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SYNC-MODB Rev A
MODBUS COMMUNICATION
INSTRUCTIONS
SYNC Models: 1.0 - 1.3 - 1.5
This manual must only be used by a
WARNING
qualified heating installer / service
technician. Read all instructions,
including this manual, the
Installation and Operation Manual,
and the Service Manual, before
installing. Perform steps in the
order given. Failure to comply could
result in severe personal injury,
death, or substantial property
damage.
Save this manual for future reference.
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Contents 1. INTRODUCTION 3. MEMORY MAP Definitions .................................................................... 2 Primary Data Tables.....................................................7 Minimum System Requirements .................................. 2 SYNC Boiler Memory Map...........................................7-8 2. CONFIGURATION Input Registers .......................................................8 Addressing ................................................................... 3
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Modbus Instructions 2 Configuration The Modbus communication board is equipped with a set of ten dip switches that are used to set the board configuration (address, baud rate, and parity settings). The first eight are used to set the address of each board. The ninth baud rate. The tenth is parity. Figure 2-1_Modbus Communication Board DIP SWITCHES LED’S Addressing Example: The Modbus addressing space is comprised of 256 different addresss. To set the address of the Modbus board to 50, dip sw
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Modbus Instructions 2 Configuration Timing Specifications Data Transmission Mode The baud rate for the Modbus board is selectable with Dip Many Modbus bus master devices can be configured to transmit switch #9. data in either Modbus RTU or Modbus ASCII modes. Since RTU messages can be formatted to use fewer data bits and are 1 = 19200 bps therefore more efficient, RTU has been chosen to be used with 0 = 9600 bps all Lochinvar Modbus communication. Please ensure that the Each message is starte
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Modbus Instructions 2 Configuration (continued) Modbus Function Set Function Sub Function HEX Description Dec HEX Dec 1 01 Read Coil Status 2 02 Read Input Status 3 03 Read Holding Registers 4 04 Read Input Registers 5 05 Force Single Coil 6 06 Preset Single Register 7 07 Read Exception Status 8 08 0 00 Diagnostic - Return Query Data 1 01 Diagnostic - Restart Communication 2 02 Diagnostic - Return Diagnostic Register 4 04 Diagnostic - Force Listen Mode Diagnostic - Clear Counters and Diagnostic
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Modbus Instructions 2 Configuration Modbus Exception Codes MODBUS Exception Codes Code Name Meaning The function code received in the query is not an allowable action for the server (or slave). This may be because the function code is only applicable to newer 01 ILLEGAL FUNCTION devices, and was not implemented in the unit selected. It could also indicate that the server (or slave) is in the wrong state to process a request of this type, for example because it is unconfigured and is being as
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Modbus Instructions 3 Memory Map Primary Data Tables Table Data Type Read / Write Discrete Inputs Single Bit Read Only Coils Single Bit Read / Write Input Registers 16-Bit Word Read Only Holding Registers 16 Bit Word Read / Write SYNC Boiler Memory Map Coils Address Description Default Unit Min. Max. Resolution 00001 Boiler Enable / Room Thermostat 1 / Stage 1 0 1=ON / 0=OFF 0 1 1 00005 Tank Thermostat 0 1=ON / 0=OFF 0 1 1 Discrete Inputs 10001 Manual Reset High Limit 1 0 1=ON / 0=OFF 0 1 1 100
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Modbus Instructions 3 Memory Map SYNC Boiler Memory Map Input Registers Address Description Default Unit Min. Max. Resolution 30001 Discrete Inputs 1 - 16 0 NA 0 65535 1 30002 Discrete Inputs 17 - 32 0 NA 0 65535 1 30003 Discrete Inputs 33 - 48 0 NA 0 65535 1 30004 System / Cascade Setpoint 0 Degrees Celsius 0 130 0,5 30006 Cascade Total Power 0 % 100 800 1 30007 Cascade Current Power 0 % 0 800 1 30008 Outlet Setpoint 1 0 Degrees Celsius 0 130 0,5 30009 Outlet Temperature 1 0 Degrees Celsius 0
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Modbus Instructions 4 Wiring Requirements Note that when the System Supply Temperature and/or the Tank Temperature are provided by the BAS, they need to be refreshed every few seconds. This is required in order to prevent unwanted fluctuations in these temperatures. If these values are not provided every few seconds (timeout is programmable), the boiler will revert to its own internal control. If neither of these temperatures is provided by the BAS, but any of the other control signals are b
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Modbus Instructions 4 Wiring Requirements Figure 4-2_Control Inputs SECONDARY SMART TOUCH LOW VOLTAGE CONNECTION CONTROL MODULE BOARD PRIMARY SMART TOUCH CONTROL MODULE SEQUENCER / BUILDING MANAGEMENT SYSTEM OUTDOOR SENSOR HW TANK SENSOR HEAT EXCHANGER 1 / HEAT EXCHANGER 2 INLET TEMPERATURE SENSOR SYSTEM SENSOR HEAT EXCHANGER 1 / FLOW SWITCH HEAT EXCHANGER 2 OUTLET TEMPERATURE SENSOR BLOCKED DRAIN SWITCH HW THERMOSTAT HEAT EXCHANGER 1 / HEAT EXCHANGER 2 FLUE GAS SENSOR ROOM THERMOSTAT / LO
