Modbus Protocol - York YVAG012 Operation & Maintenance Manual

MODBUS PROTOCOL

TABLE 15 - DEFINITIONS
NO. ITEM
1 Data Flow
2 Master - Slave
3 Temperature
4 Read/Write Mechanism
5 BAS Enable
6 Start/Stop Status
TABLE 16 – SYSTEM SETPOINTS
NO. Name
1 Chiller ON/OFF
2 Mode Setting
3 Cool Return WT Setpoint
4 Heat Return WT Setpoint
5 Cool Leaving WT Setpoint
6 Heat Leaving WT Setpoint
7 Low Sound Mode
8 Fault Reset
9 Cooling Control Select
10 Heating Control Select
11 Temperature Control Cycle
12 Water Temp. Control Diff.
JOHNSON CONTROLS
Cooke Industries - Phone: +64 9 579 2185
Communication Baud rate: 9600bps;
8-N-1: 1 start bit,1 stop bit, check bit-none, 8 data bits;
Modbus-RTU Protocol;
CRC: Cyclic Redundancy Check;
Hexadecimal data.
Modbus as master;
1# microboard as slave.
Unit: 0.1℃
Actual temperature=Register value/10
e.g.: Cooling LWT=81, then the actual temperature is 8.1℃
BAS need to keep communication with mainboard periodically;
BAS parameter setpoint may exceed unit default range and it is required for BAS to
read the setpoints from the mainboard.
The BAS Modbus addresses of subordinates are set through HMI;
Set DIP 301-7 to "ON" to make BAS enable.
Set the corresponding parameters in HMI to enable and disable the BAS Start/Stop
and Operating Mode functions.
The Start/Stop Command (Register value = 0) is only used to start/stop the unit;
Actual Start/Stop Status is accessible by reading Register value = 100.
Register
Function Code
Address
System Setpoints
3, 6, 16
3, 6, 16
3, 6, 16
3, 6, 16
3, 6, 16
3, 6, 16
3, 6, 16
3, 6, 16
3, 6, 16
3, 6, 16
3, 6, 16
3, 6, 16
Email: sales@cookeindustries.co.nz
FORM NO.: 6U5M-A11M-NB-EN
DESCRIPTION
Note
0 0-Invalid, 1-On, 2-Off
1 0-Cooling, 1-Heating, 8-Only Pump
2 10~30
3 25~50
4 5~25
5 30~55
7 1-Enabled
8 1-Reset
9 0-Fixed RT, 1-Fixed LT
10 0-Fixed RT, 1-Fixed LT
11 20~120, Unit: s
12 1~3
Web: www.cookeindustries.co.nz
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