Siemens 1500 cpu TRCV_C error 809B

I am mystified as to what serialize/deserialize actually do.
It certainly looks like a complex way to get the same thing done.
Does serialize/deserialize take into account that the data gets shifted 1 byte in the middle of the structure ?
In the Siemens FAQ, the example merely shows data of different type but same size (WORD - INT).

For what I've used them for, Serialize/Deserialize take a UDT/Struct, and add it to an array (usually an array of bytes?), or remove that struct from the array. This is useful if you want to put a couple UDTs in one long array to send via TSEND.

HOWEVER, there's no magic there. It is literally taking the data and inserting it into the buffer, or removing data from the buffer and copying it into the UDT. If there are gaps in the UDT, it doesn't magically fix the data to make it fit. It assumes the data in the array already fits the UDT you want.

In a way, the commands are similar to the pitfalls of manually switching between symbolic and absolute programming.
 
Thats what I was getting from the Siemens FAQ. That it was just taking the data of a certain size and sending it to a byte array.
So it would basically do the same I would use an AT-view for. So it is when you dont want to or dont know how to use AT ?! It looks more confusing than just using AT. One for the "ignore" basket methinks.
 
Thats what I was getting from the Siemens FAQ. That it was just taking the data of a certain size and sending it to a byte array.
So it would basically do the same I would use an AT-view for. So it is when you dont want to or dont know how to use AT ?! It looks more confusing than just using AT. One for the "ignore" basket methinks.

I guess that could be one of its uses, but there's a big difference.

AT works on the data wherever it is (although last I heard it is of limited use in Optimized code). Whereas Serialize/Deserialize are more like a special block move. The key is that you can Serialize multiple UDTs into an array in one PLC, send it, and then Deserialize them in the other PLC into the respective UDTs. The commands automatically track where they are in the buffer, so you can keep appending data.
 

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