Field Name
Example (HEX)
Slave Address
01 (frequency converter address)
Function
01 (read coils)
Starting Address HI
00
Starting Address LO
20 (32 decimals) Coil 33
No. of Points HI
00
No. of Points LO
10 (16 decimals)
Error Check (CRC)
-
Table 8.22
Response
The coil status in the response message is packed as one
coil per bit of the data field. Status is indicated as: 1=ON;
0=OFF. The LSB of the first data byte contains the coil
addressed in the query. The other coils follow toward the
high order end of this byte, and from ‘low order to high
order’ in subsequent bytes.
If the returned coil quantity is not a multiple of eight, the
remaining bits in the final data byte is padded with zeros
(toward the high order end of the byte). The Byte Count
field specifies the number of complete bytes of data.
Field Name
Example (HEX)
Slave Address
01 (frequency converter address)
Function
01 (read coils)
Byte Count
02 (2 bytes of data)
Data (Coils 40-33)
07
Data (Coils 48-41)
06 (STW=0607hex)
Error Check (CRC)
-
Table 8.23
NOTE
Coils and registers are addressed explicit 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 slaves.
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
Example (HEX)
Slave Address
01 (Frequency converter address)
Function
05 (write single coil)
Coil Address HI
00
Coil Address LO
40 (64 decimal) Coil 65
Force Data HI
FF
Force Data LO
00 (FF 00=ON)
Error Check (CRC)
-
Table 8.24
Response
The normal response is an echo of the query, returned
after the coil state has been forced.
Field Name
Example (HEX)
Slave Address
01
Function
05
Force Data HI
FF
Force Data LO
00
Quantity of Coils HI
00
Quantity of Coils LO
01
Error Check (CRC)
-
Table 8.25
8.10.3 Force/Write Multiple Coils (0F HEX)
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.
The query message specifies the coils 17 to 32 (speed set-
point) to be 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)
Byte Count
02
Force Data HI
(Coils 8-1)
20
Force Data LO
(Coils 16-9)
00 (ref.=2000 hex)
Error Check (CRC)
-
Table 8.26
Response
The normal response returns the slave address, function
code, starting address, and quantity of coils forced.
RS-485 Installation and Set...
VLT
®
Micro Drive FC 51 Design Guide
82
MG02K202 - VLT
®
is a registered Danfoss trademark
8
8
Buy: www.ValinOnline.com | Phone 844-385-3099 | Email: [email protected]
