Emerson Copeland CORESENSE, Technical Information

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D7.8.6/1112-0815/E 3/18
1 Introduction
Stream with CoreSense
™ Diagnostics provides advanced motor protection, diagnostics as well as Modbus®
communication. Modbus communication enables reading compressor operating and alarm information from
CoreSense both locally and remotely. By monitoring and analyzing data from the Copeland
™ compressor, the
module can accurately detect the cause of electrical and system related issues. If an unsafe condition is detected,
the module trips the compressor. A flashing LED indicator communicates an alert code and guides the service
technician more quickly and accurately to the root cause of a problem.
The module also has a RS-485 isolated communication port, by which the modules can communicate with the
system controller or the network master. The details of the communication are provided in this document.
1.1 Abbreviations
RTU

Remote Terminal Unit
DLT

Discharge Line Temperature
OAC

Overall Alarm Count (Total number of alarms since the module has been installed)
CRC

Cyclic Redundancy Check
CMD

Command
VFD

Variable Frequency Drive
1.1 Intent
This document defines the CoreSense Diagnostics module standard usage of the Modbus protocol specification.
This will allow 3rd party controllers to easily communicate to the CoreSense Diagnostics device using a standard
Modbus interface.
1.2 Scope
This document only defines the Modbus options that are used in Stream
with
CoreSense Diagnostics. It is not
intended to replace the Modbus protocol specification. This specification defines the common usage of the Physical
layer, Data Link layer and some parts of the Application layer interface.
1.3 References
For the details of the Modbus specification, refer to

Modicon Modbus Protocol Reference Guide PI
–MBUS–300 Rev. J

www.modbus.org
2 General description
Modbus uses a three-layer protocol:

Physical layer: the hardware interface;

Data Link layer: defines the reliable exchange of messages;

Application layer: defines message structures for the exchange of application specific information.
Modbus has some required features, some recommended features, and some optional features. This specification
starts with the physical layer and then works up to the application layer. The application layer defined in this
specification defines the standard Modbus memory map and data interchange.
Modbus is a protocol with a single master and multiple slave devices. The master device initiates all messages.