and 03HError code

Example) If you set 0006H for the gas species select:
You receive a response with the error code 03H for the invalid data, because the set data 0006H is avalue out of the range.
<Query> (hex value)
Start

Silent interval

RTU address

01

Function code
Start address
Data
Changed data

Error check code
End

06
(Upper)01(Lower)16(Upper)00(Lower)06(Lower)(CRC)(Upper)(CRC)
Silent interval-13-Ultrasonic Flow meter for Fuel Gas Management UX<Response> (hex value)
Start

Silent interval

RTU address

01

Error function code86

Set 1 to the highest-order bit

Data

03

of 06H

Error check code

Error Code
(Lower)(CRC)(Upper)

(CRC)

End

Silent interval

6.3 Processing of Invalid Data
If invalid data is detected in a single write, no write is performed.
If invalid data is detected in certain data in a multiple write, no values after the invalid data is detected
are set. However, values before the invalid data is detected are set.
For example, if you write [Addresses 0100H to 0102H] multiple times:
Example 1）
Conversion reference temperature: 0014H (20°C Normal data)
Output pulse constant:
0005H (Invalid data)
Alarm output contact state:
0000H (Normal open Normal data)
As shown above, when the second data of the three pieces of set data is the invalid data, the first
conversion reference temperature is set. However, because the second output pulse constant is theinvalid data, the output pulse constant and the alarm output contact state are not set.
A response with the error code 03H for invalid data is returned.
Example 2）
Conversion reference temperature: 003FH (63°C Invalid data)
Output pulse constant:
0001H (10L/P Normal data)
Alarm output contact state:
0000H (Normal open Normal data)
As shown above, when the first data of the three setting data is the invalid data, neither of the three
data is set.The response returned is the error code 03H for invalid data.

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Ultrasonic Flow meter for Fuel Gas Management UX

7 Data Specifications
7.1 Address and Data
Data is arranged as shown below:
Address
0000H
toFor system

00FFH
0100H
Various types of parameters fortothe flow meter

0116H
0117H
to

For system

01FFH
0200H
to

Flow meter information

020AH
020BH
to

For system

02FFH

0300H

Clear command

0301H
to

For system

FFFFH*Use of the area for system is not allowed.

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Ultrasonic Flow meter for Fuel Gas Management UX

7.2 List of Data
7.2.1 Various Types of Parameters
You can set various types of parameters and acquire internal information. Therefore, you
can use the following function codes.
Code(hex)

Function

03

Read out a parameter.

06

Single write of aparameter

10

A multiple write of aparameter

Function
code
(hex)

Address
(hex)

0100

0101

Output pulse constant

0102

Alarm output contact state

0103
0104

06

0105
0106

10

Parameter

Conversion reference
temperature※1

0107
0108
0109
010A
010B

Various types of parametersof flow meters

03

Area
Name

Alarm output upper limit (Upper 2
bytes)
Alarm output upper limit (Lower 2
bytes)
Alarm output lower limit (Upper 2
bytes)
Alarm output lower limit (Lower 2
bytes)
Alarm output hysteresis width(Upper 2 bytes)
Alarm output hysteresis width(Lower 2 bytes)
Instantaneous flow moving
average times
Analog output full-scale flow rate
(Upper 2 bytes)
Analog output full-scale flow rate
(Lower 2 bytes)

010C

Analog output switching

010D

Communication bit rate

010E

RTU Address

010F

Flow rate conversion select*1

0110

Used gas pressure set value（gage）*2-16-

Set Value(Range hex)
0xFFF6 to 0x003C (Set a
complement.)(-10 to +60°C, set a 1x
value.)
0x0001 : 10L/P
0x0002 : 100L/P
0x0003 : 1000L/P
0x0004 : 10000L/P
0x0000 : Normal open
0x0001 : Normal close
0x00000000 to
0x0001869F(0.0 to +9999.9 m3/h, set a
10x value.)
0x00000000 to
0x0001869F(0.0 to +9999.9 m3/, set a
10x value.)
0x00000000 to
0x0001869F(0.0 to +9999.9 m3/h, set a
10x value.)
0x0001 to 0x0010(1 to 16[times])
0x00000000 to
0x0001869F(0.0 to +9999.9 m3/h, set a
10x value.)
0x0000 : Instantaneous
flow rate
0x0001 : Temperature
0x0002 : Pressure*1
0x0000 : 4800bps
0x0001 : 9600bps
0x0001 to 0x00F7(1 to 247)0x0000 : Not select (Actual
flow rate)
0x0001 : Select (Normal or
standard flow rate)
UX :0x0000 to 0x2710(0.00 to 100.00kPa, set a
100x value.)
UZ : 0x0000 to 0xC350(0.00 to 500.00kPa, set a
100x value.)Ultrasonic Flow meter for Fuel Gas Management UX
Function
code
(hex)

