#Modbus float format 32 bit#

Yes, I suspect for low values you may well get the SCADA to read some values, though you would need to make that unsigned 16 bits. Using an union is probably the suggested method, otherwise you can do it with pointers, by pointing to the high order 16 bits of the float and then the low order 16 bits placing each into a holding register. I use the INA226, with higher bus voltage capabilities, with this library: GitHub You can look inside that library and see how it works and pull it apart if you wish, or just address the chip itself and get the data directly, they are quite nice chips. The library is giving you the float data, not the chip itself.

#Modbus float format 32 bit#

Then, the SCADA system needs to know to read in the two holding registers and interpret back to 32 bit float.ДЄnother method, and the way I would do this is to not use the library you are using, but instead to know and understand the INA219 type of sensor. There are a few ways in which you can do this in code. What you need to do is to place half of the 32 bit float in one holding register and the other half of the 32 bit float in another holding register. Mb.MbData = current_mA //Here is the problemYou are attempting to place 32 bits of float data into 16 bits of uint16_t. Remember all Modbus holding registers are 16 bits of unsigned data. Mb.MbData = Current_int //mA can reach 3200, so 3200*100 overflows this data type Mb.MbData = current_mA //Here is the problem 9.40mA * 100 = 940 / In the master I just scale it. Loadvoltage = busvoltage + (shuntvoltage / 1000) Д¬urrent_int = current_mA * 100 //This shifts the decimal point 2 places to the right Shuntvoltage = ina219.getShuntVoltage_mV() So I will be testingвЂ¦ Mb.MbData,Mb.MbData = 30.11 as soon as I get home today. Register 40108 could also be combined with 40109 to form any of these 32-bit data types:ДЄ 32-bit unsigned integer (a number between 0 and 4,294,967,295) It works, but not if the current is a negative number.ДЇrom the Simply Modbus website - Here gives example likeвЂ¦ So what I do is multiply by 100 and then send the int over modbus, in the master I do linear scaling. I tried using low byte en high byte from here but does not work. So I need to write the value to two 16bit registers. What I want to do is read the current sensor through modbus. Д®verything is setup and I can read any register from the Arduino and control holding registers adjust set points. I have ethernet shield and modbus library for Arduino - Modbus. These seem to be taken together as 0x43802666 as the bit pattern for 32-bit float.I tried reading this thread THIS but I can not for the life of me figure out how it is do be done. So, your values of 172 are two halves of a 32-bit floating point number. Your voltage from phase two to neutral appears to be encoded into two consecutive 16-bit registers, which is a somewhat normal scheme for conveying 32bit floats via MODBUS, from what I can tell. Your MODBUS map shows V2N at 30002, and you notice 30003 is not mentioned in the map. I'm not sure this can really be considered topical, but someone wanting to read floating point numbers over MODBUS with an Arduino might get something out of it. Serial.println(node.getResponseBuffer(0x08)) Serial.println(node.getResponseBuffer(0x07)) Serial.println(node.getResponseBuffer(0x06)) Serial.println(node.getResponseBuffer(0x05)) Serial.println(node.getResponseBuffer(0x04)) Serial.println(node.getResponseBuffer(0x03)) Serial.println(node.getResponseBuffer(0x02)) Serial.println(node.getResponseBuffer(0x01)) Result = node.readInputRegisters(0x30000, 10) Callbacks allow us to configure the RS485 transceiver correctly Modbus communication runs at 9600 baud am able to get the raw data from the instrument but data structure seems to be in decimal format, can someone help me to convert this into float.thank you #include Hi,am trying to communicate with power-factor controller using modbus RTU,am following example sketch from modbusmaster library.