Hello everyone, I am seeking assistance with clearing input data from a Scanner. I attempted to use COP and MOV instructions to reset the buffer to Zero, but the input type data continues to flood in from the scanner even after I disable the MOV instruction. Unfortunately, I am unable to utilize serial port instructions due to restrictions on this controller. Can anyone offer a solution to efficiently clear the input data from the Scanner?
Could you please furnish additional details? Which programmable logic controller (PLC) model are you currently utilizing? What brand and model is your scanner, and what is the connection method to the PLC?
The PLC model I am utilizing is the 1769-L36ERMS2, with a 1734-232ASC Module communicating through RS-232 connected to a 1734-AENTR backplane. The scanner being used is the DataLogic GBT4500. An issue I am encountering is receiving cumulative data from multiple scans, as I am unable to clear the buffer between scans due to the lack of support for ACL (clear Buffer) instructions in this PLC model. How can I clear the previous scan data to prepare for the next scan?
Shivsrikakolum shared details about the equipment being used for scanning purposes. The PLC being utilized is a 1769-L36ERMS, with a 1734-232ASC Module connected to a 1734-AENTR backplane for communication through RS-232. The scanner in use is a DataLogic GBT4500, providing data in hex format that needs to be converted to a string. The issue at hand is that the scanner retains previous scan data, leading to a mix of old and new readings. Unfortunately, the PLC being used does not support the ACL instruction for clearing buffers. If you are facing a similar problem, consider alternative methods to clear previous scan data for a clean slate before initiating a new scan.
Referencing the 1734-232ASC user manual, have you properly configured the buffer length? It is essential to thoroughly review the manual to ensure that the module is set up correctly to process the data received from the scanner efficiently.
It seems like there may be an issue with the scanner causing it to resend the previous data along with the current data. Is there a delimiter, such as a
Hey there, it sounds like you are dealing with a pesky issue! Just to pitch in, have you tried using Scanner's nextLine() method after your input statements? This often helps gobble up the rest of the line, including newline characters that could still be lingering in your scanner buffer. Do remember that this method returns a String that you'll need to discard if you're not using it. This is just a common approach in Java but it would help to know which language you're working in.
Hey there! It sounds like you're having quite an issue. While I understand that your controller doesn't allow use of serial port instructions, have you thought about using a different method to clear your scanner input? Instead of using the COP or MOV instructions, you might consider creating a loop that reads in the remaining input data until no data is left. Essentially, what this does is "consume" all the remaining data, effectively clearing it out. Give it a try and let us know how it works out for you.
Hey there, it sounds like you're dealing with a bit of a tricky situation. One potential solution could be to use a combination of a while-loop and the Scanner's hasNext function. Essentially, you can create a while loop and use the hasNext function in the conditional statement. As long as the Scanner has input, it will continue to consume it. When there's no more input, the loop will stop and the buffer should be clear. Essentially something like: while (yourScanner.hasNext()) { yourScanner.next(); }. Hope this helps you out!
Hello there! You could try flushing the scanner using the while loop, with a condition that checks if there's a next line in the input using scanner.hasNextLine(). This will keep iterating until there's no more input. Bear in mind this method only works for buffered inputs. If this method isn't applicable in your case, you might need to consider other alternative workarounds, given the restrictions on your controller.
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Answer: 1. How can I clear input data from a Scanner in a 1769-L36ERMS PLC? - One approach is to use COP and MOV instructions to reset the buffer to Zero. However, if the input data continues to flood in even after disabling the MOV instruction, consider alternative methods since serial port instructions are restricted on this controller.
Answer: - If the traditional method of using COP and MOV instructions is not effective in stopping the input data flow, explore other techniques that do not rely on serial port instructions due to controller restrictions.
Answer: - Yes, consider seeking alternative solutions or methods that do not involve serial port instructions to efficiently clear the input data from the Scanner on the restricted controller. Experiment with different instructions or approaches to manage the input data flow effectively.
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