Variables found in the WINCC interface are those in the DB block, but they cannot be found in the PLC; could such variables be those transmitted over communication?
Thread Content
Variables found in the WINCC interface are those in the DB block, but they cannot be found in the PLC; could such variables be those transmitted over communication?
What I mean is from other places, via communications such as Profibus or Modbus?
This post was last edited by jin-s-n on 2015-9-2 07:01. No, WINCC and the PLC are not compatible; this variable is useless. If it is transmitted through another communication method, check the connection
No, WinCC always has variables whose addresses come from the DB, and there must be a corresponding DB block in the PLC program. Check whether the Step7 program is linked to two or more PLCs, and look more carefully.
Unless this DB is an invalid item in WINCC (the manufacturer deleted it from STEP7 during initial debugging but not from WINCC), it must exist in STEP7. Also, is your STEP7 program identical to the program in the CPU?
Thank you to all the seniors! The programs for the host computer and the CPU should be identical. A few days ago, I added an alarm program, and the system crashed as a result. I checked the variables in STEP 7 using cross-referencing, but they weren’t there. There was also a strange phenomenon: for example, are there eight points in total, from I5.0 to I5.7? But it’s gone by I5.6; I also checked using cross-references, and I really don’t understand it. There are no jumps in the program to allow for such checks either – it’s truly baffling!