S7 Communication; Get And Put Instructions - Siemens SIMATIC S7-1200 Manual

7.8

S7 communication

7.8.1

GET and PUT instructions

You can use the GET and PUT instructions to communicate with S7 CPUs through
PROFINET and PROFIBUS connections. This is only possible if the "Permit access with
PUT/GET communication" function is activated for the partner CPU in the "Protection"
property of the local CPU properties:
● Accessing data in a remote CPU: An S7-1200 CPU can only use absolute addresses in
● Accessing data in a standard DB: An S7-1200 CPU can only use absolute addresses in
● Accessing data in an optimized DB: An S7-1200 CPU cannot access DB variables in an
● Accessing data in a local CPU: An S7-1200 CPU can use either absolute or symbolic
STEP 7 automatically creates the DB when you insert the instruction.
Note
To ensure data consistency, always evaluate when the operation has been completed
(NDR = 1 for GET, or DONE = 1 for PUT) before accessing the data or initiating another
read or write operation.
Note
V4.0 CPU program GET/PUT operation is not automatically enabled
A V3.0 CPU program GET/PUT operation is automatically enabled in a V4.0 CPU.
However, a V4.0 CPU program GET/PUT operation in a V4.0 CPU is not automatically
enabled. You must go the CPU "Device configuration", inspector window "Properties"tab,
"Protection" property to enable GET/PUT access (Page 82).
Easy Book
Manual, 03/2014, A5E02486774-AF
the ADDR_x input field to address variables of remote CPUs (S7-200/300/400/1200).
the ADDR_x input field to address DB variables in a standard DB of a remote S7 CPU.
optimized DB of a remote S7-1200 CPU.
addresses as inputs to the RD_x or SD_x input fields of the GET or PUT instruction,
respectively.
Easy to communicate between devices
7.8 S7 communication
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