Appendix C: Modbus Protocol Implementation Conformance Statement
RTU Open v3 Carrier Proprietary and Confidential CARRIER CORPORATION ©2016
Integration Guide All rights reserved
47
Date: 11/12/2013
Vendor Name:
Product Names:
Product Model Number:
Protocol Description:
The RTU Open controller speaks the Modicon Modbus RTU/ASCII Protocol as described in the Modicon Modbus
Protocol Reference Guide, PI-MBUS-300 Rev.J. Further details on the Modbus implementation are described
below.
Product Description:
The RTU Open is a factory-installed rooftop controller that is capable of speaking multiple protocols.
Serial Transmission Mode:
38400, 76800
Used with Register
Numbers:
03 – Read Holding Registers
04 – Read Input Registers
Write Discrete Outputs (single)
06 – Preset Single Register
Write Holding Registers (single)
15 – Force Multiple Coils
16 – Preset Multiple Coils
Function Codes Used with this
Register Type:
Float Value (FLOAT)
Single-Precision IEEE floating point
value
3 – Read Holding Register
6 – Preset Single Register
16 – Preset Multiple Register
Appendix C: Modbus Protocol Implementation Conformance Statement