English (GB)
32
Example of response from master to slave
The response is identical to the request.
Example of response from slave to master
12.7 Diagnostics register interpretation
The diagnostics register is interpreted as follows:
A bit value of 1 means true, unless otherwise specified.
The diagnostics register is read using function code 0x08 and
subcode 0x02.
12.8 Diagnostics: return query data
This function is useful to ensure that the communication path and
slave configuration are correct. It will echo the request in the
response.
In the example, slave address 0x01 is used.
Request from master to slave
Example of response from slave to master
If there is no response from the slave, see section
.
12.9 Reading the CIM configuration register block
This section shows how to read the first four registers of the CIM
configuration register block.
In the example, slave address 0x01 is used.
Request from master to slave
Example of response from slave to master
If there is no response from the slave, see section
.
Field
Value
Address
0x01
Function code
0x08
Subcode
0x00
Data
0xAB
Data
0xCD
Field
Value
Address
0x01
Function code
0x08
Subcode
0x00
Data
0xAB
Data
0xCD
Bit
Description
0
Internal communication failure (with the Grundfos
CIU 250).
1
EEPROM self-test failed (the test is carried out when
the system is booted).
2
Grundfos CIU 250 not supported.
3
Modbus address offset is different from default value,
i.e. it differs from 0.
4
Using software-defined Modbus transmission speed.
5
RESERVED
6
RESERVED
7
RESERVED
8
RESERVED
9
RESERVED
10
RESERVED
11
RESERVED
12
RESERVED
13
RESERVED
14
RESERVED
15
RESERVED
Field
Value
Description
Slave address
0x01
-
Function code
0x08
Diagnostics
Subcode
0x00
Echo request
Data
0xAB
Test data
Data
0xCD
Test data
Field
Value
Description
Slave address
0x01
-
Function code
0x08
Diagnostics
Subcode
0x00
Echo request
Data
0xAB
Test data
Data
0xCD
Test data
Field
Value
Description
Slave address
0x01
-
Function code
0x04
Read input registers
Start address HI
0x00
Start address
= 0x0001
Start address LO
0x00
Quantity HI
0x00
Number of registers
= 0x0004
Quantity LO
0x04
Field
Value
Description
Slave address
0x01
-
Function code
0x04
Read input registers
Byte count
0x08
8 bytes follow
00001 HI
0x00
SlaveMinimumReplyDelay
= 0x000A
00001 LO
0x0A
00002 HI
0x00
RegisterOffset
= 0x0000
00002 LO
0x00
00003 HI
0x00
Reserved value
= 0x0000
00003 LO
0x00
00004 HI
0x00
ModbusBitRate
= 0x0004
00004 LO
0x04