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Modbus Instructions 4 Wiring Requirements (continued) Figure 4-3_Control Outputs SECONDARY SMART TOUCH LOW VOLTAGE CONNECTION CONTROL MODULE BOARD PRIMARY SMART TOUCH CONTROL MODULE ALARM BELL RUN TIME CONTACTS HEAT EXCHANGER 1 / HEAT EXCHANGER 2 BOILER PUMP SEQUENCER / BUILDING SYSTEM PUMP MANAGEMENT SYSTEM TOUCH PANEL HW PUMP TOUCH DISPLAY INTERFACE IGNITOR PC INTERFACE BLOWER GAS VALVE 11
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Modbus Instructions 4 Wiring Requirements Figure 4-4_Control Location CONTROLLER 2 CONTROLLER 1 MODBUS COMMUNICATION BOARD (MTR01) HEAT EXCHANGER 1 HEAT EXCHANGER 2 Typical Boiler System Wiring Physical Configuration: Cascade without Individual Monitoring Modbus RS485 Port on Gateway or Building System Modbus RS485 Communication Bus Cascade Daisy Chain Connection 12
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Modbus Instructions 4 Wiring Requirements (continued) Physical Configuration: Cascade with individual Monitoring Modbus RS485 Port on Gateway or Building System Modbus RS485 Communication Bus Cascade Daisy Chain Connection Physical Configuration: Direct Control Modbus RS485 Port on Gateway or Building System Modbus RS485 Communication Bus 13
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Modbus Instructions 5 Unit Operation Unit Operation with Modbus Communications To control a SYNC boiler through a Building Management System communicating through Modbus, the SYNC Demand Configuration must be set to a value of 4, 5, or 6. These configurations allow different control points for a variety of applications. The configuration can be set by selecting Main>>Setup>>Service/Setup>>Demand Config. Figure 5-1_Setup Screen The SYNC boiler is equipped with a Modbus communication timer. Thi
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Modbus Instructions 5 Unit Operation (continued) Demand Configuration 5 In this configuration the unit is controlled by providing an enable signal and a rate command through Modbus communications. The rate command will be 0 - 100% of modulation. All sensors and limiting devices should be hardwired to the terminal strip on the back of the unit excluding the thermostat enable and tank thermostat enable signal. These signals will be sent to the unit via Modbus. The holding registers will need to
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Modbus Instructions 5 Unit Operation DHW with remote control: This installation may or may not have the hot water generator in close proximity to the boiler. Its sensors and thermostat values are only available through the Modbus communication bus. To ensure that the SYNC boiler can properly respond to a call for hot water generation the following holding registers must be set in addition to other commands: Holding Registers Definition Bit Value (HEX) Action 40001 Configuration 00 4A Set Confi
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Modbus Instructions 5 Unit Operation (continued) Rate and Temperature Conversions: For Example: Send a setpoint of 110°F. Rate The formula to use for the interpolation is: When issuing a rate command the rate can be communicated as percent modulation or a desired setpoint, depending on the Rate Command = setting of the BMS Type in the BMS Setup Menu. (Desired Setpoint – BMS Temp at Low Analog Input) (High The proper data format for the modulation percentage is the Voltage-Low Voltage) + Low Vo
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Modbus Instructions 6 Troubleshooting Should you encounter problems communicating over Status Codes (Input Registers 30014 and 30023) Modbus, the following items should be checked in this order: 2 = Heat Demand blocked due to high absolute outlet 1. Physical Layer temperature 2. Communications Configuration and Port Settings 3 = Heat Demand blocked due to high absolute flue 3. Modbus Error Codes temperature 4. Unit Status / Blocking / Lockout Codes 4 = Heat Demand blocked due to high absolut
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Modbus Instructions 6 Troubleshooting (continued) 1. Turn OFF the main electrical power to the appliance. Lockout Codes (Input Registers 30016 and 30025) 2. Turn OFF the main manual gas shutoff to the appliance. 161 = EEPROM code Parameters not Re-Programmed by Lochinvar 3. Unplug the three (3) wire harnesses on the MTR01 control 164 = EEPROM code No Reset Allowed (> 15 minutes) board (see FIG. 6-1). 166 = EEPROM code Auto Reset High Limit 4. Unscrew the four (4) mounting nuts on the MTR01 co
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Modbus Instructions 7 Diagrams Figure 7-1 Ladder Diagram_Part 1 BOX DEPICTS OPTIONAL ITEMS LOW VOLTAGE 120 VAC HIGH VOLTAGE CONTROL CONTROL MODULE 1 MODULE 2 LOUVER RELAY 1 X8 X6-8 X8 X5 X5- -7 7 X5-7 24V 24V LOUVER X5-4 RELAY 2 X5-4 FLAP AIR PRESSURE FLAP AIR PRESSURE VALVE SWITCH VALVE SWITCH X5-14 X5-14 HI-LIMIT HI-LIMIT X6-8 X5-8 INLET INLET X5-8 SENSOR SENSOR X5-1 X5-1 OUTLET OUTLET X5-9 X5-9 SENSOR SENSOR X5-2 X5-2 FLUE FLUE SENSOR SENSOR X5-3 X5-3 BLOCKED DRAIN AUTO RESET AUTO RESET X5-