Address
(hex)

Area
Name

Parameter

Test mode time select

0111
03

Conversion reference pressure

0112

06
0114

0115
10
0116

Various types of parameters of flow meters

0113(gage)*

1

Integration value upper limit
alarm threshold(Upper 2 bytes)

Integration value upper limit
alarm threshold

Set Value(Range hex)
0000 : 3 minutes
0001 : 60 minutes
0002 : No limit
0x0000 to 0x03E8(0.00 to 10.00kPa, set a
100x value.)

0x00000000 to
0x000F423F(0000.00 to 9999.99 m3, set
a 100x value.)(Lower 2 bytes)

Alarm output selectGas species select-17-0x0000 : Flow rate upperand lower limit alarm
0x0001 : Integration value
upper limit alarm
0x0000 : 13A
0x0001 : Propane
0x0002 : Butane
0x0003 : Nitrogen
0x0004 : Air

Ultrasonic Flow meter for Fuel Gas Management UX

7.2.2 Details of Various Types of Parameters
1. [Address 0100H] Conversion reference temperatureThis item is to set a designated temperature [°C] that is used as a reference at the time of
conversion.
Setting is possible in the increment of 1°C, in the range of -10 to +60°C (FFF6H to 003CH).
To set the parameter, treat it as date with sign (+/-).

2. [Address 0101H] Output Pulse Constant
The parameter is to select weight “10L/P(0001H)”, ”100L/P(0002H)”, ”1000L/P(0003H)”, or“10000L/P(0004H)”.

3. [Address 0102H] Alarm output contact state
The parameter is to select “Normal open (0000H)” or”Normal close (0001H)”.
If you use a battery-driven pulse receiver, use Normal open.

4. [Address 0103H, 0104H] Alarm output upper limit
The parameter is to set an alarm output upper limit of the flow rate upper/lower limit alarm.
When you set this parameter, set a 10x value.
With 4byte data, setting is possible in the range of 10x values 00000000H to 0001869FH of
0 to 9999.9[m3/h].
An address is assigned to each of upper 2 bytes and lower 2 bytes.
[Address 0103H]: Alarm output upper limit (Upper)[Address 0104H]: Alarm output upper limit (Lower)
You can set upper level only or lower level only. Note, however, that a settable range isdetermined as the 4byte data.
Example) Upper 0000H, Lower 9876H→Alarm output upper
limit=00009876H→3903.0[m3/h]
If you try to change only the upper bytes to 0001H, setting is not allowed due to out ofsetting range.
Alarm output upper limit=00019876H→10456.6[m3/h]>9999.9[m3/h]
5. [Address 0105H, 0106H] Alarm output lower limit
The parameter is to set an alarm output lower limit of the flow rate upper/lower limit alarm.
Details are similar to [Address 0103H, 0104H] Alarm output upper limit.

6. [Address 0107H, 0108H] Alarm output hysteresis width
For a flow rate value set in the alarm output upper limit and lower limit, set an alarm output
hysteresis width as a flow rate width for stopping the alarm.
Details are similar to [Address 0103H, 0104H] Alarm output upper limit.

-18-Ultrasonic Flow meter for Fuel Gas Management UX
7. [Address 0109H] Instantaneous flow moving average times
The parameter is to refer to a moving average times of instantaneous flow measurement
results.
You can select once (No average)(0x0001) to 16 times (0x0010).
The instantaneous flow rate measured most recently is displayed/outputted as an averagevalue of the selected moving average times.

8. [Address 010AH, 010BH] Analog output full-scale flow rate
The parameter is to set a full-scale flow rate value of analog output.
Setting is enabled when you select “Instantaneous flow rate”for [Address 010CH] Analog
output switching.
It is FS flow rate corresponding to setting of [Address 010FH] Actual flow conversion
select.
When you set this parameter, set a 10x value.
Details are similar to [Address 0103H, 0104H] Alarm output upper limit.

