Posted 3 Nov 2023 Hi all , I have been using MELSEC - Q series plc for the past two project i dont find any issue with that but for the third project used same PLC same model but there is issue which I found unable to resolve The issue is when i try to communicate PLC using LAN cable by direct ethernet connection it works normally but by communicating using HUB network I cannot communicate, I checked all the parameters setting, I dont know what is the issue even contacted mitshubshi service to troubleshoot but they are not responding So here i am for your guidence to solve this issue see the images below to analyse this issue This connection is direct ethernet connection which works normally The parameters are set and writed to PLC The IP is set to my PC for communication When i try to find the cpu in the network it shows the cpu IP After that I checked for connection Test it show error I have also attached the Network route which i used to communicate Network Drawing.pdf I hope someone will help me to solve this issue Thank you , madhan ravichandran Share this post Link to post Share on other sites
Posted 3 Nov 2023 You don't have the subnet mask configured in the PLC. Share this post Link to post Share on other sites
Posted 4 Nov 2023 HI @pturmel Yes i have tried using subnet mask and tried to ping the IP but there is no response from PLC Share this post Link to post Share on other sites
Posted 5 Nov 2023 Try to add gateway or router address in your PLC setting. Share this post Link to post Share on other sites
Posted 5 Nov 2023 On 11/4/2023 at 9:35 PM, madhan said: tried using subnet mask Your screenshots show a subnet mask for the PC, but empty in the PLC. Both devices need a subnet mask. Share this post Link to post Share on other sites
Posted 6 Nov 2023 6 hours ago, Nugro said: Try to add gateway or router address in your PLC setting. 2 hours ago, pturmel said: Your screenshots show a subnet mask for the PC, but empty in the PLC. Both devices need a subnet mask. Hi I have added gateway and subnet mask to the plc and tried to ping IP there is no response see below images for your refrence i dont get the issue why this happens Thanks Share this post Link to post Share on other sites
Posted 6 Nov 2023 (edited) are you connected to wifi ? It might be trying to ping over your active internet connected device instead of the ethernet port. And check your Ethernet cables to/from that hub. A bad cable is a great way to beat your head against a wall for a few hours. Edited 6 Nov 2023 by WattUp 1 person likes this Share this post Link to post Share on other sites
Posted 7 Nov 2023 hi @WattUp No I havent connected to Wifi I check the both way ping when PLC ethernet directly connected to my PC and when its connected to the HUB there is no response I even clarified is the cable has fault I swtiched the cabel to new one but there is no response it only works on direct communication method Share this post Link to post Share on other sites
Posted 7 Nov 2023 Are you using hub/switch/managed switch? Are you able to communicate with any other devices connected to the hub? Which devices support auto mdi-x? (auto crossover) Are your cables straight through or crossover? Share this post Link to post Share on other sites
Posted 7 Nov 2023 HI @chelton I use d link hub switch , yes there are devices which I mentioned the other two plc, which are same model are connected to the same hub which can be communicated normally. my cables are staright through . Share this post Link to post Share on other sites
Posted 8 Nov 2023 If you are connecting directly to Q port, than you need crossover, if you are connecting through switch than straigth cable is ok. It could be that with hub you need crossover cable. Share this post Link to post Share on other sites
Posted 8 Nov 2023 HI @Goran Vuckovic I Want it to connect through HUb as it is used for both for socket And HMI communication but if cable is fault why it happens to connect through direct Q port ? Share this post Link to post Share on other sites
Posted 8 Nov 2023 I didn't understand your previous question, but I will try to explain. Q port doesn't support Auto MDI-X so you will need crossover cable to connect PC to PLC. Switches support Auto MDI-X, so you can use either straigth or crossover cable. HUBs most likely do not support Auto MDI-X, so you will likely need to have crossover cable from HUB to PLC. Remember that idea is to connect PLC Transmit to PC Receive and PC Transmit to PLC Receive. Share this post Link to post Share on other sites
Posted 8 Nov 2023 On 11/7/2023 at 3:09 AM, madhan said: HI @chelton I use d link hub switch , yes there are devices which I mentioned the other two plc, which are same model are connected to the same hub which can be communicated normally. my cables are staright through . try to take a ethernet cable from a known good PLC connection and connect it to the troublesome one. Could be a bad port in the switch. I dont see anything in the configuration that looks wrong. Im pretty sure the crossover thing is taken care by the ethernet port on the PC.. unless your PC is pretty old Share this post Link to post Share on other sites
