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About engMoH

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  • Country Egypt
  1. i am using a VSD Altivar71 and controlling it through serial MODBUS communication, the probllem is sometimes after stoping the motor the drives gives the "nst" fault which means according to the programming catalouge "freewheel stop" it doesn't do that all the time but it happens a lot and after uploading the code again to plc the problem is gone for a while before it happens again. i am sure that the fault is happening because if communication because when i controll the drive from hmi it never gives that fault, i checked the setting and tried different cables but it still gives "nst" and motor never moves, i found that in catalouge but i am not sure how to address the problem.
  2. hey @Quant  i found this useful link https://www.schneider-electric.com/en/faqs/FA213155/  but as i thought all examples was mentioned is that plc writing on HMI, the questions is : if HMI slave and plc is master can i use buttons in HMI to switch on devices connected to plc ? and not jusr reading values from plc ? i will go with try and error anyway but i wanted to know if this was possible before
  3. i have a plc Modicon M340 , HMI hmigxu3512x and VSD Altivar 71, and i only allowed to use serial MODBUS port in plc, now the VSD is a slave and is controlled with plc as a master how can i add the HMI to this configuration?? i know that this model of HMI can be slave but then how it will give orders to PLC to start stop etc.. and if PLC is slave how it will control the VSD??
  4. when i try to upload a code to m340 it give me this message  "This isn't a valid PLC Address, or PLC is busy , or media is off." whatever i use usb or tcp/ip port, it don't always give me the message but most of the time it does and i have to unplug and replug the cable many time until it upload the code, i am sure it's not a cable problem what can it be?
  5. hi Ramadan i am not expert but i have the same drive and i got it work through MODBUS serial RS485 and it is very easy you can try if your plc has serial port but i never use fipo bus  speed shouldn't be random it may be a defect in the gearbox of your motor you can use encoder and make a feedback loop to the driver  
  6. Hi Quant thank you again, it worked now i can operate the drive through ladder diagram. still one small problem to end it i hope to solve it. every time i download a code on plc the drive give modbus fault and won't operate until i disconnect power to VSD then reconnect it again. i want to reset fault when i press start. i found this in catalogue, and what i get is that i should write 177 in the address 7124 every time in the starting is that right? didn't try it yet, if you have any thoughts please share it with me.
  7. Hi Quant, thanks it worked when i write 6 then 7 but in the address 8501 not 0 . now i want to make a ladder program to make it Automatic i tried to make ladder program to write 6 then 7 in same register but it keep writing 6 then 7 forever so the motor just make sound but is not moving. can you help me on that ? it has to write 6 then 7 for one time and not keep writing them forever, thanks in advance.
  8. I connected between Altivar 71 VSD drive and Modicon M340 PLC through MODBUS RTU RS485 and the communication is ok, now i want write  a command word using Write_var function to control the VSD but I find very confusing. first : it's written in cataloug that bits from 0 to 15 can be assigned to commands , is that done from HMI? i  can't find anywhere on HMI. second : in the function (both read and write) obj element can be int or bool bit but the EMIS element  in 'write_var' function (data going to VSD registers) only accepted if it's array of int not bool so i can't trigger the bits i want !! third : like the picture the VSD showing it's in NST mode and it says that it won't start until hex value of 6 written to command word but the catalogue says that only bit 0 is assigned(to forword command) and other 15 bits are free for user to assign and 6 in hex (0110) bit 1 and bit 2 still not assigned to any thing  !! i hope anyone could help 
  9. i already did that quant, i got all thess files from schneider site and other websites and read them all, still most of them explaining programming the drive through the display that i don't have i need to do it from software "somove" but the help of the program is so cursory and no useful tutorial on youtube so i asked here, my problem is that i don't know how to control the drive by plc through unitypro and somove without using the driver display i am new to the field so i may missing some concepts, thanks in advance.
  10. i have altivar 71 speed drive without graphic display, and plc modicon m340 with only ddi and ddo modules and no communication module, i want to control the altivar 71 from plc through serial modbus but i don't know how to do so is there any book i can read or place to get information from ? all catalogues only explaining the  graphic display which i don't have, i only need to conrol the speed and start stop function no other parameters!!