DavidG (Customer) asked a question.

Edited August 20, 2024 at 12:54 PM
Issue connecting RS-485 pressure sensor to P1-540

I am trying to connect a CS Instruments DPS-16 pressure sensor to a productivity 1000 PLC and can't get it to work. I was following the closest guide/example program I could find but no dice. I am a novice at this assume its something basic.

 

Data plate on Sensor:

Image (3) 

Hardware config:

Untitled2 

Modbus Read command:

UntitledAny Ideas? I feel like its probably an address issue but I don't know enough about what I'm looking at to know for sure.

Click to open rich previewProductivity 1000 Series PLC Modbus RTU Serial CommunicationPlay

Productivity 1000 Series PLC Modbus RTU Serial Communication

Productivity 1000 Series PLC Modbus RTU Serial Communication
The productivity series of PLCs comes with 4 built-in communication ports for easy connectivity to your PC or various industrial networks. Serial protocols like Modbus RTU can be utilized with either the RS232 or RS485 ports on this PLC. Modbus RTU is an open (published) protocol that uses the Master / Slave architecture. It's a widely used protocol in industrial automation controls.
We will be using the RS485 (2-wire) port to communicate with a Solo Process Temperature Controller. Modbus RTU will be the protocol used for this serial communication. The PLC will be the master, and the Solo process temperature controller will be the slave. You will soon see that the Productivity Series of PLCs is the best way to communicate with other devices. Let's get started.

More information can be obtained on our Website. This includes all of the links mentioned in this video.
https://accautomation.ca/productivity-1000-series-plc-modbus-rtu-serial-communication

Here are some previous posts in this Productivity 1000 PLC Series. A full list can be obtained at the following location:
https://accautomation.ca/series/productivity-1000-plc/
System Hardware
Installing the Software
Establishing Communication
First Program
https://accautomation.ca/productivity-1000-series-plc-first-program
Video
https://youtu.be/txr_wfd7y2w
Documenting the Program
https://accautomation.ca/productivity-1000-series-plc-documenting-the-program
Video
https://youtu.be/WhYTCMRSzk8
Monitoring and Testing the Program
https://accautomation.ca/productivity-1000-series-plc-monitoring-and-testing-the-program
Video
https://youtu.be/o9gdrrEMexw
Online Editing and Debug Mode
https://accautomation.ca/productivity-1000-series-plc-online-editing-and-debug-mode
Video
https://youtu.be/D-sDKMnw1gQ
Numbering Systems and Tag Database
https://accautomation.ca/productivity-1000-series-plc-numbering-systems-and-tag-database
Video
https://youtu.be/s-TAWomBeIs
Contact and Coil Instructions
https://accautomation.ca/productivity-1000-series-plc-contact-and-coil-instructions
Video
https://youtu.be/xMP9EEVlm1k
Timer Instructions
https://accautomation.ca/productivity-1000-series-plc-timer-instructions
Video
https://youtu.be/egUnU8paLCA
Counter Instructions
https://accautomation.ca/productivity-1000-series-plc-counter-instructions
Video
https://youtu.be/tEWAXWugxqI
Math Instructions
https://accautomation.ca/productivity-1000-series-plc-math-instructions
Video
https://youtu.be/xPJGC9LaYFc
Data Handling Instructions Part 1
https://accautomation.ca/productivity-1000-series-plc-data-handling-instructions-part-1
Video
https://youtu.be/ARK8F2q-kJU
Data Handling Instructions Part 2
https://accautomation.ca/productivity-1000-series-plc-data-handling-instructions-part-2
Video
https://youtu.be/3fvvfhy16SA
Array Functions Part 1
https://accautomation.ca/productivity-1000-series-plc-array-functions-part-1
Video
https://youtu.be/8ITrEWeBgPc
Array Functions Part 2
https://accautomation.ca/productivity-1000-series-plc-array-functions-part-2
Video
https://youtu.be/jO0z6-MpGqE
Array Functions Part 3
https://accautomation.ca/productivity-1000-series-plc-array-functions-part-3
Video
https://youtu.be/8M3LV-XihNo
Program Control
https://accautomation.ca/productivity-1000-series-plc-program-control
Video
https://youtu.be/QPrIzxDq16A
Drum Sequencer Instructions
https://accautomation.ca/productivity-1000-series-plc-drum-sequencer-instructions
Video
https://youtu.be/QZE8c4rw9QE
Data Logger
https://accautomation.ca/productivity-1000-series-plc-data-logger
Video
https://youtu.be/mM1zbbX7zVg
Web Server
https://accautomation.ca/productivity-1000-series-plc-web-server
Video
https://youtu.be/ZuZd3lqp87c

