February 06 2023
Document No.TS-AS-WC-001
version.1.0

Ultrasonic Flow Meter For Natural Gas and Factory Air
AS-W( For Natural Gas ) AS-C( For Factory Air )MODBUS RTU Communication Specifications

Aichi Tokei Denki Co.,Ltd.

1.

Communication Specifications
InterfaceCommunication method
Synchronization method
Connection topology
Communication mode
Transmission speed [bps]Bit length [bits]
Stop bit [bits]
ParitySending/receiving buffer size [bytes]
Response time [s]2.

Message frame configuration
Start
Address
Silent interval *1 byteEIA RS485 compliant
Half-duplex
Asynchronous
1: N (Unbalanced bus connection)
Modbus RTU
Selectable from the following by parameter setting:
4800, 9600
8
1
N/A
100
3 (max)Function code
1 byteDatan bytes

CRC checkEnd
2 bytes
Silent interval ** Silent communication for 3.5 characters or more

<Address>
Specify the RTU address set for the flowmeter. 00H is set at the time of shipment.
<Function code>
The following function codes are available. Other codes are not available.
Code (Hex)Function
03
Reading of parameters, flowmeter information, and history information
06
Writing of a single parameter10
Writing of multiple parameters
Note that the broadcast function is not available by all of the function codes.
<Data>
Used to transmit date associated with a function code. The data length is variable and there is no data if it’s not associated with afunction code.
<CRC check>
Error check is performed in the CRC method. CRC is 16-bit binary value and is calculated and added by the sender side. The receivercalculates the CRC value from the sent message and compares with the sent CRC value. An error is declared if these two values do
not match.

1

3.Internal address and data details
Function code
Address(Hex)(Hex)
0000～00FF
0100

03 or 06 or 10

Area name

Function

Parameter

Working pressure set value
valid/invalid

Details

System area

0101

Working pressure [abs]0102

Output pulse constant

0103

Flow-rate compensation
selection

0104

Selection of flow value forpulse output

0105

Instantaneous flow-ratemoving average number of
times

0106

Compressibility
factor fixed value

0107

Communication bit rate

0108

RTU address

0109

Low flow cutoff value

0x0000: Invalid
0x0001: Valid0x0000 to 0x2710(0.0 to 1000.0 [kPa], Set value multiplied by 10)
0x0004: 100L/P
0x0005: 1000L/P
0x0006: 10000L/P
0x0000: Without compensation(Actual flow)
0x0001: With compensation
0x0000: Instantaneous flow-rate withoutcompensation.
0x0001: Instantaneous flow-rate withcompensation.
0x0001 to 0x0010(1 to 16 [times])
0x 0000,0x0320 to 0x04B0(0.800 to 1.200, Set value multiplied by 1000.
0x 0000: The compressibility factor calculated bycomposition input is used for flow conversion.）
0000: 4800bps
0001: 9600bps
0x0000 to 0x00FF(0 to 255)
0 to Qmin, Set value multiplied by 100

010A
System area
010B
010C

Selection of Alarm output
contact state

010D

System area

010E

Time setting (year)

0x0000～0xFFFF(Set in A.D.)

010F

Time setting (month)

0x0001～0x000C (January to December)

0110

Time setting (day)0111Time setting (hour)

0112

Time setting (minute)

0x0000～0x003B (0 to 59)

0113

History storage interval

0ｘ0001～0ｘ0120（5 minutes to 24 hours）（Set value×5 minutes＝Storage interval）

0114

System area

0115

Pulse output method and ON
time at one-shot pulse

0116

Pressure value moving
average number of times

0117

System area

20x0000 : Normal open
0x0001 : Normal close

0x0001～0x001F (1st to 31st)
0x0000～0x0017 (0 to 23)

0ｘ0000：One-shot pulse and ON time 1000ms
0ｘ0001：One-shot pulse and ON time 500ms
0ｘ0002：One-shot pulse and ON time 250ms
0ｘ0003：One-shot pulse and ON time 125ms
0ｘ0004：One-shot pulse and ON time 50ms
0ｘ0005：duty50
0x0001～0x0004(1～4[times])

Function code
(Hex)

Address(Hex)

