Extending IO (analog/digital)



  • There are digital inputs available but only for the 1Wire network but they are too slow for your application. So sorry for that…



  • What do you mean with too slow?
    What is needed for 1wire connection of 2 unipi's? One unipi with RPI and the other without RPI. Between both an RJ45 wire. On RPI I use Rexcontrols. Are there some examples for that or has anyone an solution for that?



  • @RoethelC:3a8ktl6n:

    What is needed for 1wire connection of 2 unipi's?

    Connecting 2 UniPis via 1-Wire is also not possible, UniPi is always a 1-Wire master and there can be only one master in the 1-Wire network.

    @RoethelC:3a8ktl6n:

    One unipi with RPI and the other without RPI. Between both an RJ45 wire.

    Using UniPi without RPi is not possible. You need some "brain" to process the digital inputs.

    @RoethelC:3a8ktl6n:

    On RPI I use Rexcontrols. Are there some examples for that or has anyone an solution for that?

    You can use 3 UniPis with 3 RPis and connect them via Ethernet. Data exchange can be based e.g. on UDP:
    https://github.com/rexcontrols/REXexamples/tree/master/Integrating_external_devices/UDP/Generic_Sender_Receiver



  • Hello! Adam Skorpik recommend me to the forum and said Jaroslav may be able to help me…
    I am using the Unipi for industrial control and need a minimum of 8 analogue inputs.
    Adam said this input board is still under development.
    I am thinking either a 0-10v to pwm converter board (Hong kong special ) for each input needed or a siemens logo doing that job completely with rex comms to the unipi/pi combination. What do you think and what would you recommend? Many thanks, Adam.



  • @adz996:2b6xm6me:

    I am using the Unipi for industrial control and need a minimum of 8 analogue inputs.

    • If you are OK with 0-10V inputs, I'd go for Siemens LOGO 0BA8 with 2x AI extension (1MA00-0BA2). LOGO is a wonderful I/O unit for the Raspberry Pi with the REX Control System

    • Another option might be Click PLC with AI extensions which you can get from e.g. Automation Direct. You program it to act as Modbus TCP master or slave.

    • Or any Modbus TCP I/O gateway like Wago 750-352 or Turck BL20-E-GW-EN with corresponding analog input module(s). It acts as Modbus TCP slave.

    • In all cases you will need Modbus or S7 communication driver for the REX Control System.



  • Hi Jaroslav, I hope all is well!
    I need to use a rotary encoder through one of the digital inputs. Is the Unipi PNP or NPN collector type input?
    I know development takes time, as I am doing the same but a detailed (Mitsubishi level of information) specification sheet saves time and adds desire and credibility. Total respect all the same…
    Thanks again,
    Adam.



  • @adz996:nycd5am3:

    I need to use a rotary encoder through one of the digital inputs.

    How many pulses per second does the encoder generate at maximum speed? In general, I do not recommend using Raspberry Pi GPIO for reading encoder pulses. Use microcontroller or specialized hardware for this purpose. IMHO a rotary encoder typically uses 2 signals…

    @adz996:nycd5am3:

    Is the Unipi PNP or NPN collector type input?

    PNP, you have to supply voltage to the input.

    @adz996:nycd5am3:

    I know development takes time, as I am doing the same but a detailed (Mitsubishi level of information) specification sheet saves time and adds desire and credibility.

    Your comment should be targeted somewhere else. Please note that I am neither a developer nor employee of UniPi.



  • Hi Jaroslav,
    Thank you for your reply!
    I will use an Omron encoder and max revs will equate to 216khz at 12-24v.
    What do you think, possible to be read by the pi through the unipi digital input?
    Appologies for other comments. I think the unipi is such a great product and I only want positivity.

    Adam.



  • @adz996:28fty4kx:

    I will use an Omron encoder and max revs will equate to 216khz at 12-24v.
    What do you think, possible to be read by the pi through the unipi digital input?

    I do not believe this is possible. Note that the inputs are evaluated by the Raspberry Pi CPU so processing the encoder pulses will compete with all other tasks in the operating system, resulting in loosing pulses. Plus the optocouplers on the inputs are not able to pass through such high frequencies. My recommendation is still the same: Use microcontroller or specialized I/O hardware for this purpose.



  • use encoder 32:5 . you can give 32 input and you will get only 5 bit as a result. i.e.only 5 pins of controller.