There are several reasons why we are using the Productivity 1000 Series Controller. Here are just a few.
- 50MB user memory - Can handle very complex applications easily.
- 4 built-in communication ports – Easy connectivity to your network.
- Data logging up to 32 GB on a microSD card
- Add up to 8 IP modules to communicate to your field sensors. This will give you a total of 128 discrete IO points or 32 analog IO channels.
- Free Software and 30 days of free training with every CPU from Automation Direct.
- Interactive PLC Configuration Tool
- Tag Names
- Auto discovery IO – Physical I/O tags will be generated based on each module’s position in the base.
- I/O Modules have QR codes under the wiring cover. This can be scanned so you can have the latest specifications / wiring diagrams for the module.
- Limitless PID – Auto tuning – Individual or Cascade Mode - etc
- Web Server and Mobile Access
- Advanced Software instruction set

The Productivity 1000 series of programmable logic controllers currently has all of these features built into the P1-540 CPU.
This CPU (Central Processing Unit) are also known as MPU (Multi Processing Units) because of the communication capabilities.

https://www.accautomation.ca

https://www.youtube.com/watch?v=6LqbOyrWQ88

  • 16 answers
  • 492 views

  • DavidG (Customer)

    Messed with more combinations of settings mentioned in this thread and eventually landed on this which appears to work. Thanks everyone for their help!

     

    image

    Selected as Best

  • ADC Community_02 (Automationdirect.com)

    1.) Can you provide a hand drawing or pictures of how you have the sensor wired to the plc RS-485 port?

    2.) What is the status of the LED indicator lights on the RS-485 port?

    3.) Provide a screenshot of dataview that includes your status tags from MRX instruction.

    4.) Provide screenshots of your devices configuration screens?

    5.) What data type is your serial pressure reading tag in the CPU?

    Expand Post

    • DavidG (Customer)

       

      1.) Can you provide a hand drawing or pictures of how you have the sensor wired to the plc RS-485 port?

      Untitled32.) What is the status of the LED indicator lights on the RS-485 port?

      only TX is blinking

       

      3.) Provide a screenshot of dataview that includes your status tags from MRX instruction.

      Untitled44.) Provide screenshots of your devices configuration screens?

      Untitled5The serial tab is in the OP, are there any other screens that are relevant?

       

      5.) What data type is your serial pressure reading tag in the CPU?

      Float 32 bit

      Expand Post

      • DavidG (Customer)

        I had not noticed that either status light was blinking since they're mostly obscured by the terminal block but since I'm trying to read and not write, I flipped the A and B wires and now its reading "serial pressure reading" as 3.22299e-44 which is much better than radio silence.

         

        Update: Since the e-44 value looked like a data type error that i have seen before, I changed it to an integer and it translates to 23. Neither value changes when swinging from ambient pressure to ~90 psi however.

         

        also now the "complete" and "success" tags flicker in sync with the "in progress" tag flipping off

        Expand Post

      • DavidG (Customer)

        well it's still not reading the pressure so I'm not sure what my next move is

      • ADC Community_02 (Automationdirect.com)

        Take some screenshots of your pressure device configuration screens to show how that end is set up.

      • DavidG (Customer)

        I'm not sure what that is or where I would access it

      • ADC Community_02 (Automationdirect.com)

        Got thrown off with the DS400/500 reference. Looked on their website and this is another type of device that can read those sensors.

         

        Their manual does not provide a lot of detail. I would call up their support and ask how to read the pressure out of that device. Mainly tag data type and starting Modbus address since those are not defined from what I can tell in the documentation.

        Expand Post

  • ADC Community_02 (Automationdirect.com)

    Instead of address 1 in your MRX instruction try address 35 or 36 depending on is 0 or 1 based to see if you get a reading.

  • DavidG (Customer)

    I tried 35 and 36 but no luck yet. I talked to their tech support yesterday and got the following:

     

    "I just spoke with one of our techs. I will attach below what he recommends trying to fix your problem.

    Please check the following:

     

    1. Modbus ID
      1. The Modbus ID of the DPS16 is printed on the type plate at the sensor. You’ll have to check the ID on the sensor itself.
    2. Modbus Address
      1. For reading the pressure the client needs to read register 36 with data type float and byte order C-D-A-B. See picture below."

    image Which was not super helpful since it directs me back to the DS400 as the master when I am trying to connect it to the P1-540

     

    Expand Post
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