Area name

Function

Parameter

0118

0119

06 or 10

011A

011B

011C

011D

011E
03

011F

Accumulated forward flow
volume (upper 4 digits)
Actual flow specifications：
Accumulated forward actual flow
volumeCompensated specifications：
Accumulated forward
compensated flow volume

Accumulated forward flow
volume (middle 4 digits)
Actual flow specifications：
Accumulated forward actual flow
volumeCompensated specifications：
Accumulated forward
compensated flow volume

Accumulated forward flow
volume (lower 4 digits)
Actual flow specifications：
Accumulated forward actual flow
volumeCompensated specifications：
Accumulated forward
compensated flow volume

Set upper 4 digits of accumulated display digits indecimal system. Refer to the following when set
value 4 digits are shown as WXYZ

W
X
Y
Z

Digit position
25A～80A
100A～200A
00000
109 digits
107 digits
108 digits

Set middle 4 digits of accumulated display digits
in decimal system. Refer to the following whenset value 4 digits are shown as WXYZ

W
X
Y
Z

Digit position
25A～80A
100A～200A
106 digits
107 digits
5
10 digits
106 digits
4
10 digits
105 digits
3
10 digits
104 digits

Set lower 4 digits of accumulated display digits indecimal system. Refer to the following when set
value 4 digits are shown as WXYZ

W
X
Y
Z

Digit position
25A～80A
100A～200A
102 digits
103 digits
1
10 digits
102 digits
0
10 digits
101 digits-1
10 digits
100 digits

Accumulated forward flow
volume (upper 2 bytes)
Actual flow specifications：
Accumulated forward volume
compensated flow volume
Compensated specifications：
Accumulated forward actual flow
volumeAccumulated forward flow
volume (lower 2 bytes)
Actual flow specifications：
Accumulated forward
compensated flow volume
Compensated specifications：
Accumulated forward actual flow
volumeUnsigned 4-byte data, Value multiplied by 10

Accumulated reverse
compensated flow volume(upper 2 bytes)
Accumulated reverse
compensated flow volume(lower 2 bytes)

Unsigned 4-byte data, Value multiplied by 10

Software version

Not configurable, read only

0120
0121

Details

System area

0122
3

Function code
(Hex)

Address(Hex)

Area name03 or 06 or 10

0123

Parameter

0124
0125～012E
03 or 06 or 10

012F

Parameter

Function
Compensated standard
temperature
Compensated standard
pressure (Gauge pressure)
System area

N2

0131

C02

0132

C2H6

0133

C3H8

0134

i-C4H100135

ｎ-C4H100136

i-C5H120137

ｎ-C5H12

0138

C6H14

0139

C7H16

013A

C8H18

013B

C9H20

013C

C10H22

013D

H2

013E

O2

013F

CO

0140

H2O

0141

H2S

0xFF9C～0x0258(+/-Signed data)(-10.0～+60.0[℃]、Value multiplied by 10)
0x0000～0x03E8(0.00～10.00kPa, Value multiplied by 100)0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)

CH4

0130

Details4

Function code
(Hex)

Address(Hex)

03 or 06 or 10

0142

He(Helium)

0143

Ar(Argon)

Area name

Function

0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)
0x0000～0x03E8(0.000～1.000[Mole fraction],Value multipliedby 1000)

Parameter

0144～01FE
03

0203

System area
Instantaneous actual flow-rate(upper 2 bytes)
Instantaneous actual flow-rate(lower 2 bytes)
Instantaneous compensatedflow-rate (upper 2 bytes)
Instantaneous compensatedflow-rate (lower 2 bytes)
Pressure (upper 2 bytes)

0204

Pressure (lower 2 bytes)

0205

Temperature (upper 2 bytes)

0206

Temperature (lower 2 bytes)
Accumulated forward actual
flow volume (upper 2 bytes)
Accumulated forward actual
flow volume (lower 2 bytes)
Accumulated forward
compensated flow volume(upper 2 bytes)
Accumulated forward
compensated flow volume(lower 2 bytes)
Accumulated reverse
compensated flow volume(upper 2 bytes)
Accumulated reverse
compensated flow volume(lower 2 bytes)