9. [Address 010CH] Analog output switching
The item is to select the function assignment of analog output from “Flow rate (0000H)”,“Temperature (0001H)”, or “Pressure (0002H)”.
When you select the instantaneous flow, set a relative value of the instantaneous flowrate selected for [Address 010FH] Actual flow conversion select.

[Address
010CH]
Analog output
switching

Instantaneous Flow rate 0: Currents 4 [mA]flow rate
Flow rate FS*: Currents 20 [mA]
Temperature

Current value corresponding totemperature [mA]

*FS: Set value of [Address 010AH, 010BH] Analog output full-scale flow rate

10. [Address 010DH] Communication bit rate
The parameter is to set the communication bit rate “4800bps (0000H)””9600bps(0001H)”.

11. [Address 010EH] RTU Address
The parameter is to set an RTU address of the flow meter.
A range of setting of an RTU address is from 001 to 247（0001H to 00F7H）.

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Ultrasonic Flow meter for Fuel Gas Management UX
12. [Address 010FH] Flow rate conversion selectThe parameter is to set a Actual flow rate, normal conversion flow rate, and standard
conversion flow rate for the flow rate conversion.
With settings of the flow rate conversion select and the conversion reference temperature,
you can select a Actual flow rate, normal conversion flow rate, and standard conversion
flow rate.
Actual flow
conversion
select0x0000 (Notselect)Conversion Reference
Temperature-

0x0000 (0.0°C)

0x0001 (Select)

Conversion reference
pressure

0x0000 (0.00kPa)

Other than 0x0000(0.0°C)-

Flow rate
Actual flow rate
Normal conversion
flow rate
Standard
conversion flow rate

When you select “with” conversion, “Normal” or “Standard” display above the partitionline turns on. The integrated flow rate/instantaneous flow rate display/output signal
correspond to the conversion flow rate together.
When you select “without” conversion, “Normal” or “Standard” display above the partitionline turns off. The integrated flow rate/instantaneous flow rate display/output signal
correspond to the Actual flow rate together.
Be careful because if you set the flow rate conversion select (in a case where youaccess the internal address 010FH of the flow rate conversion by means of the function
code 06 or 10 even if you do not change the setting),a pulse constant automaticallyswitches to the setting of 1000[L/P].
Example: A case where you switch to Conversion from No conversion
Pulse constant 10L/P, No conversion↓ Select Conversion.
Pulse constant 1000L/P, normal flow rate or standard flow rate

13. [Address 0110H] Used gas pressure set value（gage）
When you set this parameter, set a 100x value.
With 2byte data, setting is possible in the following ranges:
100x value within 0 to 100.00[kPa] 0000H to 2710H

14. [Address 0111H] Test mode time selectThe parameter is to select a valid period of the test mode, “3 minutes (0000H)”, “60minutes (0001H”, or “Unlimited (0002H)”.
The test mode is designed to simply perform sensing of any piping leak by temporarily
cancelling the low flow cut-off. For details, refer to “4‐2．Measuring Microflow Rate (TestMode)” in the instruction manual.

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Ultrasonic Flow meter for Fuel Gas Management UX
15. [Address 0112H] Conversion reference pressure（gage）
The item is to set a specified pressure that serves as a reference at the time of
conversion.
When you set this parameter, set a 100x value.
Setting is possible in in the range of 0.01 kPa, in the range of 100x values 0x0000 to
0x03E8 of 0.00 to 10.00kPa.
The conversion reference pressure is valid only when you select “Yes (Normal or
standard flow rate)” for [Address 010FH] Actual flow conversion select.
When you select “No (Actual flow rate）” for Actual flow conversion select, you maychange a conversion reference pressure, but the change is not reflected in the flow rate
conversion.
16. [Address 0113H, 0114H] Integration value upper limit alarm threshold
The parameter is to set an integration value upper limit alarm threshold.
When you set this parameter, set a 100x value.
With 4byte data, setting is possible in the range of 100x values 00000000H to
000F423FH of 0 to 9999.99[m3/h].
An address is assigned to each of upper 2 bytes and lower 2 bytes.
[Address 0113H]: Integration value upper limit alarm threshold (Upper)[Address 0114H]: Integration value upper limit alarm threshold (Lower)
You can set upper level only or lower level only. Note, however, that a settable range isdetermined as the 4byte data.
Example) Upper 0005H, Lower 9876H→Integration value upper limit alarm
threshold=00059876H→3667.10[m3/h]
If you try to change only the upper bytes to 000FH, setting is not allowed due to out ofsetting range.
Alarm output upper limit=000F9876H→10220.70[m3/h]>9999.99[m3/h]

17. [Address 0115H] Alarm output selectThe item is to set function assignment of contact output to “Flow rate upper and lower
limit alarm（0000H）”or “Integration value upper limit alarm (0001H)”.

