Video Description

In this video, we will demonstrate how to set up communication for several types of sensors, as well as the settings you can use to customize your sensor for your application.

Video Content

Thank you for choosing Automation Products Group for your sensor and monitoring needs. If you’ve purchased an RS-485 sensor from Automation Products Group, you already know that the versatility and convenience of sensor interface communication is invaluable in a world of increasingly automated industries. The ability to monitor and log readings, and alter sensor settings from a network location, saves both time and money.

00:22 APG MODBUS IS THE HUB FOR RS-485 COMMUNICATION
APG Modbus is the hub for RS-485 communication with your sensors. Using APG Modbus, you can change everything from communication baud rate to the custom labels for your sensors.

00:45 THIS VIDEO
In this video, we will demonstrate how to set up communication for several types of sensors, as well as the settings you can use to customize your sensor for your application.

00:51 PRODUCTS WITH RS-485 COMMUNICATION
To communicate with APG Modbus, several APG products such as the RST interface series or DCR-1006A are available with RS-485 communication. The RST-4100 is designed for use with an MPX sensor with Hart communication. There are also a variety of other RS-485 USB adapters available from other manufacturers.

01:28 CHECK YOUR SENSOR WIRING INFORMATION
To begin, check your sensor wiring information and wire the sensor to your RS-485 communication device according to the A-B wiring configuration.

01:40 POWER YOUR SENSOR
Your sensor will also need to be powered in order to operate. This can be done with an external power supply or, in the case of a DCR-1006A, with the included 24-volt power line.

01:55 MPX WIRING NOTE
Please note that if you are wiring an MPX, a 120-ohm resistor must be installed between the A and B terminals of the sensor. If you are wiring multiple MPX sensors in a daisy chain, the resistor must be placed between the A and B terminals of the last sensor in the chain. If you are using a communication device other than an RST-6001, a 120-ohm resistor must also be installed between the A and B terminals of the RS-485 device.

The RST-6001 has this resistor installed internally. If you are programming an MPX with 4-20 milliamp output, a 150 to 700-ohm load resistor must be installed in series between the RST and the positive power terminal.

Upon opening APG Modbus, you will first need to set up your communication based on the sensor you are using.
  1. Open the Configure tab and select Communication.
  2. On the right side of the Communication Configuration menu, select your sensor type from the drop-down menu.

03:11 ASSIGNING NEW ADDRESS TO SENSOR
You can also change the number of sensors, as well as assign a new address number to a sensor. The default sensor address for APG sensors is 1.If you need to change the sensor address number, don’t do it yet! The number will first need to be changed in the sensor parameters.

On the left side of the menu, you can change your communication options. Choose between USB or Comm port and select your serial setup options. 9600 baud rate with no parity and 1 stop bit is standard for APG sensors.

Please note that MPX sensors can only communicate at a baud rate of 9600.

APG recommends contacting the factory before changing any communication settings to ensure compatibility with your device.

Be sure to click “Save configuration” after any changes made to this screen.

Once your communication configuration is complete, return to the main screen and click the Start Communication button.

The parameter screen should update with all parameters received from the sensor highlighted in green, and the sensor description should read Comm Good. If the parameter screen does not update or is flashing Comm Bad, check your wiring and sensor address.

04:18 COMMUNICATION FOR MULTIPLE SENSORS
If you are setting up communication for more than one sensor, open the Help tab and select Quick Start for instructions on how to do this.

04:56 SETTING UP PARAMETERS FOR YOUR APPLICATION
With communication open between the sensor and APG Modbus, you are ready to setup parameters for your application. Exact parameters will vary depending on the type of sensor being used. Reference the parameter descriptions in APG Modbus and your sensor instruction manual to determine what values and corresponding parameters need to be changed.

  1. To change a parameter, find the entry you want to change in the “Description” column.
  2. Change the number in the “Value” column and click “Send”. The register row should blue, showing parameters being successfully sent to the sensor.
  3. To change your sensor address number, change the Sensor Address parameter and click the “Send” button. The register will turn blue as the parameter is sent but will then turn yellow and the status will change to Comm Bad. This is because the program is still trying to communicate with the old sensor number. To fix this, return to the Communication screen and change the sensor number to the value just entered in the parameter screen.
  4. Then click “Save Configuration”.
  5. Other parameters can be changed to suit your application as needed.

06:17 LEVEL APPLICATIONS
Please note that for Level applications, distance parameters such as empty/full/max must be entered in millimeters.

06:27 PRESSURE APPPLICATIONS
Pressure application parameters will be entered in PSI.

06:32 REGISTER 300 - RAW SENSOR OUTPUT
When reading the sensor output, register 300 will display the raw sensor output.

06:39 REGISTER 303 - CALCULATED OUTPUT
Register 303 will display the calculated output; this output has been calculated using the units and offsets you have selected in the parameters applied to the raw sensor output.

6:53 ANALOG OUTPUT FOR RS-485 DEVICES
Some RS-485 devices also have an analog output. You can change your analog output settings in APG modbus. 4 and 20 milliamp output setpoints can be entered in APG modbus in the 4 and 20 Set parameters.

You can also fine tune the output values using the 4 and 20 Cal parameters; analog outputs are set up at the factory and should not need to be changed.

It is important to note that the register addresses shown in APG modbus will be different if read through another RS-485 interface such as a PLC or custom program. This is because APG’s modbus addressing begins at address 1; Thus, all parameters would be found at an address 1 less than that shown in APG modbus. For instance, if reading the calculated sensor output you would read address 303 in APG modbus; for the same calculated sensor output using a PLC you would read address 302.

08:02 NEED SUPPORT?
If you have problems communicating with your sensor or with setting up your device parameters, please feel free to contact our Application Engineers at (877) 373-5940. You can also find more information and resources such as Live Chat.