0１FF
0200
0201
0202

0207
0208

Flowmeter
information

0209

020A

020B

020C
020D

Error information (2 bytes)
Sound velocity information (2bytes)
System area

020E
020F～021E
03

021F

Flowmeter
information

Model information 1

0220

Model information 2

0221

Serial number 1

0222

Serial number 2

0223

Serial number 30224～03FF

Details

System area5+/- signed 4-byte data (long type)
Value multiplied by 100+/- signed 4-byte data (long type)
Value multiplied by 100+/- signed 4-byte data (long type)
Valued multiplied by 100+/- signed 4-byte data (long type)
Valued multiplied by 100
Unsigned 4-byte data (unsigned long type)
Value multiplied by 10 (Value multiplied by 1 forbigger size than AS-W,-C-100)

Unsigned 4-byte data (unsigned long type)
Value multiplied by 10 (Value multiplied by 1 forbigger size than AS-W,-C-100)

Unsigned 4-byte data (unsigned long type)
Valued multiplied by 10 (Value multiplied by 1
for bigger size than AS-W,-C-100)
Unsigned 2-byte data (unsigned int type)
Unsigned 2-byte data (unsigned int type)
Valued multiplied by 100
Unsigned 2-byte data
upper 1 byte：Nominal diameterlower 1 byte：Version
Unsigned 2-byte data
Pressure type+Pressure
Unsigned 2-byte data
upper 1 byte：Year of manufacture
lower 1 byte：Month of manufacture
Unsigned 2-byte data
upper 1 byte：By size of nominal diameter＋
Versionlower 1 byte：5-digit number（upper）
Unsigned 2-byte data
5-digit number（lower）

Function code
(Hex)

Address(Hex)

Area name

Function

Details

Instantaneous compensatedflow-rate (4 bytes)+/- signed 4-byte data (long type)
Value multiplied by 100+/- signed 4-byte data (long type)
Value multiplied by 100+/- signed 4-byte data (long type)
Value multiplied by 100
Unsigned 4-byte data (unsigned long type)
Value in accordance with the flow compensation
selection, multiplied by 10
Unsigned 2-byte data (unsigned int type)+/- signed 4-byte data (long type)
Value multiplied by 10 (Value multiplied by 1 forbigger size than AS-W,-C-100)+/- signed 4-byte data (long type)
Value multiplied by 10 (Value multiplied by 1 forbigger size than AS-W,-C-100)
Unsigned 2-byte data
Unsigned 2-byte data
Upper 1 byte: Month
Lower 1 byte: Day
Unsigned 2-byte data
Upper 1 byte: Hour
Lower 1 byte: Minute+/- signed 4-byte data (long type)
Value multiplied by 10 (Value multiplied by 1 forbigger size than AS-W,-C-100)+/- signed 4-byte data (long type)
Value multiplied by 10 (Value multiplied by 1 forbigger size than AS-W,-C-100)+/- signed 4-byte data (long type)
Value multiplied by 10 (Value multiplied by 1 forbigger size than AS-W,-C-100)

Pressure (4 bytes)
Temperature (4 bytes)
Accumulated forward flow
volume (4 bytes)
Error information (2 bytes)
Instantaneous actual flow-rate(4 bytes)
Accumulated forward actual
volume (4 bytes)
03

0400

History 1

Storage time (year)
Storage time (month/ day)

Storage time (hour/ minute)Accumulated forward
compensated volume of theacquisition interval (4 bytes)
Accumulated forward actual
volume of the acquisitioninterval (4 bytes)
Accumulated reverse
compensated volume (4 bytes)

03

0401
0402

History 2
History 3

Refer to ‘History 1’ for details
Refer to ‘History 1’ for details

１DC7

History
6600

Refer to ‘History 1’ for details

1DC8～FFFF

System area

6

4.Function Codes
4-1. Reading of parameters, flowmeter information, and history information (03H)
Reads parameters, flowmeter information, and history information.
The following shows an example of reading the communication bit rate (0x0107) and RTU address.
<Query configuration>
Field name
Start
Slave address
Function code
Start address (upper)
Start address (lower)
Number of registers (upper)
Number of registers (lower)
Error check
Error check
End

