Name: Danfoss VLT Micro Drive FC 51 Series
Brand: Danfoss
Rating: 4 (1 reviews)

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5.5.1 Read Coil Status (01

HEX

)

Description

This function reads the ON/OFF status of discrete outputs (coils) in the frequency converter. Broadcast is never supported for reads.

Query

The query messages specifies the staring coil and quantity of coils to be read. Coil addresses start at zero, i.e. coil 33 is addressed as 32.

Example of a request to read coils 33-48 (Status Word) from slave device

01:

Field Name Example (HEX)

Slave address 01 (frequency converter address)

Function 01 (read address)

Starting Address HI 00

Starting Address LO 20 (32 decimal)

No. of Points HI 00

No. of Points LO 10 (16 decimal)

Error Check (CRC) -

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 will padded with zeros (toward the high order and 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) -

5.5.2 Force/Write Single Coil (05

HEX

)

Description

This function forces a 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, i.e. 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 (coil no. 65)

Force Data HI FF

Force Data LO 00 (FF 00 = ON)

Error Check (CRC) -

Response

The normal response is an echo of the query, returned after the coil state has been forced.

VLT