Siemens SIMATIC S7 System Manual page 523

After the DISCONNECT instruction completes a disconnect, if the program calls the
DISCONNECT instruction with Req set FALSE, the instruction returns error code 24, which
means no operation pending.
Table 9- 21
Parameter
EN
Req
ConnID
Done
Busy
Error
Status
Exampled
This is an example usage of the DISCONNECT instruction:
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
Parameters of the DISCONNECT instruction
Declaration Data type
IN BOOL
IN BOOL
IN WORD
OUT BOOL
OUT BOOL
OUT BOOL
OUT BYTE
9.4 Open user communication library
Description
Enable input
The CPU starts the disconnect operation if Req =
TRUE.
The CPU uses the Connection ID (ConnID) num-
ber to identify the connection to be terminated
(defined during the connect process).
The instruction sets the Done output when the
disconnect operation is complete with no errors.
The instruction sets the Busy output while the
disconnect operation is in progress.
The instruction sets the Error output when the
disconnect operation is complete with an error.
Refer to "Open user communication library in-
struction error codes" (Page 524) for further in-
formation.
The Status output shows the error code if the
instruction sets the Error output. Status is zero
(no error) if the instruction sets the Busy or Done
outputs.
Libraries
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