Force/Write Multiple Coils (0F Hex); Read Holding Registers (03 Hex) - Danfoss VLT HVAC Basic Drive FC 101 Design Manual

RS-485 Installation and Set...

7.10.3 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
setpoint) to be forced.
Field Name Example (HEX)
Follower Address 01 (adjustable frequency drive
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 7.25 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 (adjustable frequency drive
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 7.26 Response
MG18C522
Design Guide

7.10.4 Read Holding Registers (03 HEX)

Description
This function reads the contents of holding registers in the
follower.
Query
The query message specifies the starting register and
quantity of registers to be read. Register addresses start at
zero, that is, registers 1-4 are addressed as 0-3.
Example: Read 3-03 Maximum Reference, register 03030.
Field Name
Follower Address
Function
Starting Address HI
Starting Address LO
No. of Points HI
No. of Points LO
Error Check (CRC)
Table 7.27 Query
Response
The register data in the response message are packed as
two bytes per register, with the binary contents right
justified within each byte. For each register, the first byte
contains the high-order bits and the second contains the
low-order bits.
Field Name
Follower Address
Function
Byte Count
Data HI (Register 3030)
Data LO (Register 3030)
Data HI (Register 3031)
Data LO (Register 3031)
Error Check (CRC)
Table 7.28 Response
Danfoss A/S © Rev. 2014-01-14 All rights reserved.
Example (HEX)
01
03 (read holding registers)
0B (Register address 3029)
05 (Register address 3029)
00
02 - (3-03 Maximum Reference is 32 bits
long, i.e., two registers)
-
Example (HEX)
01
03
04
00
16
E3
60
-
7 7
101