SensorModbusMaster – EnviroDIY

This topic has 3 replies, 2 voices, and was last updated 2022-12-06 at 2:05 PM by Sara Damiano.

Viewing 3 reply threads

Author

Posts

2022-12-06 at 11:37 AM #17490

Participant

Hi, I am trying to use the library SensorModbusMaster. I have but some questions on the Git repository but have not received any answers.
<p dir=”auto”>I want to pull floating point data and trying to figure this out. My sensor simulator is set up for sensor address 1 and register 2 to send out floating point data on two registers, little endian. The debugging shows the response from the slave is right for decimal value 1000.5, reg 2 = 2000, reg 3 = 447A. But the answer from the function is “ovf” why am i not seeing 1000.5? Any help is appreciated.</p>
<p dir=”auto”>// —————————————————————————
// Include the base required libraries
// —————————————————————————
#include <Arduino.h>
#include <SensorModbusMaster.h></p>
<p dir=”auto”>// —————————————————————————
// Set up the sensor specific information
// ie, pin locations, addresses, calibrations and related settings
// —————————————————————————</p>
<p dir=”auto”>// Define the sensor’s modbus address
byte modbusAddress = 0x01; // The sensor’s modbus address, or SlaveID
long modbusBaudRate = 9600; // The baud rate the sensor uses</p>
<p dir=”auto”>// Define pin number variables
const int sensorPwrPin = -1; // The pin sending power to the sensor
const int adapterPwrPin = -1; // The pin sending power to the RS485 adapter
const int DEREPin = -1; // The pin controlling Recieve Enable and Driver Enable
// on the RS485 adapter, if applicable (else, -1)
// Setting HIGH enables the driver (arduino) to send text
// Setting LOW enables the receiver (sensor) to send text</p>
<p dir=”auto”>// Construct software serial object for Modbus
// This is just a assigning another name to the same port, for convienence
// Unless it is unavailable, always prefer hardware serial.
HardwareSerial* modbusSerial = &Serial1;</p>
<p dir=”auto”>// Construct the modbus instance
modbusMaster modbus;</p>
<p dir=”auto”>// —————————————————————————
// Main setup function
// —————————————————————————
void setup()
{
// Set various pins as needed
if (DEREPin >= -1)
{
pinMode(DEREPin, OUTPUT);
}
if (sensorPwrPin >= 0)
{
pinMode(sensorPwrPin, OUTPUT);
digitalWrite(sensorPwrPin, HIGH);
}
if (adapterPwrPin >= 0)
{
pinMode(adapterPwrPin, OUTPUT);
digitalWrite(adapterPwrPin, HIGH);
}</p>

&lt;code class="notranslate"&gt;// Turn on the "main" serial port for debugging via USB Serial Monitor
Serial.begin(9600);

// Turn on your modbus serial port
Serial1.begin(modbusBaudRate);
// ^^ use this for 8 data bits - no parity - 1 stop bits
// Despite being technically "non-compliant" with the modbus specifications
// 8N1 parity is very common.

// Turn on debugging, if desired
modbus.setDebugStream(&amp;Serial);

// Start the modbus instance
modbus.begin(modbusAddress, modbusSerial, DEREPin);

<code class="notranslate">// Turn on the "main" serial port for debugging via USB Serial Monitor

Serial.begin(9600);

// Turn on your modbus serial port

Serial1.begin(modbusBaudRate);

// ^^ use this for 8 data bits - no parity - 1 stop bits

// Despite being technically "non-compliant" with the modbus specifications

// 8N1 parity is very common.

// Turn on debugging, if desired

modbus.setDebugStream(&Serial);

// Start the modbus instance

modbus.begin(modbusAddress, modbusSerial, DEREPin);

</div>
<p dir=”auto”>}</p>
<p dir=”auto”>// —————————————————————————
// Main setup function
// —————————————————————————
void loop()
{
// Get data values from read-only input registers (0x04)
// Just for show, we will do the exact same thing 2 ways
// All values will be read as bigEndian</p>

&lt;code class="notranslate"&gt;// Some variables to hold results
//int16_t reg1 = 0;
<strong>float_t reg2 = 0.0;</strong>
//int16_t reg3 = 0;

// Method 1:
// Get three values one at a time from 3 different registers.
// This code is easier to follow, but it requires more back-and-forth between
// the Arduino and the sensor so it is a little "slower".
//reg1 = modbus.int16FromRegister(0x04, 0x01, bigEndian);
<strong>reg2 = modbus.float32FromRegister(0x04, 0x02, littleEndian);</strong>
//reg3 = modbus.int16FromRegister(0x04, 0x03, bigEndian);

// Print results
//Serial.print("reg1:");
//Serial.println(reg1);
Serial.print("reg2:");
Serial.println(reg2);
//Serial.print("reg3:");
//Serial.println(reg3);
//Serial.println();

<code class="notranslate">// Some variables to hold results

//int16_t reg1 = 0;

<strong>float_t reg2 = 0.0;</strong>

//int16_t reg3 = 0;

// Method 1:

// Get three values one at a time from 3 different registers.

