The M-Bus ("Meter-Bus") is a standard for remote reading of meters. It is usable for most types of consumption meters as well as for various sensors and actuators. The GW-7828 is specially designed for M-Bus slave device. It offers Modbus RTU communication by three kinds of interface, RS-232, RS-422 and RS-485.
2.1 LED Indicator The GW-7828 module provides three LED indicators, including indicators for power status and module status. The Following is an overview of the purpose and function of each LED indicator together with a description. LED Name LED Description...
2.2 Rotary Switch The GW-7828 module provides two rotary switches that are used to change UART Baud Rate and M-Bus Baud Rate. The following is an overview of the purpose and function of each rotary switch position together with a description.
The DIP switch is used to update firmware and configure M-Bus Meter setting. The functions of each mode will be explained in detail in later chapters. After changing the configuration of the DIP switch, the GW-7828 needs to reboot to enable the new setting. Init Pin...
The figure below is an illustration of module wiring. Connect the PC COM port to the RS-232 port and connect M-Bus meter to M-Bus port of the GW-7828. Set the DIP switch to the configuration mode and then power it on.
Execute the M-Bus utility. There will be a connection diagram as first. Click “Configure” tab page, choose the corresponding COM port in PC then click “Connect” button to connect with module. Please be noted that the UART baud rate of GW-7828 will be 115200bps when it is in configuration Mode.
The first page of the utility lists baud rate and data format configuration of the serial port and the M-Bus port and it also shows the Modbus RTU node ID of the GW-7828. User could add a new baud rate and data format setting as need in this page.
In the “Meter” page of the utility, user could configure the M-Bus communication setting by using “Import” or “Add” functions. The usages of these functions are listed as following sections. GW-7828 (Modbus RTU Slave to MBus Master Gateway) User Manual Version 1.00 Page:15...
3.3.1 Import There are two ways to add M-Bus Meter setting into GW-7828. One is using “Import” to import an existed configuration file and save to GW-7828. The configure steps are as following: Step1: Press “Import” button. Step2: Open an existed configuration file of XML format.
User could export the existed module configuration to a XML file by the “Export” function. Step1: Press “Export” button. Then select path and input file name to export the configuration. GW-7828 (Modbus RTU Slave to MBus Master Gateway) User Manual Version 1.00 Page:18...
3.3.3 Add The second way to add meter configuration to GW-7828 is using “Add” function. The “Add” function can add meter of EN-13757 protocol or CJ/T-188 protocol into GW-7828. Refer below operation example for detail setting step. Step1: Press “Add” button and select the protocol of the meter. There are two protocols, EN-13757 and CJ/T188 for select.
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Step3: Confirm to delete meter which is selected. Step4: it will show the meter information after deleting as below. Step5: After delete meter configuration completely, press “Save” to save change to GW-7828. GW-7828 (Modbus RTU Slave to MBus Master Gateway) User Manual Version 1.00...
The “Value” field records value type of meters’ data. It will show the value type of meters’ data according to the definition in EN-13757 protocol or CJ/T-188 protocol. GW-7828 (Modbus RTU Slave to MBus Master Gateway) User Manual Version 1.00 Page:32...
The “Cycle” field records the minimum cycle time (unit is sec.) for polling all meters’ data. Please be noted that the cycle time parameter is for all meters of the M-Bus network. GW-7828 (Modbus RTU Slave to MBus Master Gateway) User Manual Version 1.00 Page:34...
The “ Description” field records meaning of meters’ data. It will show the real meaning of meters’ data according to the definition in EN-13757 protocol or CJ/T-188 protocol. GW-7828 (Modbus RTU Slave to MBus Master Gateway) User Manual Version 1.00 Page:35...
The “Register” field records the total word count and the Modbus address of every data at GW-7828. Take the below as an example, this is a water meter (Medium) of EN-13757 protocol (Protocol) with serial number 10153802 (Serial). It has total 4 words data length (Register) and data is 8 digit BCD type (Value) from Modbus address 0x0000 ~ 0x0001 (Register) and 2 data is also 8 digit BCD type (Value) from Modbus address 0x0002 ~ 0x0003 (Register).
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Appendix A. Firmware Update The firmware on the GW-7828 module can be updated via COM Port. The latest firmware file (*.fw file) and the latest version of the firmware update utility (FW_Update_Tool.zip) are available from the web link below. A notification will not be sent when a new version is released.