GASSONIC Observer-i - 6.3.2. Modbus Read Response Message; 6.4. Modbus Write Command Protocol (Query;Response); 6.4.1. Modbus Write Query Message

GASSONIC OBSERVER-i
53
6.3.2. Modbus Read Response Message
Byte Modbus Range
Referenced to Gassonic
Observer-i
1
st
Slave
Address
1-247* (Decimal)
Gassonic Observer-i ID (Address)
2
nd
Function
Code
03 or 04 Read Holding Registers
3
rd
Byte Count 02 – FF (Hex) No. of Data Bytes
4
th
Data Hi 00-FF (Hex) Gassonic Observer-i Hi Byte
Status Data
5
th
Data Lo 00-FF (Hex) Gassonic Observer-i Lo Byte
Status Data
6
th
CRC Lo 00-FF (Hex) CRC Lo Byte
7
th
CRC Hi 00-FF (Hex) CRC Hi Byte
Table 7: Modbus Read Response Messages
NOTE: Address 0 is reserved for broadcast mode and will not be supported at this time.
6.4. Modbus Write Command Protocol (Query/Response)
6.4.1. Modbus Write Query Message
Byte Modbus Range
Referenced to Gassonic
Observer-i
1
st
Slave Address
1-247*
(Decimal)
Gassonic Observer-i ID (Address)
2
nd
Function Code 06 Preset Single Register
3
rd
Register Address
Hi**
00 Not used by Gassonic Observer-i
4
th
Register Address
Lo**
00-FF (Hex) Gassonic Observer-i Commands
5
th
Preset Data Hi 00-FF (Hex) Gassonic Observer-i Hi Byte
Command Data
6
th
Preset Data Lo 00-FF (Hex) Gassonic Observer-i Lo Byte
Command Data
7
th
CRC Lo 00-FF (Hex) CRC Lo Byte
8
th
CRC Hi 00-FF (Hex) CRC Hi Byte
Table 8: Modbus Write Query Message
NOTE*: Address 0 is reserved for broadcast mode and is not be supported at this time.
NOTE
**
: Start Address can be a maximum of 247 Address Locations (0000-0x00F7).