Data example (Hex)
N/A
05
03
01
07
00
02
(CRC) (lower)(CRC) (upper)
N/A<Response configuration>
Field name
Start
Slave address
Function code
Number of data bytes
Data at address 0x0107 (upper)
Data at address 0x0107 (lower)
Data at address 0x0108 (upper)
Data at address 0x0108 (lower)
Error check
Error check
End

Data example (Hex)
N/A
05
03
04
00
01
00
05
(CRC) (lower)(CRC) (upper)
N/A*1 Reading of history information
When reading of “history 1～6600”, only ”0001” is available at number of registers.
*2 Details of flowmeter information and history information
 Instantaneous actual flow-rate: +/- signed 4-byte value, multiplied by 100(Example) 0x00003039 → 123.45 [m3/h], 0xFFFE7E33 → -987.65 [m3/h]
 Pressure: +/- signed 4-byte value, multiplied by 100(Example) 0x00003039 → 123.45 [kPa] (abs) Temperature: +/- signed 4-byte value, multiplied by 100(Example) 0x000004D2 → 12.34 [℃], 0xFFFFFC50 → -9.45 [℃]Accumulated forward actual volume, accumulated forward compensated volume, and accumulated reverse compensatedvolume: Unsigned 4-byte value, multiplied by 10(Example) 0x075BCD15 → 12345678.9 [m3]
 Error information: 2-byte value and each bit have error information. “1” is indicated for error condition, and “0” is indicatedfor normal condition. Unused bit is read as “0” or indefinite value.
B15

B14

Bit name
B0
B1
B2
B3
B4
B5
B6
B7

B13

B12

B11

B10

B9

B8

B7

Details

B6

Bit name
B8
B9
B10
B11

Disuse: Read as 0
Disuse: Read as indefinite value
EEPROM error (0: Normal, 1: Error)
Low battery voltage(0: Normal, 1: Low battery)Pressure measurement failure(0: Normal, 1: Error)
Temperature measurement failure(0: Normal, 1: Error)
Ultrasonic measurement failure(0: Normal, 1: Error)

B5

B4

B3

B14
B15
7

B1

Details
Disuse: Read as indefinite value

B12
B13

B2

Disuse: Read as 0

B0

*3

Details of model information and Serial number●Model information 1(upper 1 byte：Nominal diameter,lower 1 byte：Version)
Nominal diameter
Detail
25A
32A
40A
50A
80A
100A
Readout
0x19
0x20
0x28
0x32
0x50
0x64

150A
0x96

●Model information 2（upper 0.5 byte：Pressure type,lower 1.5 byte：Pressure）
Pressure typePressure
DetailA
0200
500
Readout
0x0
0x000
0x0C8
0x1F4

200A
0xC8

1000
0x3E8

●Serial number 1(upper 1 byte：year of manufacture,lower 1 byte：Month of manufacture)
Year of manufacture
Month of manufacture（last two digits of the year ）Detail
2019
January
DecemberReadout
0x13
0x01
0x0C
●Serial number 2(upper 1 byte：size of nominal diameter + version,lower 1 byte：5-digit number(upper))Size of nominal diameter
VersionDetailS
M
L
Ver.5
Readout
0x0
0x1
0x2
0x05
●Serial number 3(5-digit number(lower))(Example) 5-digit numbe=67890（0x10932）
Serial number 2=0x**01
Serial number 3=0x0932

4-2. Writing of a single parameter (06H)
Changes (i.e., writes) a single parameter.
The following shows an example of changing “Flow-rate compensation selection” to with compensation.
<Query configuration>
Field name
Start
Slave address
Function code
Start address (upper)
Start address (lower)
Change data (upper)
Change data (lower)
Error check
Error check
End

Data example (Hex)
N/A
05
06
01
03
00
01
(CRC) (lower)(CRC) (upper)
N/A<Response configuration>
Field name
Start
Slave address
Function code
Address (upper)
Address (lower)
Change data (upper)
Change data (lower)
Error check
Error check
End

Data example (Hex)
N/A
05
06
01
03
00
01
(CRC) (lower)(CRC) (upper)
N/A

8

VersionVer.5
0x05

* Details of writing data
Refer to “3. Internal address and data details” for the details of the writing data for the parameter area. The following describes
the item especially be noted.
 Working pressure
The working pressure can be set within a range from 0.0 to 1000.0kPa [abs]. When the working pressure is 500.0kPa, the set
value is 0x1388(hexadecimal representation of 5000 (500×10).
 Output pulse constant
The pulse constant can be chosen from 100, 1000, and 10000L/P.
 RTU address and communication bit rate
In case of changing the RTU address or communication bit rate, the response message to the change order uses the parametersetting before the change and the new setting is used from the succeeding communication.

