Carrier WSHP Open v3 Integration Manual page 52

Appendix D: Johnson N2 Protocol Implementation Conformance Statement
Appendix D: Johnson N2 Protocol Implementation Conformance
Statement
Date: 11/12/2013
Vendor Name: Carrier
Product Names: WSHP Open
Product Model Number: Water Source Heat Pump
Protocol Description:
N2 is not a standard protocol, but one that was created by Johnson Controls, Inc. that has been made open and
available to the public. The speed of N2 network is limited to only 9600 baud. The N2 slave address can be set
from 01 to 99.
Product Description:
The WSHP Open is a factory-installed water source heat pump controller that is capable of speaking multiple
protocols. The WSHP Open controller speaks the Johnson N2 Open Protocol as described in the Metasys N2
System Protocol Specification (for Vendors) document, revision 6/13/96. Further details on the N2 supported
implementation are described below.
Communication Types:
2-wire EIA-485
Network Point Types:
Analog Inputs (AI)
Binary Inputs (BI)
Analog Outputs (AO)
Binary Outputs (BO)
Internal Floats (ADF)
Internal Integers (ADI)
Internal Bytes (BD)
Protocol Commands:
Identify Device Type
Sync Time
Poll Without Acknowledge
Poll With Acknowledge
Read Analog Input
Read Binary Input
Read Analog Output
Read Binary Output
Read Internal Parameter
Write Analog Input
Write Binary Input
Write Analog Output
WSHP Open v3
Integration Guide
Baud
Data Bits:
rates:
9600 8
48
Parity: Stop Bits:
None 1
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