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Nacho

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Posts posted by Nacho

  1. I have some problems with analog SSR (Celduc, Carlo-Gavazzi, etc brands) when I try to control from an 4-20mA analog output of OPLC.

    For example with the V200-18-E2B the load impedance is 500Ω maximum for current output. The input dynamic impedance of the SSR is ≥ 100 Ω but a drop in voltage ≤ 8 VDC @ 20 mA.

    The application doesn't work from 4-8mA, I suppose the dynamic impedance of the SSR will be higger than 500Ω.

    I found one solution to use several SSR with an analog output, inserting a Power Suply between the output and the SSR. Do you use it any time? does it secure for the analog output of Unitronics?

    Look at the image:

    powersuplyforssr.jpg

  2. I know it's possible with the Advanced Web Server to download a file from the SD to the PC via web explorer. Now I have a finished application where the customer needs to download the CSV without use the SD Card Explorer. Copy and paste all the application to the .vlp with the embedded webserver is a task for titans but I don't know how to start to make a simple application to download a CSV. It will be about chunks...

    Anyone can help me?

    Project: A PLC with IP 192.168.1.201 and a CSV called test.

    Download from internet explorer: http://192.168.1.201/EXCEL/TEST.CSV

  3. I have a V350 with trends and csv to SD. It works well but sometimes when the customer switch on the PLC we see the SB217=0. If you remove the SD and insert again the error is the same.

    I have seen that the only way to back to run is remove SD from OPLC, to insert in a PC doing nothing more and back to the OPLC.

    The application is a datalogger, if we have problems with the SD we will have a serious problem.

    Any idea to resolve it?

  4. We have several projects with Circutor, Carlo-Gavazzi and Entes simple powermeter with modbus serial port. The most of them because their datalogger are expensive. With OPLC the possibility of add digital and analogs inputs improve the application.

    I think if Unitronics will have a low-costg powermeter like an option we increase the sales about 100-200 units/year. It depends of the final price and the software we can develope. Circutor and Carlo-Gavazzi sell a lot of powermeters because their software of analysis.

  5. Apple world and android too. Everyday someone ask for monitoring their industrial machine from the smartphone. But there are two problems around this: 1.- how to connect to the PLC and 2.- what is about security?

    I think the solution will be web-service, it's a simple way to access to the machine. But it will be necessary learn to works with VPNs, DNS, HTTP.

    At this moment we are solving this kind of applcation with eWON, a modem-router "something-more" communicating with the OPLC Unitronics but it's a bit expensive for a lot o simple applications. I hope the next generation of OPLC Unitronics will able to add more control to GPRS, 3G connections, in cibersecurity and easy of use.

  6. I developed an application with ASCII in Jazz following the next explanation of Help:

    Communication Utilities

    Use this utility to enable your controller to receive data from external devices, such as bar-code readers, via an RS232 port. Since there is no Ladder element for this function; you perform it by storing values into SIs.

    Note that the communication settings stored into these SIs only take effect at power-up.

    SI

    Parameter

    Value to Store

    Notes

    141

    STX (Start of Text)

    Select one of the 3 STX option by storing its value into SI 141:

    · 0-255(ASCII)

    · -1: No Start of Text (not recommended)

    · -2: No Start of Text (Enables access by Unitronics PC applications)

    The STX parameter indicates where the data block begins.

    · -1: Note that the ASCII character '/' (backslash) cannot be used to indicate the start of the data block.

    · -2: enables applications such as U90 Ladder and Remote Access to access a networked PLC. Note that these applications use the 'backslash' character ( / ) (ASCII character 47) as the Start of Text (STX) character.

    142

    ETX (End of Text)

    Select one of the 3 ETX option by storing its value into SI 142:

    · 0-255(ASCII)

    · -1: ETX marked by Length

    · -2: ETX marked by 'Silence'

    The ETX parameter indicates where the data block ends. When the ETX is registered by the function, SB 60 turns ON.

