Table of Contents
Advertisement
Quick Links
FB-MODB Rev B
MODBUS COMMUNICATION
INSTRUCTIONS
Crest Models: 1.5 - 3.5
This manual must only be used
WARNING
by a qualifi ed 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.
Advertisement
Table of Contents
Troubleshooting
Subscribe to Our Youtube Channel
Related Manuals for Crest Audio 1.5
Summary of Contents for Crest Audio 1.5
- Page 1 FB-MODB Rev B MODBUS COMMUNICATION INSTRUCTIONS Crest Models: 1.5 - 3.5 This manual must only be used WARNING by a qualifi ed heating installer / service technician. Read instructions, including this manual, the Installation and Operation Manual, and the Service Manual, before installing.
-
Page 2: Table Of Contents
Contents 1. INTRODUCTION 3. MEMORY MAP Defi nitions ..............2 Primary Data Tables ............ . 7 Minimum System Requirements ........2 Crest Boiler Memory Map ..........7-8 2. CONFIGURATION Input Registers ............8 Addressing ..............3 Holding Registers ........... . 8 Timing Specifi... -
Page 3: Addressing
ModBus Instructions Introduction The ModBus communication board is equipped with a set of ten dip switches that are used to set the board confi guration (address, baud rate, and parity settings). The fi rst eight are used to set the address of each board. The ninth is used to set the baud rate. -
Page 4: Timing Specifi Cations
Lochinvar ModBus communication. Please ensure that Each message is started by at least 3.5 character times of the master device is transmitting ModBus RTU. silence. The maximum delay between frames is 1.5 character ModBus Board Diagnostics times. When the system temperature and/or tank temperature The ModBus board is equipped with three LED’s for visual... -
Page 5: Modbus Function Set
ModBus Instructions Confi guration (continued) ModBus Function Set Function Sub Function Description Read Coil Status Read Input Status Read Holding Registers Read Input Registers Force Single Coil Preset Single Register Read Exception Status Diagnostic - Return Query Data Diagnostic - Restart Communication Diagnostic - Return Diagnostic Register Diagnostic - Force Listen Mode Diagnostic - Clear Counters and Diagnostic... -
Page 6: Modbus Exception Codes
ModBus Instructions Confi guration 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 ILLEGAL FUNCTION devices, and was not implemented in the unit selected. -
Page 7: Memory Map Primary Data Tables
ModBus Instructions 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 Crest Boiler Memory Map Coils Address Description... -
Page 8: Crest Boiler Memory Map
ModBus Instructions Memory Map Crest Boiler Memory Map Input Registers Address Description Default Unit Min. Max. Resolution 30001 Discrete Inputs 1 - 16 65535 30002 Discrete Inputs 17 - 32 65535 30003 Discrete Inputs 33 - 48 65535 30004 System / Cascade Setpoint Degrees Celsius 30005 System Pump Speed In... -
Page 9: Wiring Requirements
ModBus Instructions Wiring Requirements Note that when the System Supply / System Return Figure 4-1_Terminal Strip Connections 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 fl uctuations in these temperatures. -
Page 10: Modbus
ModBus Instructions Wiring Requirements Figure 4-2_Control Inputs HWG THERMOSTAT / SENSOR ENABLING DEVICE CASCADE LOW VOLTAGE CONNECTION LOUVER PROVING SWITCH BOARD SYSTEM SENSOR - SUPPLY SYSTEM SENSOR - RETURN OUTDOOR SENSOR MODBUS BOARD SEQUENCER / BUILDING MANAGMENT SYSTEM AUX SWITCH 1 & 2 SMART CONTROL 0-10 INPUT FROM MODULE... -
Page 11: Modbus
ModBus Instructions Wiring Requirements (continued) Figure 4-3_Control Outputs 0-10V OUTPUT TO BOILER PUMP ALARM CONTACTS LOW VOLTAGE CONNECTION LOUVER RELAY BOARD RUN TIME CONTACTS BOILER RATE OUTPUT SEQUENCER / BUILDING MANAGMENT SYSTEM LINE VOLTAGE TERMINAL STRIP BOILER PUMP CONTACTOR SYSTEM PUMP CONTACTOR HWG PUMP CONTACTOR... -
Page 12: Typical Boiler System Wiring
ModBus Instructions Wiring Requirements Figure 4-4_Control Location MODBUS COMMUNICATION BOARD (MTR01) CONTROLLER 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... -
Page 13: Rs485
ModBus Instructions 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... -
Page 14: Unit Operation
ModBus Instructions Unit Operation Unit Operation with ModBus Communications To control a Crest boiler through a Building Management System communicating through ModBus, the Crest Demand Confi guration must be set to one of three options. These confi gurations allow different control points for a variety of applications. The confi... -
Page 15: Modbus
ModBus Instructions Unit Operation (continued) Demand Confi guration: ENABLE = ACTIVE; BMS = ACTIVE In this confi guration the unit is controlled by providing an enable signal. The setpoint command will be determined by the parameters in the control and a rate command through ModBus communications. The rate command will be 0 - 100% of modulation. -
Page 16: Modbus
ModBus Instructions 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 Crest 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 Defi... - Page 17 ModBus Instructions Unit Operation (continued) Rate and Temperature Conversions: For Example: Rate Send a setpoint of 110°F. When issuing a rate command the rate can be communicated The formula to use for the interpolation is: as percent modulation or a desired setpoint, depending on Rate Command = the setting of the BMS Type in the BMS Setup Menu.
