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Gabriel Franco

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Posts posted by Gabriel Franco

  1. If the manufacturer offers EthernetIP, then you don´t need those ladder functions, just a few steps to configure the PLC as Ethernet/IP scanner importing the EDS of the device.  It will create the structures and IO tags required to comunicate to/from the valve controller.

    Take a look to the examples that can be downloaded from https://downloads.unitronicsplc.com/Sites/plc/Unilogic/UniLogic_Examples.zip

     

     

     

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  2. It is not very difficult to connect to the PLC and download the program to it (from Unitronics' perspective, download is from the PC to the PLC). You must have a USB mini B cable or serial cable and a USB-RS232 converter. But downloading the program doen´t load values to the parameters, as Flex mentioned. Parameters are saved in a separate file (txt or bop file) only if someone did it intentionally.

  3. According to the Alicat manual, "The device setpoint should be sent as a 32-bit IEEE floating point value. Setpoint values must be sent together in a Write Multiple Registers command. Any writes to only one half of the setpoint value will cause an error. Setpoint is ignored on devices without a controller".

     

    Are you fulfilling this requirement?

     

  4. Based on my experience, the Vision Autotune FB used on slow response systems like temperature control, doesn´t give optimal PID parameters except by sample time. That´s why I´ve tuned those systems manually.

    5 hours ago, Hyugin said:

    You said about the P being a 1 is what makes the I and D stop affecting the controller, but if change P to 50, 100 or 1000 and then change the others, it is the same. Only P seems to take effect in the output. 

     

    Probably you don´t need D, so set it to 0.

     

    5 hours ago, Hyugin said:

    I just doesn't understand what turned out so wrong in these parameters that somehow it turns off the heaters almost completely (6.46mA output) after it reaches 500.0, then it drops to 549 and is never able to reach the SP again.

     

    It may be caused by integral wind-up. You can check it looking at PID status register. In that case, what I do is to reset it manually

  5. The PLC does not send information, it is the SCADA that gathers and/or put data from/to PLC using Modbus TCP protocol.

    I´m not sure if USR-W630 is the most convenient device here because it´s a gateway (Modbus RTU/Modbus TCP) and basically what you need is an Ethernet to WiFi converter or  an Ethernet switch with WiFi capabilities (unless you can wire).

    Be aware of WiFi networks can be unstable and based on data rate collection, you may loose important data; that being said, it's better to have a wired connection between SCADA and PLC.

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