18. [Address 0116H] Gas species selectThe parameter is to set “13A (0000H)”, “Propane (0001H)”, “Butane (0002H)”, “Nitrogen(0003H)”, “Air (0004H)”.
Since the specified gas species is set at the time of factory shipment, you do not have tochange it.
In addition, “Air”in the choices is intended for maintenance, no use with “Air” is allowed.

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Ultrasonic Flow meter for Fuel Gas Management UX

7.2.3 Flowmeter information, Clearing

For the flow meter information, internal information can be acquired. Therefore, thefollowing function code can be used.
Code(hex)

Function

03

Read out a parameter

In addition, for clearing, the following function can be used.
Code(hex)

Function

05

Cancel the integration
value upper limit alarm

Function
code
(hex)

Address
Area Name(hex)

Instantaneous flow rate
(Upper 2 bytes)
Instantaneous flow rate
(Lower 2 bytes)

0200
0201

0202

03

0204
0205
0206
0207
0208
0209

05

Flow meter information

0203

Function

Description
Signed 4-byte data (long type)100x value

Used gas pressure set value(2 bytes)

Unsigned 2-byte data
(unsigned int type) 100 x
value

Temperature (2 bytes)

Signed 2-byte data (int type)10x value

Positive integration value ①(Upper 2 bytes of 6-byte data)
Positive integration value ①(Middle 2 bytes of 6-byte data)

Unsigned 6-byte data

Positive integration value ①(Lower 2 bytes of 6-byte data)

Trip integration value ①(Upper 2 bytes of 6-byte data)

Trip integration value ①(Middle 2 bytes of 6-byte data)

Unsigned 6-byte data

Trip integration value ①(Lower 2 bytes of 6-byte data)

020A

Error information (2 bytes)

0300

Integration
value upper Cancel the integration value
limit
upper limit alarm.
alarm cancel-22-

Unsigned 2-byte data
(unsigned int type)0000 ：Cancel the integration
value upper limit alarmUltrasonic Flow meter for Fuel Gas Management UX
1. [Address 0200H, 0201H] Instantaneous flow rate
The item is the instantaneous flow rate corresponding to [Address 010FH] Actual flow
conversion select. For signed 4-byte data, the flow meter responds with a 100x valueof an actual value.
Each of the upper 2 bytes and lower 2 bytes of the 4-byte data can be read out separately.
(Example) Case of the instantaneous flow rate 123.45[m3/h](123.45×100=12345(dec)→00003039(hex))- Read-out data for the upper2 bytes: 0000H- Read-out data for the lower 2 bytes: 3039H- Read-out data for the 4 bytes: 00003039H

2. [Address 0202H] Pressure [kPa]
This is [Address 0110H] Used gas pressure set value (gage).
For unsigned 2-byte data, the flow meter responds with a 100x value.
(Example) Case of pressure 3.00[kPa] (3.00×100=300(dec)→012C(hex))- Read-out data: 012CH

3. [Address 0203H] Temperature [°C]
For signed 2-byte data, the flow meter responds with a 10x value of the actual value.
(Example) Case of temperature-9.4[°C] (-9.4×10=-94(dec)→ FFA2 (hex))- Rad-out data: FFA2H

4. [Addresses 0204H, 0205H, 0206H] Positive integration value ① 6-byte data
[Addresses 0207H, 0208H, 0209H] Trip integration value ① 6-byte data
These are the integration flow rates corresponding to [Address 010FH] Actual flow
conversion select. For unsigned 6-byte data, the flow meter responds with a 1 to 100x
value of the actual value.
Each of the upper 2 bytes, middle 2 bytes, and lower 2 bytes of the 6-byte data can beread out separately.
Since a multiple varies depending on [Address 010FH] Actual flow conversion select,refer to the table below.

