FC101 Design Guide

Response
The normal response is an echo of the query, returned
after the register contents have been passed.
Field name Example (hex)
Slave address 01
Function 06
Register address HI 03
Register address LO E7
Preset data HI 00
Preset data LO 01
Error check (CRC) –
Table 7.31 Response
7.10.6 Preset Multiple Registers (10 hex)
Description
This function presets values into a sequence of holding
registers.
Query
The query telegram species the register references to be
preset. Register addresses start at 0, that is, register 1 is
addressed as 0. Example of a request to preset 2 registers
(set parameter 1-24 Motor Current to 738 (7.38 A)):
Field name Example (hex)
Slave address 01
Function 10
Starting address HI 04
Starting address LO 07
Number of registers HI 00
Number of registers LO 02
Byte count 04
Write data HI (Register 4: 1049) 00
Write data LO (Register 4: 1049) 00
Write data HI (Register 4: 1050) 02
Write data LO (Register 4: 1050) E2
Error check (CRC) –
Table 7.32 Query
Response
The normal response returns the slave address, function
code, starting address, and quantity of registers preset.
Field name Example (hex)
Slave address 01
Function 10
Starting address HI 04
Starting address LO 19
Number of registers HI 00
Number of registers LO 02
Error check (CRC) –
Table 7.33 Response
7.10.7 Read/Write Multiple Registers (17
hex)
Description
This function code performs a combination of 1 read
operation and 1 write operation in a single MODBUS
transaction. The write operation is performed before read.
Query
The query message species the starting address and
number of holding registers to be read as well as the
starting address, number of holding registers, and the data
to be written. Holding registers are addressed starting at
zero. Example of a request to set parameter 1-24 Motor
Current to 738 (7.38 A) and read parameter 3-03 Maximum
Reference which has value 50000 (50,000 Hz):
Field name Example (hex)
Slave address 01
Function 17
Reading starting address HI 0B (Register address 3029)
Read starting address LO D5 (Register address 3029)
Quantity to read HI 00
Quantity to read LO
02
(Parameter 3-03 Maximum
Reference is 32 bits long, that is,
2 registers)
Write starting address HI 04 (Register address 1239)
Write starting address LO D7 (Register address 1239)
Quantity to write HI 00
Quantity to write LO 02
Write byte count 04
Write registers value HI 00
Write registers value LO 00
Write registers value HI 02
Write registers value LO 0E
Error check (CRC) –
Table 7.34 Query
Response
The normal response contains the data from the group of
registers that were read. The byte count eld species the
quantity of bytes to follow in the read data eld.
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