Data Aire DAP TM III. Metasys Control Points

Data Aire DAP TM III Metasys Control Points Data Aire, Inc. 230 West BlueRidge Avenue Orange, California 92865 Document Number 600-000-703 September 2009 Rev. 5.0 Document 600-000-703 Page 1 of 7

Table of Contents 1 Introduction...3 1.1 Scope...3 1.2 References...3 2 Metasys Control Point Definitions...3 3 Standby Operation Example...5 3.1 Querying the Standby Status...5 3.2 Setting the Standby Status...6 REVISION HISTORY Rev By Date Description 1 S. Johnson 4/20/07 Initial Release 2 S. Johnson 11/10/08 Added notes to bottom of table 3 S. Johnson 11/19/08 Added Section 3 4 S. Johnson 08/09/09 Added ADI 32 Fan Speed 5 S. Johnson 08/17/09 Fixed order of alarms Document 600-000-703 Page 2 of 7

1 Introduction 1.1 Scope This document describes the implementation of the point map for the Metasys protocol on the Data Air Processor III (DAP III). 1.2 References Metasys N2 System Protocol Specification (For Vendors), July 26, 1994. 2 Metasys Control Point Definitions Type Address Units Description Override ADF 1 Degree F Return Air Temperature No ADF 2 Percent R.H. Return Air Humidity No ADF 3 Degree F Discharge Air Temperature No ADF 4 Degree F High Temperature Last 24 Hours No ADF 5 Degree F Low Temperature Last 24 Hours No ADF 6 Percent R.H. High Humidity Last 24 Hours No ADF 7 Percent R.H. Low Humidity Last 24 Hours No ADF 8 Degree F Temperature Deadband Yes ADF 9 Percent R.H. Humidity Deadband Yes ADF 10 Degree F Chilled Water Temperature No BI 1 Note 1 Compressor Short Cycle Alarm No BI 2 Note 1 Custom Alarm 1 No BI 3 Note 1 Custom Alarm 2 No BI 4 Note 1 Custom Alarm 3 No BI 5 Note 1 Custom Alarm 4 No BI 6 Note 1 Dirty Filter Alarm No BI 7 Note 1 Discharge Sensor Problem Alarm No BI 8 Note 1 Fan Overload Alarm No BI 9 Note 1 Fire Detected Alarm No BI 10 Note 1 High Humidity Warning No BI 11 Note 1 High Pressure C1 Alarm No BI 12 Note 1 High Pressure C2 Alarm No BI 13 Note 1 High Temperature Warning No BI 14 Note 1 Humidifier Problem Alarm No BI 15 Note 1 Humidity Sensor Problem Alarm No BI 16 Note 1 Local Alarm 1 No Document 600-000-703 Page 3 of 7

Type Address Units Description Override BI 17 Note 1 Local Alarm 2 No BI 18 Note 1 Local Alarm 3 No BI 19 Note 1 Local Alarm 4 No BI 20 Note 1 Low Humidity Warning No BI 21 Note 1 Low Pressure C1 Alarm No BI 22 Note 1 Low Pressure C2 Alarm No BI 23 Note 1 Low Temperature Warning No BI 24 Note 1 Low Voltage Alarm No BI 25 Note 1 Maintenance Due Alarm No BI 26 Note 1 Manual Override Alarm No BI 27 Note 1 No Air Flow Alarm No BI 28 Note 1 No Water Flow Alarm No BI 29 Note 1 Power Problem Alarm No BI 30 Note 1 Smoke Detector Alarm No BI 31 Note 1 Standby Pump On Alarm No BI 32 Note 1 Temperature Sensor Problem Alarm No BI 33 Note 1 UPS Power On Alarm No BI 34 Note 1 Water Under Floor Alarm No BI 35 Note 1 Humidification Inhibited No BI 36 Note 1 Reheat Inhibited No BI 37 Note 1 Reheat And Humid Inhibited No BI 38 Note 1 Low Discharge Alarm No BI 39 Note 1 High Condensate Alarm No BI 40 Note 1 Unit In Standby Held Off No AO 1 Percent Open Chilled Water Valve Position No ADI 1 Hours Blower Runtime No ADI 2 Hours Condenser Runtime No ADI 3 Hours Compressor 1 Runtime No ADI 4 Hours Compressor 2 Runtime No ADI 5 Hours Compressor 3 Runtime No ADI 6 Hours Compressor 4 Runtime No ADI 7 Hours Heater 1 Runtime No ADI 8 Hours Heater 2 Runtime No ADI 9 Hours Heater 3 Runtime No ADI 10 Hours Humidifier Runtime No ADI 11 Hours Dehumidification Runtime No ADI 12 Hours Energy Saver Runtime No ADI 13 Hours Chilled Water Runtime No ADI 14 Percent Cooling Utilization Last Hour No ADI 15 Percent Heating Utilization Last Hour No ADI 16 Percent Chilled Water Utilization Last Hour No ADI 17 Percent Humidifier Utilization Last Hour No ADI 18 Degree F Fire Detect Limit Yes ADI 19 Degree F Low Return Air Temperature Limit Yes Document 600-000-703 Page 4 of 7