// This code is easier to follow, but it requires more back-and-forth between

// the Arduino and the sensor so it is a little "slower".

//reg1 = modbus.int16FromRegister(0x04, 0x01, bigEndian);

<strong>reg2 = modbus.float32FromRegister(0x04, 0x02, littleEndian);</strong>

//reg3 = modbus.int16FromRegister(0x04, 0x03, bigEndian);

// Print results

//Serial.print("reg1:");

//Serial.println(reg1);

Serial.print("reg2:");

Serial.println(reg2);

//Serial.print("reg3:");

//Serial.println(reg3);

//Serial.println();

<div class=”zeroclipboard-container position-absolute right-0 top-0″></div>
</div>
<p dir=”auto”>} end main</p>
Monitor output =
<div>

Raw Request &gt;&gt;&gt; {0x01, 0x04, 0x00, 0x02, 0x00, 0x02, 0xD0, 0x0B}

1	Raw Request >>> {0x01, 0x04, 0x00, 0x02, 0x00, 0x02, 0xD0, 0x0B}

</div>
<div>

Raw Response (9 bytes) &lt;&lt;&lt; {0x01, 0x04, 0x04, 0x20, 0x00, 0x44, 0x7A, 0x42, 0xA7}

1	Raw Response (9 bytes) <<< {0x01, 0x04, 0x04, 0x20, 0x00, 0x44, 0x7A, 0x42, 0xA7}

</div>
<div>

reg2:ovf

reg2:ovf

</div>

2022-12-06 at 12:02 PM #17491
Chuck Weaver
Participant
BTW I am using a teensy 4.1 module

2022-12-06 at 12:09 PM #17492

Chuck Weaver

Participant

// ---------------------------------------------------------------------------
// Include the base required libraries
// ---------------------------------------------------------------------------
#include <Arduino.h>
#include <SensorModbusMaster.h>

// ---------------------------------------------------------------------------
// Set up the sensor specific information
//   ie, pin locations, addresses, calibrations and related settings
// ---------------------------------------------------------------------------

// Define the sensor's modbus address
byte modbusAddress = 0x01;   // The sensor's modbus address, or SlaveID
long modbusBaudRate = 9600; // The baud rate the sensor uses

// Define pin number variables
const int sensorPwrPin = -1;  // The pin sending power to the sensor
const int adapterPwrPin = -1; // The pin sending power to the RS485 adapter
const int DEREPin = -1;       // The pin controlling Recieve Enable and Driver Enable
                              // on the RS485 adapter, if applicable (else, -1)
                              // Setting HIGH enables the driver (arduino) to send text
                              // Setting LOW enables the receiver (sensor) to send text

// Construct software serial object for Modbus
// This is just a assigning another name to the same port, for convienence
// Unless it is unavailable, always prefer hardware serial.
HardwareSerial* modbusSerial = &Serial1;

// Construct the modbus instance
modbusMaster modbus;

// ---------------------------------------------------------------------------
// Main setup function
// ---------------------------------------------------------------------------
void setup()
{
    // Set various pins as needed
    if (DEREPin >= -1)
    {
        pinMode(DEREPin, OUTPUT);
    }
    if (sensorPwrPin >= 0)
    {
        pinMode(sensorPwrPin, OUTPUT);
        digitalWrite(sensorPwrPin, HIGH);
    }
    if (adapterPwrPin >= 0)
    {
        pinMode(adapterPwrPin, OUTPUT);
        digitalWrite(adapterPwrPin, HIGH);
    }

    // Turn on the "main" serial port for debugging via USB Serial Monitor
    Serial.begin(9600);

    // Turn on your modbus serial port
    Serial1.begin(modbusBaudRate);
    // ^^ use this for 8 data bits - no parity - 1 stop bits
    // Despite being technically "non-compliant" with the modbus specifications
    // 8N1 parity is very common.

