Hello,

this depends probably to exact selected comm driver on HMI side with PLC system used. If you want some better support from Forum, describe pls better what exactly HW you have and what problem you have, also what is working to you to have better look at your problem.

Maybe problem is with specific data type from 3-rd party HW PLC what Siemens HW doesn't support, I mean as defined data type with this driver transport. Therefore I see probably that some workaround with other data type is only solution. On other side, it is maybe possible that use of Array of specific data type can be used here. Next problem is Optimized access to data block, who knows what you really do or want to use.