100x value
hex: 0254 0BE3 FFFFH
dec: 2,559,999,999,999

In addition, even if respective integration value displays overflow, true integration values
are read out as the read-out values.
Example) Read-out value: Case of 00086B76CF28H
Positive
Trip integration
integration value
value[100x value] 361626867.60
361626867.60*The underlined italic parts are displayed values.

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5. [Address 020AH] Error information
The item is to read out a state of the flow meter.
For 2-byte data, each bit represents the following error information. In the case ofabnormality, the bit is 1, and in the case of no abnormality or in the case of no use, the bit
is 0.
B15～B7

Unused: At the time of
不使用：読み出し時
read-out

B6

B5

B4

B3

B2

B1

B0
Ultrasonic measurement abnormality (0: Normal, 1:
超音波計測異常(0：正常、1：異常)Abnormal)Temperature measurement abnormality (0: Normal, 1:
温度計測異常(0：正常、1：異常)Abnormal)Unused:At the time of read-out※
Supply power drop (0: Normal, 1: Abnormal)0

電源電圧低下(0：正常、1：低下)

Flow rate upper/lower limit alarm (0: No alarm, 1: Alarm)
流量上下限警報(0：警報なし、1：警報あり)
Internal
dada abnormality (0: Normal, 1: Abnormal)

内部ﾃﾞｰﾀ異常(0：正常、1：異常)Integration
value upper limit alarm (0: No alarm, 1: Alarm)
積算値上限警報(0：警報なし、1：警報あり)

6. [Address 0300H] Integration value upper limit alarm clear
The item is to clear the integration value upper limit alarm.
For set data, only a clear command by 0000H is accepted.

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8 Factory Default Settings List of Set Values
0100

Conversion Reference Temperature

Setting Value
Contents
0°C

0101

Output Pulse Constant

1000L/P

0003H

0102

Alarm output contact state

N.O

0000H

0103

Alarm output upper limit

0104

Alarm output upper limit

0105

Alarm output lower limit

0106

Alarm output lower limit

0107

Alarm output hysteresis width

Address(hex)

Parameter

9999.9 m3/h
0 m3/h0 m3/h

hex
0000H

0001H
869FH
0000H
0000H
0000H
0000H

0108

Alarm output hysteresis width

0109

Instantaneous flow moving average times

010A

Analog output full-scale flow rate

010B

Analog output full-scale flow rate

010C

Analog output switching

Instantaneous flow rate

0000H

010D

Communication bit rate

9600bps

0001H

010E

RTU address

001

0001H

010F

Actual flow rate conversion selectNo conversion

0110

Used gas pressure set value (gage)

10kPa

0000H
03E8H

0111

Test mode time select3 minutes

0000H

0112

Conversion reference pressure (gage)Integration value upper limit alarm threshold(Upper 2 bytes)
Integration value upper limit alarm threshold(Lower 2 bytes)

0kPa

0000H

0113
0114
0115

Alarm output select0116

Gas species select4 times
6 m3/h

0000H
003CH

000FH
9999.99
Flow rate upper/lower limit
alarm*The gas species that you
specified at the time orordering is set.

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0004H

423FH
0000H

Ultrasonic Flow meter for Fuel Gas Management UX

9 Calculation of Error Check Code (CRC-16)

9.1 Overview
The Modbus RTU protocol includes an error check code based on the CRC method in each message.
The error check code consists of 16 bits, is calculated by the transmitting side, and is added to themessage. The
receiving side recalculates a CRC based on the received message and compares the result of thecalculation with the actually received error check code. If the two values do not match, it is determinedthat an error has occurred.
CRC calculation is performed, starting with the RTU address at the head of the message to the tail endof the data. For the calculation, only 8 bits of each characters are used, and start and stop, and parity bit
are not applied to the CRC.
When the error check code is added to the message, the lower byte of the calculation result is added
first, followed by the upper byte.

