Modbus Read Response Message; Modbus Write Command Protocol (Query/Response); Modbus Write Query Message; Modbus Write Response Message - MSA FL500 Operating Manual

Modbus Interface
1.3.2

Modbus Read Response Message

Byte
1
2
3
4
5
6
7
*Address 0 is used for broadcast mode and is not supported at this time.
1.4.

Modbus Write Command Protocol (Query/Response)

1.4.1

Modbus Write Query Message

Byte Modbus Query
1 Slave Address
2 Function Code
3 Register Address Hi**
4 Register Address Lo**
5 Preset Data Hi
6 Preset Data Lo
7 CRC Lo
8 CRC Hi
*Address 0 is used for broadcast mode and is not supported at this time.
**Starting Address can be a maximum of 247 address locations (0000 to 0x00F7).
US
1.4.2

Modbus Write Response Message

Byte Modbus Query
1 Slave Address
2 Function Code
3 Register Address Hi**
4 Register Address Lo**
5 Preset Data Hi
6 Preset Data Lo
7 CRC Lo
8 CRC Hi
*Address 0 is reserved for broadcast mode and is not supported at this time.
**Starting Address can be a maximum of 247 address locations (0000 to 0x00F7).
6
Modbus Query Range
Slave Address 1 - 247* (Decimal)
Function Code 03 or 04
Byte Count 02 - FF (Hex)
Data Hi 00-FF (Hex)
Data Lo 00-FF (Hex)
CRC Lo 00-FF (Hex)
CRC Hi 00-FF (Hex)
FL500 Modbus Communication Operating Manual
Range
1 - 247* (Decimal)
06
00
00-FF (Hex)
00-FF (Hex)
00-FF (Hex)
00-FF (Hex)
00-FF (Hex)
Range FL500 Response
1 - 247* (Decimal) FL500 ID (address)
06 Preset single register
00 Not used
00-FF (Hex) FL500 commands
00-FF (Hex) FL500 Hi byte command data
00-FF (Hex) FL500 Lo byte command data
00-FF (Hex) CRC Lo byte
00-FF (Hex) CRC Hi byte
FL500 Response
FL500 ID (address)
Read Holding registers
Number of data bytes
FL500 Hi byte status data
FL500 Lo byte status data
CRC Lo byte
CRC Hi byte
FL500 Response
FL500 ID (address)
Preset single register
Not used
FL500 commands
FL500 Hi byte command data
FL500 Lo byte command data
CRC Lo byte
CRC Hi byte