Example1) When changing the RTU address of the flowmeter from 1 to 2
Query
Response
Field name
Data example (Hex)
Start
N/A
N/A
Slave address
0101
Function code
06
06
Start address (upper)
01
01
Start address (lower)
08
08
Change data (upper)
00
00
Change data (lower)
02
02
Error check(CRC) (lower)(CRC) (lower)
Error check(CRC) (upper)(CRC) (upper)
End
N/A
N/A

Response is returned with 0x01.
The succeeding messages operatewith address = 2.

Example2) When changing the communication bit rate of the flowmeter from 9600bps to 4800bp
Query
Response
Field name
Data example (Hex) Data example (Hex)
Start
N/A
N/A
Slave address
01
01
Response is returned with 9600bps.
Function code
06
06
Start address (upper)
01
01
The succeeding messages are
Start address (lower)
07
07
transmitted at 4800bps
Change data (upper)
00
00
Change data (lower)
00
00
Error check(CRC) (lower)(CRC) (lower)
Error check(CRC) (upper)(CRC) (upper)
End
N/A
N/A

 Low flow cutoff value
The low flow cutoff value can be set up to two decimal place in m3/h units. Use a value multiplied by 100 as the set value.
To set the value to “1.2 [m3/h],” use 0x0078 (hexadecimal representation of 120 (1.2×100)).
The low flow cutoff value can be set within a range from 0 to Qmin [m3/h]. Qmin depends on the nominal diameter. The
available range is as listed below.

Qmin [m3/h]
Upper limit set value
(Hex)

25A
0.7

32A
1.3

40A
1.6

0×0046

0×0082

0×00A09

Nominal diameter
50A
80A
3
6

100A
10

150A
24

200A
40

0×012C

0×03E80×09600×0FA00×0258

○Pulse output method and ON time at one-shot pulse
As for each diameter, set regulation for the set pulse constant is as below.
This setting will be performed after pulse constant setting because this set value will be automatically set as duty50 output whenpulse constant is changed.
○: Selectable

×: Not selectable

<25A>

<32A>

ﾊﾟﾙｽ ON
Pulse
ON
width
[ms]
幅[ms]

Pulse
constant [L/P]
ﾊﾟﾙｽ定数[L/P]
10000

ﾊﾟﾙｽ
PulseON
ON幅
width
[ms]
[ms]

100

1000

50

○

125
250

100

1000

10000

○

○

50

○

○

○

○

○

○

125

○

○

○

○

○

○

250

×

○

○

500

×

○

○

500

×

○

○

1000

×

○

○

1000

×

○

○

<40A>

Pulse
constant [L/P]
ﾊﾟﾙｽ定数[L/P]

<50A>

<80A>

10000

ﾊﾟﾙｽ
PulseON
ON幅
width
[ms]
[ms]

100

1000

○

○

50

○

○

○

○

125

×

○

○

250

500

×

○

○

1000

×

○

○

ﾊﾟﾙｽ ON
Pulse
ON
width
[ms]
幅[ms]

Pulse
constant [L/P]
ﾊﾟﾙｽ定数[L/P]
100

1000

50

○

125
250

<100A>

Pulse
constant [L/P]
ﾊﾟﾙｽ定数[L/P]
10000

ﾊﾟﾙｽ
PulseON
ON幅
width
[ms]
[ms]

100

1000

10000

○

○

50

○

○

○

×

○

○

125

×

○

○

×

○

○

250

×

○

○

500

×

○

○

500

×

○

○

1000

×

○

○

1000

×

×

○

<150A>

Pulse
constant [L/P]
ﾊﾟﾙｽ定数[L/P]