Posted 9 Nov 2023 hi @WattUp I changed the ethernet cable from my working PLC and connected to it (my laptop support crossover) ,then I tried to Ping there is no response is there any firmware or any factory reset for this series , I also tried Formating the total memory of PLC and uploded the parameters to recheck the issue still no response The plc happens to communicated only in direct ethernet port Share this post Link to post Share on other sites
Posted 9 Nov 2023 Sounds like direct connection uses a layer 2 connection, and connection via hub uses layer 3. Although you can connect when connected directly what do you receive when you ping the IP address of the PLC? What does the output of ipconfig /all produce when connected via the "hub/switch". Share this post Link to post Share on other sites
Posted 9 Nov 2023 Hubs are Layer 1, switches are Layer 2 and there are Layer 3 switches/routers. I have connected many Q PLCs in my life, and if you connect them directly you need crossover except if your PC has Auto MDI-X, and it will have if it is Gigabit port. If you have problems connecting it with hub, just buy simple switch instead of hub and try it. Today switches are so cheap that it costs you or your company more to write all this posts than to try it. For example Tenda SG105, unmanaged , 5-port, Gigabit switch costs 10$. Share this post Link to post Share on other sites
Posted 9 Nov 2023 Let me show I tried with HUB for both of my perivous PLC's its working normally check these images . when I find my CPU it shows all my PLC The each connection Test are done by COnnection Via Hub mitshubshi service responded for this they came online and checked for the issue but even they cannot solve it , they insist onsite visit but they cost more, We are unable to claim warrenty as we bought all three PLC in 2020 each project took a year, so I came here if someone can solve it for me I checked with all the HUB / switch device we have but unable to communicate I will wait for another week if anybody has any solution let me know ,otherwise i will go for the service Thank you Share this post Link to post Share on other sites
Posted 9 Nov 2023 1 hour ago, chelton said: Sounds like direct connection uses a layer 2 connection, and connection via hub uses layer 3. Although you can connect when connected directly what do you receive when you ping the IP address of the PLC? What does the output of ipconfig /all produce when connected via the "hub/switch". HI @chelton Check these photos of Ethernet Diagnostic when I connect through Direct ethernet port of Q PLC Thank you Share this post Link to post Share on other sites
Posted 9 Nov 2023 Hi @madhan looking at the screenshots the MAC address of the unit is FFFF.FFFF.FFFF . This is a broadcast address. The MAC address would not be user adjustable so you may have a defective unit. 2 people like this Share this post Link to post Share on other sites
Posted 9 Nov 2023 (edited) Chelton might be on to something . that should not be FFFFFFFFFFFFF just another thought.. when you wrote those ethernet settings, did you do a hard reset? [ Hold run swtich to left until rebooted ] Edited 9 Nov 2023 by WattUp Share this post Link to post Share on other sites
Posted 10 Nov 2023 12 hours ago, WattUp said: Chelton might be on to something . that should not be FFFFFFFFFFFFF just another thought.. when you wrote those ethernet settings, did you do a hard reset? [ Hold run swtich to left until rebooted ] yes I have done hard reset and powered down plc and turned it on Share this post Link to post Share on other sites
Posted 15 Nov 2023 Any luck? Do you have a spare CPU that you can load up the program and trial? Share this post Link to post Share on other sites
Posted 16 Nov 2023 No it is not working I have seen a post that says if we remove the CPU battery and power it down for a day then it will go it is factory state even tried this method but no Luck just asking is there any firmware update or procedure do a full factory reset for this CPU I dont have spare CPU better go for service I think Share this post Link to post Share on other sites
Posted 16 Nov 2023 46 minutes ago, madhan said: No it is not working I have seen a post that says if we remove the CPU battery and power it down for a day then it will go it is factory state even tried this method but no Luck just asking is there any firmware update or procedure do a full factory reset for this CPU I dont have spare CPU better go for service I think I'm no Mitsubishi expert by any means, but after so much time i think you should replace CPU and not worry about getting service. I think you have exhausted all avenues to get your existing unit working. Share this post Link to post Share on other sites
