Everything posted by Rayliegh
Rayliegh posted a topic in MitsubishiHello all, I'm using MC Protocol Format 4 to communicate with a VB6 application on a PC. I want to make some slight modifications, and I am getting a sum check error being returned by the module to my application. I believe (haha) I am calculating the sum check code correctly for Format 4 as most commands do work (reading for example). I was wondering if anyone knew of the buffer memory location on the QJ71C24N card that stores what the card is calculating for the sum check? This way I can have a troubleshooting tool to see what I am calculating wrong. I have looked through the manuals (application/basic) for the C24 already as well as the Melsec Reference Protocol manual. I have attached the error code for reference, again, I am only looking for what the C24 calculates as the sum check code. Thanks
Hey Gambit, thanks for responding. Yes! We have added our PCs to that list to a PLC during a test (sorry, we've done so much messing around that I forgot) and we have been able to connect that way. The thing is we have lots of people working on our PLCs (so different PCs touching them) AND our plant has a DHCP server, so our IP addresses that we use to connect have the potential to change once we lose that lease. Since we are running production, adding to this list is difficult since we have to reset the PLC. If there was a way to add IP addresses to this list through logic (buffer memory address in the ethernet card perhaps) that could work for us. Also, on other lines that use this setup, we are able to connect, without adding the PC to the list (using Automatic Response System in the setup). Let me know your thoughts. EDIT: Added screenshot of a PLC in another area that I am remotely connected to WITHOUT having my PC's IP address in the system exchange table. Evident because you can see me monitoring that module with the connection set to ethernet.
Hello all. Long time forum reader, first time forum poster. I'm in a controls role (first job out of college) and this has had me stumped for a while: We have our PLCs connected to our plant network through QJ71E71-100 cards. We use them for data collection/applications with OPC. For that purpose, it works fine. We also use the "Station No. <-> IP Information" settings with conjunction with JP.READ and JP.WRITE to send information between some PLCs through the plant network, it also works fine. For the PLCs that we do not use the "Station No. <-> IP Information", remote connecting works well, no problem. The problem we have is we want to connect to the PLCs remotely for troubleshooting/monitoring. Any PLC that use JP.READ / JP.WRITE commands and has the "Station No. <-> IP Information" setup (Table Exchange System), we can not connect to remotely. It gives the standard error message as if we are connecting to something that doesn't exist. This has been happening for years (same issue with GX Developer). We have tried new Ethernet cards with newer firmware. We have verified that we are not trying to use an occupied station number, we are using the correct network. Mitsubishi Reps have been stumped and point to our IS department as being the issue. We have talked to our IS department about this with our Mitsubishi Reps, our switches/hubs have the same configurations throughout the plant (by the way other lines don't have this trouble, even though they use similar commands) I've looked at buffer memory settings of other lines to see if there are any differences between ours, and theirs and there were none. I've attached screenshots of the error message that we get when trying to connect to one of these PLCs. Does anyone have any insight on this problem? If anyone needs more information, feel free to respond to the topic. Also greetings all, I've learned a lot for this forum in general.