Function Code 06 - Preset Single Register - Honeywell HC900 User Manual

4.8 Function Code 06 - Preset Single Register

Description
Presets integer value into a single register (also refered to as 4X references).
The HC900 does not support Broadcast.
The registers that are specified in Section 6 with an access type "W" and integer and bit packed (16-bit
register) data types, can be written to via Function Code 06. Also, digital variables in 32-bit floating point
format can be written using this function code. Writing a non-zero value to either register of the digital
variable will result in a floating point 1 to be written to the variable. Writing a zero value to either register
will result in the variable being set to 0.
Query
The query message specifies the register references to be preset. Registers are addressed starting at zero:
Register 1 is addressed as 0.
Example: Set Rack #1, Loop #1 to Auto (address 00FAh) in the controller at slave address 1
TCP Example
RTU Example
Response
The normal response is an echo of the query returned after the register contents have been preset.
Example: Set Rack #1, Loop #1 to Auto (address 00FAh) in the controller at slave address 1.
TCP Example
RTU Example
Revision 13
April 2017
Query message format for function code 06
Slave Function Address
Address Code
(00 for TCP)
00 06
01 06
Response message format for function code 06
Slave Function Address
Address Code
(00 for TCP)
00 06
01 06
HC900 Process Controller Communications User Guide
Modbus/TCP & Modbus RTU Function Codes
Function Code 06 - Preset Single Register
Address Preset
High Low Data
High
00 FA 00
00 FA 00
Address Preset
High Low Data
High
00 FA 00
00 FA 00
Preset CRC CRC
Data (RTU) (RTU)
Low
01
01 CRC CRC
Preset CRC CRC
Data (RTU) (RTU)
Low
01
01 CRC CRC
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