    · If you use an ASCII character (0-255), note that if this character occurs after the Length parameter defined in SI 143, SB 60 turns ON.

    · Selecting -1 causes the function to use the length of a data block alone to determine its end.

    · Selecting -2 causes the function to use the duration of silent time following the STX to determine the end of a data block.

    143

    ETX Length or Silent

    · Length: up to 128

    (relevant if you store -1, Length, into SI 142 to provide ETX)

    · Silent: up to 24000

    · This defines both the length of text, or silence, that signals the end of text.

    · Note that the duration of a silent 'counter' unit is approximately 2.509 mS. The 'silent' value should be lower than the TimeOut value.

    · When defined as length, SI 143 cannot exceed SI 144.

    144

    Maximum Length

    Up to 128

    · This is the maximum legal length for received text.

    · When the maximum length is exceeded, the Receive Buffer is automatically cleared, and SB 60 is turned OFF, enabling new data to be received.

    · This can be used to detect buffer overflow.

    145

    Start Address: Receive Buffer

    MI Address

    This MI contains the start address for the vector of registers that serves as the Receive Buffer.

    60

    Number of Bytes currently in Receive Buffer

    Read only

    SI 60 indicates how many bytes of data are currently in the Receive Buffer.

    61

    Number of Bytes in Receive Buffer when SB 60=1

    Read only

    SI 61 indicates how many bytes of data are in the Receive Buffer when SB 60 turns ON.

    146

    Copy Data: Format

    · 0: copy each received byte

    · 1: copy in groups of 4 received bytes.

    · 0 causes each separate byte to be copied to a separate register including STX and ETX.

    For example, if the PLC receives an STX character, 4 data bytes, and an ETX character, the data will be copied into a vector of 6 MIs: the first containing the STX, 4 MIs for the data bytes; the last MI will contain the ETX.

    · 1 causes every 4 bytes to be copied to a single register, without the STX and ETX. This is used when the received data is in numeric format.

    For example 12345 would be copied to 2 consecutive MIs. The first MI would contain 1234, the second would contain 5.

    140

    Start receiving

    300

    In your application, use this to call the function after you have entered all of the other parameters.

    Note that when you run Test (Debug) Mode, the current value in SI 140 will not be displayed.

    SB

    Description

    Notes

    60

    Data Successfully Received

    Read only. Turns ON when the ETX condition is registered by the system.

    61

    Copy Data in Receive Buffer to MI Vector

    Write only.

    · Turning this SB ON causes the buffer contents to be copied to the MI vector defined in SI 145. The data will be copied according to the format defined in SI 146.

    · If SI 146 is set to 0, this SB can be set at any time.

    If SI 146 is set to 1, this SB can be set after SB 60 turns ON.

    62

    Clear Receive Buffer,

    Clear SI 60,

    Clear SI 61,

    Reset SB 60

    · This SB must be turned ON to enable a new message, or data block, to be received.

    · Turn this SB ON to enable data to be received before the maximum length, defined in SI 144, is exceeded.

    Note that if no data is received for a period exceeding the TimeOut, you will lose the data in the buffer.

    To see how to use the Communications Utility, check the sample application Read Card - Display Number Value.U90. This may be found by accessing Sample U90 Projects from the Help menu.

    This application demonstrates how to read a magnetic card number using an "IDTECH" card reader, then display that number on the PLC's screen. The card reader transmits the number in ASCII characters in this format:

    < %?[CR];xxxxx?[CR] > where xxxxx is the card number.

    The ASCII character used to mark the Start Of Text (STX) is < ; > (semicolon). End Of Text (ETX) is marked with the character < ? > .

    Since the card number is 5 digits long, the card number is copied to 2 separate MIs. The MIs are linked to 2 variables that are shown on the PLC's screen in 2 separate Displays.

    The parameters must be written into their respective operands using one scan condition. For this purpose, it is recommended to use SB 2 Power-up bit, as shown in the sample application.

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