Question on Messaging

Hello,

what is the difference between plc5 typed write and plc2 unprotected write? And can someone explain to me how messaging works in plc? I get confused with tags because a message tag has a source element which is also a tag?

thanks for any clarifications received.

I'm sorry, but I couldn't understand your questions. Could you use some other words, or try to explain what you mean?

The PLC5's memory is split up into files of different data types (Floats, Integers, Booleans, etc.) while the PLC2's memory is just one flat address space. So a PLC5 typed write will write to a file with the appropriate data type. A PLC2 unprotected write simply writes to a specific address without regard for how it is used (i.e. Integer, BCD, Timer, etc.)

For both styles of write message, the source is the address of the data in *this* PLC that you want to write into the destination address in *that* PLC (identified by a DH+ node number).

I wouldn't recommend a PLC2 unprotected write unless it is an existing system that is already working that way or you are actually writing from a PLC2. If the processor the message instruction is going to execute in is a PLC5, definitely use the PLC5 typed write instead.