Force/Write Single Coil (05 Hex); Force/Write Multiple Coils (0F Hex); Read Holding Registers (03 Hex) - Danfoss FC 102 Design Manual

Installation and Set-up
NOTICE
Coils and registers are addressed explicitly with an off-
set of -1 in Modbus.
I.e. Coil 33 is addressed as Coil 32.

8.10.2 Force/Write Single Coil (05 HEX)

Description
This function forces the coil to either ON or OFF. When
broadcast, the function forces the same coil references in
all attached followers.
Query
The query message specifies the coil 65 (parameter write
control) to be forced. Coil addresses start at zero, that is,
coil 65 is addressed as 64. Force Data=00 00HEX (OFF) or
FF 00HEX (ON).
Field Name
Follower Address
Function
8 8
Coil Address HI
Coil Address LO
Force Data HI
Force Data LO
Error Check (CRC)
Table 8.23 Query
Response
The normal response is an echo of the query, returned
after the coil state has been forced.
Field Name
Follower Address
Function
Force Data HI
Force Data LO
Quantity of Coils HI
Quantity of Coils LO
Error Check (CRC)
Table 8.24 Response

8.10.3 Force/Write Multiple Coils (0F HEX)

Description
This function forces each coil in a sequence of coils to
either ON or OFF. When broadcasting the function forces
the same coil references in all attached followers.
Query
The query message specifies the coils 17 to 32 (speed set-
point) to be forced.
142
Design Guide
Example (HEX)
01 (Frequency converter address)
05 (write single coil)
00
40 (64 decimal) Coil 65
FF
00 (FF 00=ON)
-
Example (HEX)
01
05
FF
00
00
01
-
Danfoss A/S © Rev. 06/2014 All rights reserved.
Field Name Example (HEX)
Follower 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)
Byte Count 02
Force Data HI 20
(Coils 8-1)
Force Data LO 00 (ref.=2000 hex)
(Coils 16-9)
Error Check (CRC) -
Table 8.25 Query
Response
The normal response returns the follower address, function
code, starting address, and quantity of coils forced.
Field Name Example (HEX)
Follower 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) -
Table 8.26 Response

8.10.4 Read Holding Registers (03 HEX)

Description
This function reads the contents of holding registers in the
following.
Query
The query message specifies the starting register and
quantity of registers to be read. Register addresses start at
zero, i.e. registers 1-4 are addressed as 0-3.
Field Name Example (HEX)
Slave Address 01
Function 03 (read holding registers)
Starting Address HI 0B (Register address 3029)
Starting Address LO D5 (Register address 3029)
No. of Points HI 00
No. of Points LO 02 - (Par. 3-03 is 32 bits long, i.e.
2 registers)
Error Check (CRC) -
Table 8.27 Example: Read 3-03 Maximum Reference, register 03030
MG11BC02