    // Turn on debugging, if desired
    modbus.setDebugStream(&Serial);

    // Start the modbus instance
    modbus.begin(modbusAddress, modbusSerial, DEREPin);

}

// ---------------------------------------------------------------------------
// Main setup function
// ---------------------------------------------------------------------------
void loop()
{
    // Get data values from read-only input registers (0x04)
    // Just for show, we will do the exact same thing 2 ways
    // All values will be read as bigEndian

    // Some variables to hold results
    //int16_t reg1 = 0;
    //float_t reg2 = 0.0;
    //int16_t reg3 = 0;

    // Method 1:
    // Get three values one at a time from 3 different registers.
    // This code is easier to follow, but it requires more back-and-forth between
    // the Arduino and the sensor so it is a little "slower".
    //reg1 = modbus.int16FromRegister(0x04, 0x01, bigEndian);
   float reg2 = modbus.float32FromRegister(0x04, 0x02, littleEndian);
    //reg3 = modbus.int16FromRegister(0x04, 0x03, bigEndian);

    // Print results
    //Serial.print("reg1:");
    //Serial.println(reg1);
    Serial.print("reg2:");
    Serial.println(reg2);
    //Serial.print("reg3:");
    //Serial.println(reg3);
    //Serial.println();


}

100

101

102

// ---------------------------------------------------------------------------

// Include the base required libraries

// ---------------------------------------------------------------------------

#include <Arduino.h>

#include <SensorModbusMaster.h>

// ---------------------------------------------------------------------------

// Set up the sensor specific information

// ie, pin locations, addresses, calibrations and related settings

// ---------------------------------------------------------------------------

// Define the sensor's modbus address

byte modbusAddress = 0x01; // The sensor's modbus address, or SlaveID

long modbusBaudRate = 9600; // The baud rate the sensor uses

// Define pin number variables

const int sensorPwrPin = -1; // The pin sending power to the sensor

const int adapterPwrPin = -1; // The pin sending power to the RS485 adapter

const int DEREPin = -1; // The pin controlling Recieve Enable and Driver Enable

// on the RS485 adapter, if applicable (else, -1)

// Setting HIGH enables the driver (arduino) to send text

// Setting LOW enables the receiver (sensor) to send text

// Construct software serial object for Modbus

// This is just a assigning another name to the same port, for convienence

// Unless it is unavailable, always prefer hardware serial.

HardwareSerial* modbusSerial = &Serial1;

// Construct the modbus instance

modbusMaster modbus;

// ---------------------------------------------------------------------------

// Main setup function

// ---------------------------------------------------------------------------

void setup()

{

// Set various pins as needed

if (DEREPin >= -1)

{

pinMode(DEREPin, OUTPUT);

}

if (sensorPwrPin >= 0)

{

pinMode(sensorPwrPin, OUTPUT);

digitalWrite(sensorPwrPin, HIGH);

}

if (adapterPwrPin >= 0)

{

pinMode(adapterPwrPin, OUTPUT);

digitalWrite(adapterPwrPin, HIGH);

}

// Turn on the "main" serial port for debugging via USB Serial Monitor

Serial.begin(9600);

// Turn on your modbus serial port

Serial1.begin(modbusBaudRate);

// ^^ use this for 8 data bits - no parity - 1 stop bits

// Despite being technically "non-compliant" with the modbus specifications

// 8N1 parity is very common.

// Turn on debugging, if desired

modbus.setDebugStream(&Serial);

// Start the modbus instance

modbus.begin(modbusAddress, modbusSerial, DEREPin);

}

// ---------------------------------------------------------------------------

// Main setup function

// ---------------------------------------------------------------------------

void loop()

{

// Get data values from read-only input registers (0x04)

// Just for show, we will do the exact same thing 2 ways

// All values will be read as bigEndian

// Some variables to hold results

//int16_t reg1 = 0;

//float_t reg2 = 0.0;

//int16_t reg3 = 0;

// Method 1:

// Get three values one at a time from 3 different registers.

// This code is easier to follow, but it requires more back-and-forth between

// the Arduino and the sensor so it is a little "slower".

//reg1 = modbus.int16FromRegister(0x04, 0x01, bigEndian);

float reg2 = modbus.float32FromRegister(0x04, 0x02, littleEndian);

//reg3 = modbus.int16FromRegister(0x04, 0x03, bigEndian);

// Print results

//Serial.print("reg1:");

//Serial.println(reg1);

Serial.print("reg2:");

Serial.println(reg2);

//Serial.print("reg3:");

//Serial.println(reg3);

//Serial.println();

}

2022-12-06 at 2:05 PM #17493
Sara Damiano
Moderator
I also responded on GitHub (https://github.com/EnviroDIY/SensorModbusMaster/issues/25), but the endian-ness of your sensor simulator is not compatible. You simulator seems to be sending CDAB mixed-endian. SensorModbusMaster only supports ABCD or DCBA.