Type Address Units Description Override ADI 20 F High Return Air Temperature Limit Yes ADI 21 Percent R.H. Low Humidity Alarm Limit Yes ADI 22 Percent R.H. High Humidity Alarm Limit Yes ADI 23 Degree F Low Discharge Air Temperature Limit Yes ADI 24 Degree F Chilled Water Available Limit Yes ADI 25 Degree F Temperature Setpoint Yes ADI 26 Percent R.H. Humidity Setpoint Yes ADI 27 Note 1 Unit Standby Status Yes ADI 28 Note 2 Humidification Status No ADI 29 Cooling Stages On No ADI 30 Heating Stages On No ADI 31 Note 1 Energy Saver Status No ADI 32 Percent Fan Speed Yes Note 1: Note 2: Note 3: For the control points indicated, a value of 0 means that the described status or alarm condition is not present. A value of 1 means that the described status or alarm condition is present. The humidification status is encoded as follows: 0 means neither humidifying nor dehumidifying. 1 means dehumidifying. 2 means humidifying. The Override column indicates which of the points can be changed using the 0x72 override command. Points marked No cannot be changed. Those which are marked Yes can be changed with the 0x72 override command. Note that the complete N2 override mechanism is not implemented. In particular, we do not save away a local value when a point is overridden, we do not set the override active bit in the Object Status byte, and we do not support the override release commands. 3 Standby Operation Example There are three relevant command sequences associated with the Metasys Standby operation. These are putting a DAP III into standby and taking a DAP III out of standby. 3.1 Querying the Standby Status The standby control point Unit Standby Status is a point of type ADI with a point address of 27. The ADI points are Internal Integer Parameters. By reference to the N2 System Protocol Specification, it can be determined that to read this point you must construct a message with the following structure: > Start of message Document 600-000-703 Page 5 of 7

01 Address of unit ID #1 1 Read internal parameter command 6 Read from region 6 (Internal Integer Parameters) 1A Object number (hex value of object number 27) 02 Attribute number (current value) 9C Checksum When this message is sent to the DAP III during normal operation it will reply with: A00000020<CR> This is interpreted as: A Start of message 00 Object Status (attribute 1) 0000 Current Value (attribute 2) A value of 0000 means normal operation 20 Checksum When this message is sent to the DAP III during standby operation it will reply with: A00000121<CR> This is interpreted as: A Start of message 00 Object Status (attribute 1) 0001 Current Value (attribute 2) A value of 0001 means standby 21 Checksum 3.2 Setting the Standby Status To change the Metasys standby status of a DAP III to standby operation, construct the following command. (Refer to the Metasys N2 System Protocol Specification section Override Internal Parameter Command for more information.) > Start of message 01 Address of unit ID #1 7 Override internal parameter command 2 Override subcommand 06 Region (DAP III internal integer parameters) 1A Object number (hex value of object number 27) 0001 New parameter value (0001 means go to standby mode) 63 Checksum DAP III unit will reply with A and enter standby operation. Document 600-000-703 Page 6 of 7

To change the Metasys standby status of a DAP III from standby operation to normal on (controlling) operation, construct the following command: > Start of message 01 Address of unit ID #1 7 Override internal parameter command 2 Override subcommand 06 Region (DAP III internal integer parameters) 1A Object number (hex value of object number 27) 0000 New parameter value (0001 means go to standby mode) 62 Checksum DAP III unit will reply with A and enter normal operation. Document 600-000-703 Page 7 of 7