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Found 4 results

  1. Continuous sine wave problem

    Hi,  I encountered specific problem during work with PLC&HMI application. The main task of that system is controlling torque changes of induction motor with inverter&analog PLC output. There are few built-in functions to change torque: exponential, constant, trapeze and unlucky sine. All functions are implemented as array of 1500 values. When array reaches 1499 element, it comes back on first position and so on. It works without any problem for exp, constant, trapeze and sine wave with natural numbers of frequency e.g. 1Hz, 3Hz etc. The trouble appears when we want to control torque with float value of frequency and unfortunately its the most important part of that project. When the float value frequency is chosen, the last element of array is totally different than the first one. In result, in every period of array, appears drop of value. Check the attachments to comprehend what's going on. The first image shows GXWorks restriction of index. The second image shows how does it look on simulate screen, where it's representation of PLC registers D2000 - D3499. On third and fourth images you see values of registers in Device Memory Batch of GXWorks. Fifth image shows the script which I work on. Do you have any ideas how to implement float values of frequency in correct way? I should make an opportunity to online change of sine frequency in continuous way between 0 and 10 Hz, with 0.2Hz step. I will be very grateful for any advice.  Greetings, J
  2. CJ1M-CPU23 Reading a square wave

    Hello, I have a flowmeter (macnaught flowmeter) which says that it outputs a 2 square waves. I am unsure how to connect the flowmeter to my plc (CJ1M-CPU23), do I need an additional unit or can I use the general purpose IO things mentions in the manual (IN6-9 say they are high speed counters)? Any advice would be appreciated. Thanks, Jay
  3. Square D 8881

    Can anyone give me so information about a  Square D 8881  especially the programing of timers using ml1 math/logic interface. 
  4. I have a Square D program for a very old 600 series processor which was written using SFW-374 software. Can any body help me out with the software to create a printout or just provide a printout of the PLC logic in word format or xps type document file? If any body can I will attach program to listing. Thanks in advance