Posted 20 Apr 2016 Hello, I have a logic diagram for a machine and i need to convert it to ladder diagram to program a STEP5 PLC. But there are few symbols that i don't know what they are. I've circled the unknown elements and i have written the signals that goes to those blocks. I have also added a schematic. Sorry for the pictures quality. Thank you. Share this post Link to post Share on other sites
Posted 21 Apr 2016 Hi A_L_E_X, FUN 47 looks to be Function block defined by user. T/C instruction look to not be for Omron or Mitsubishi... Do you know what is the original PLC? That will help us to guide you. Share this post Link to post Share on other sites
Posted 21 Apr 2016 The PLC is a S5 100u CPU 102 with 2 I/O units. The old unit was on Stop mode because it had a PEU error in ISTACK. We replaced the CPU and everything is fine, the green light is on, but no program is loaded. I made the steps to load the program from the EPROM (it's the memory with the UV window), but no valid program is loaded. The only things that are loaded are the arithmetic FBs (FB240 to FB251). Is it a special procedure to load the program from the EEPROM for CPU102 ? I don't have access to a Siemens programmer and i use PG2000 to connect to the PLC with a DIY RS232-TTY interface. The schematic was on the manual that came with the machine. When the new CPU came (SH unit bought from Ebay), i connected the memory module and i started the PLC. Next, i found a program in the PLC, but it doesn't look like the schematic from the manual. I saved the program and performed an overall reset and then a manual loading of the program from the memory module to the program memory, as it states in the manual. And now, only the arithmetic FB's are in the program memory. Is it possible that the program i found in the PLC to be from the old machine, even thought i connected the memory module before starting the PLC ? The program should have loaded from the memory module at PLC start ? Thank you. Share this post Link to post Share on other sites
Posted 21 Apr 2016 Hi A_L_EX, I am also Romanian. Please contact me on private for my phone number. Share this post Link to post Share on other sites
Posted 21 Apr 2016 Please check next sequence for PEU error. Share this post Link to post Share on other sites