ﾊﾟﾙｽ ON
Pulse
ON
width
[ms]
幅[ms]

100

1000

50

×

125
250

Pulse
constant [L/P]
ﾊﾟﾙｽ定数[L/P]<200A>

10000

ﾊﾟﾙｽ
幅
PulseON
ON
width
[ms]
[ms]

Pulse
constant [L/P]
ﾊﾟﾙｽ定数[L/P]
10000

ﾊﾟﾙｽ
幅
PulseONONwidth[ms][ms]

100

1000

○

○

50

×

×

○

○

125

×

○

○

250

500

×

×

○

1000

×

×

○

100

1000

10000

○

○

50

×

○

○

×

○

○

125

×

×

○

×

×

○

250

×

×

○

500

×

×

○

500

×

×

○

1000

×

×

○

1000

×

×

×

10

Pulseﾊﾟﾙｽ定数[L/P]
constant [L/P]4-3. Writing of multiple parameters (10H)
Changes (i.e., writes) multiple parameters.
The following shows an example of changing the pulse output flow-rate to the instantaneous flow-rate value withoutcompensation, and the instantaneous flow-rate moving average number of times to “3.”<Query configuration>
Field name
Start
Slave address
Function code
Start address (upper)
Start address (lower)
Number of registers (upper)
Number of registers (lower)
Number of bytes
Change data (pulse output flow-rate value
selection) (upper)
Change data (pulse output flow-rate value
selection) (lower)
Change data (Instantaneous flow-rate moving
average number of times) (upper)
Change data (Instantaneous flow-rate moving
average number of times) (lower)
Error check
Error check
End

Data example (Hex)
N/A
05
10
01
04
00
02
04
00
00
00
03
(CRC) (lower)(CRC) (upper)
N/A<Response configuration>
Field name
Start
Slave address
Function code
Start address (upper)
Start address (lower)
Number of registers (upper)
Number of registers (lower)
Error check
Error check
End

Data example (Hex)
N/A
05
10
01
04
00
02
(CRC) (lower)(CRC) (upper)
N/A

Details of writing data for writing multiple parameters are the same as those for writing a single parameter as described in “4-2.
Writing of a single parameter.”5.

Communication Error
When following communication errors are detected, their contents are returned as response messages. No response will be
returned for any other errors than listed below.
Code
0x01
0x02

Name
Improper function
Improper data address

0x03

Improper data

Meaning
The function is not supported.
The address does not exist.
An address exceeding the buffer size is specified.
The specified data is out of range.

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A response returned upon error detection consisted of the function code with its uppermost bit changed to “1” and of the error
code appended to the function code.
Example) When 0x0003 is set for the flow-rate compensation selection. Since set data 0x0003 is out of the available range, an
improper data is returned.
<Query configuration>
Field name
Start
Slave address
Function code
Start address (upper)
Start address (lower)
Change data (upper)
Change data (lower)
Error check
Error check
End

Data example (Hex)
N/A
05
06
01
03
00
03
(CRC) (lower)(CRC) (upper)
N/A<Response configuration>
Field name
Start
Slave address
Function code
Error code
Error check
Error check
End

Data example (Hex)
N/A
05
86
03
(CRC) (lower)(CRC) (upper)
N/A

The uppermost bit of 0x06 is set to “1.”Returns the error contents.

About improper data processing
When improper data is detected while writing a single parameter, the improper data is not set.
When improper data is detected while writing multiple parameters, values preceding the improper data are set but the improper
data and the values following it are not set.
Example1) When writing the pulse output flow-rate value selection = 0x0001 (normal data), instantaneous flow-rate moving
average number of times = 0x0011 (improper data), and compression factor compensation value = 0x0320 (normal data) in
a single operation, the pulse output flow rate value selection is set but the instantaneous flow-rate moving average numberof times and compression factor compensation value are not set.
Example2) When writing the pulse output flow-rate value selection = 0x0002 (improper data), instantaneous flow-rate moving
average number of times = 0x0004 (normal data), and compression factor compensation value = 0x0320 (normal data) in asingle operation, all parameters are not set.

12