GE Industrial Solutions AF-60 LP Micro Drive Operating Instructions - Manual (Page 34)

5.5 Examples
The following examples illustrate various Modbus RTU commands. If an error occurs, please refer to the Exception Codes section.
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) -
AF-60 LP™ Micro Drive Operating Instructions
DET-579A
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