Start

RTU
address

Function
code

Data

Error check
code

End

Silentinterval

1 byte1 byten bytes

2 bytes

SilentInterval

9.2 Calculation Procedure① Initializes the CRC code to “FFFFH.”② Calculates an exclusive OR (XOR) with the lower 1 byte of the CRC code and the firstcharacter of the message, and store it in the CRC code.
③ Proceeds to ④ if the least significant bit of the CRC code is “1.”Proceeds to ⑤ if the least significant bit of the CRC code is “0.”④ Shift the CRC code to the right by 1 bit. Then, calculates exclusive OR with the generating
polynomial A001H and store it in the CRC code.→Proceed to ⑥.
⑤ Shift the CRC code to the right by 1 bit.→Proceed to ⑥.
⑥ Repeat steps ③→④ or ⑤ until the CRC code is shifted by 8 bits.
⑦ Repeat steps ② to ⑥ similarly for the second and subsequent characters, and apply to
all characters in the calculation range.
⑧ A value that finally remains in the CRC code is the error check code.

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Ultrasonic Flow meter for Fuel Gas Management UX<Calculation Example>
When a message is 01 03 02 01 09 (hex), the CRC code is to be D279H.
Since the lower bytes of the calculation result is first added, the transmission data is to be 01 03
02 01 09 79 D2.
[Details]
The following figure illustrates contents of the calculation of the first and second characters (01and 03):MSB
0 0 0 0 0 0 0 1
exor

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

01
FFFF

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0
0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1First character
1ｷｬﾗｸﾀ目① CRCｺｰﾄﾞ
CRC codeexor② CRCｺｰﾄﾞ
CRC code>>1

CRC code⑤ CRCｺｰﾄﾞ

exor
exor

0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1>>1

1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1

0xA001

1 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0

exor
>>1

0 0 1 0 0 1 1 1 1 1 1 1 1 1 1 1>>1

1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1

0xA00103

CRCｺｰﾄﾞCRC code

1 0 0 0 0 0 0 0 0 1 1 1 1 1 0 1② CRCｺｰﾄﾞ
CRC code0 1 0 0 0 0 0 0 0 0 1 1 1 1 1 0>>1

1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1

0xA001
CRC code④ CRCｺｰﾄﾞ0 1 1 1 0 0 0 0 0 0 0 1 1 1 1 1>>1

1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1

0xA001

CRC code⑤ CRCｺｰﾄﾞ

1 1 0 1 0 0 0 0 0 0 0 1 1 1 1 0
exor

1 0 0 0 0 1 1 1 1 1 1 1 1 1 1 0

0 1 1 0 1 0 0 0 0 0 0 0 1 1 1 1④ CRCｺｰﾄﾞ
CRC codeexor

0 1 0 0 0 0 1 1 1 1 1 1 1 1 1 1>>1

0 0 1 0 0 0 0 1 1 1 1 1 1 1 1 1>>1

1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1

0xA001④ CRCｺｰﾄﾞ
CRC code>>1

0 0 1 1 0 1 0 0 0 0 0 0 0 1 1 1>>1

1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1

0xA001

1 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0

0 1 0 0 1 0 1 0 0 0 0 0 0 0 1 1
CRC code④ CRCｺｰﾄﾞexor
0 1 0 0 0 0 0 0 1 1 1 1 1 1 1 1>>1

0 0 1 0 0 0 0 0 0 1 1 1 1 1 1 1>>1

1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1

0xA001

CRC code④ CRCｺｰﾄﾞ>>10 0 1 0 0 1 0 1 0 0 0 0 0 0 0 1>>1

1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1

0xA001

1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0

CRC code⑤ CRCｺｰﾄﾞ

CRC code⑤ CRCｺｰﾄﾞ

1 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0
exor⑤ CRCｺｰﾄﾞ
CRC code

CRC code⑤ CRCｺｰﾄﾞ

1 0 0 1 0 1 0 0 0 0 0 0 0 1 1 0
exor

Second character2ｷｬﾗｸﾀ目

1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0

1 1 1 0 0 0 0 0 0 0 1 1 1 1 1 1④ CRCｺｰﾄﾞ
CRC code0 1 0 0 1 1 1 1 1 1 1 1 1 1 1 1

LSB
0 0 0 0 0 0 1 1

CRC code
CRCｺｰﾄﾞCRC code④ CRCｺｰﾄﾞ0 1 0 0 0 0 1 0 1 0 0 0 0 0 0 0>>1

CRC code⑤ CRCｺｰﾄﾞ0 0 1 0 0 0 0 1 0 1 0 0 0 0 0 0>>1⑤ CRCｺｰﾄﾞ
CRC code

When the third to fifth characters are calculated in a similar manner, the CRC code will be D279H.

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