Field Name Example (HEX)
Slave address 01
Function 05
Coil Address HI 00
Coil Address LO 40
Data HI FF
Data LO 00
Error Check (CRC) -
5.5.3 Force/Write Multiple Coils (0F
HEX
)
Description
This function forces each coil in a sequence of coils to either ON or OFF. When broadcast the function forces the same coil references in all attached
slaves.
Query
The query message specifies the coils 17 to 32 (speed set-point) to be forced. Coil addresses start at zero, i.e. coil 17 is addressed as 16.
Field Name Example (HEX)
Slave address 01 (frequency converter address)
Function 0F (write multiple coil)
Coil Address HI 00
Coil Address LO 10 (coil address 17)
Quantity of coils HI 00
Quantity of coils LO 10 (16 coils)
Byte count 02
Force Data HI (coils 8-1) 20
Force Data LO (coils 10-9) 00 (ref. = 2000hex)
Error Check (CRC) -
Response
The normal response returns the slave address, function code, starting address, and quantity of coils forced.
Field Name Example (HEX)
Slave address 01 (frequency converter address)
Function 0F (write multiple coils)
Coil Address HI 00
Coil Address LO 10 (coil address 17)
Quantity of coils HI 00
Quantity of coils LO 10 (16 coils)
Error Check (CRC) -
5.5.4 Read Holding Registers (03
HEX
)
Description
This function reads the content of holding registers in the slave.
Query
The query message specifies the starting register and quantity to be read. Register addresses start at zero, i.e. registers 1-4 are addressed as 0-3.
5 Modbus RTU VLT
®
Micro Drive FC 51 Operating Instructions
32
MG.02.A4.02 - VLT
®
is a registered Danfoss trademark
5