-
Page 18: Troubleshooting
ModBus Instructions Troubleshooting Should you encounter problems communicating over Status Codes (Input Register 30014) ModBus, the following items should be checked in this order: 2 = Heat Demand blocked due to high absolute outlet Physical Layer temperature Communications Confi guration and Port Settings 3 = Heat Demand blocked due to high absolute fl... -
Page 19: Modbus
ModBus Instructions Troubleshooting (continued) Lockout Codes Description Analog to Digital converter input had changed too quickly Rapid Temperature Change on Pre-Mix Sensor 2 (S14) Rapid Temperature Change on Pre-Mix Sensor 1 (S13) Rapid Temperature Change on Pre-Mix Sensor 2 (S12) Rapid Temperature Change on Pre-Mix Sensor 1 (S11) Analog to Digital converter input is changed too quickly Rapid Temperature Change on Flue Sensor (S10) -
Page 20: Modbus
ModBus Instructions Troubleshooting Lockout Codes Description Outlet Sensor Short Outlet Sensor Open Internal Error Internal Error Parameters Programmed Error while programming Parameters Internal Error Pre-Mix Sensors Temperature Differential Too High Flame Failure 2 Small Fan Speed Low Small Fan Speed High Flame Failure 1 Ignition Failure Flue Damper Open... -
Page 21: Troubleshooting
ModBus Instructions Troubleshooting (continued) Installation / Replacement Procedure Figure 6-2_Control Panel w/MTR01 Control Board Turn OFF the main electrical power to the appliance. Turn OFF the main manual gas shutoff to the appliance. Unplug the three (3) wire harnesses on the MTR01 control board (see FIG. -
Page 22: Diagrams
ModBus Instructions Diagrams Figure 7-1 Ladder Diagram 120VAC NEUTRAL JUNCTION BOX BOX DEPICTS OPTIONAL ITEMS TERMINAL STRIP TERMINAL STRIP 120V SUPPLY "L" 120V SUPPLY "N" BOX DEPICTS DUAL SENSOR SINGLE HOUSING INTEGRATED CONTROL X1-3 1.5A EACH MAX ON/OFF LOW VOLTAGE SWITCH X1-12 TERMINAL STRIP... -
Page 23: Wiring Diagram
ModBus Instructions Diagrams (continued) Figure 7-2 Wiring Diagram BOX DEPICTS OPTIONAL ITEMS BOX DEPICTS DUAL SENSOR SINGLE HOUSING MODBUS BOARD X1-1 LARGE CONNECTION BOARD X1-2 LOW VOLTAGE X1-3 CN6-3 X6-3 120 VAC SHIELD INTEGRATED CONTROL CN6-2 X6-1 MODBUS HIGH VOLTAGE OPTION CN6-1 X6-2... -
Page 24: Revision Notes
Revision Notes: Revision A (ECO #C08179) initial release. Revision B (ECO C08542) refl ects edits made (pages 7, 8 and 18) due to changes made by SIT. FB-MODB Rev B 07/11...
Need help?
Do you have a question about the 1.5 and is the answer not in the manual?
Questions and answers