Libraries   
9.4 Open user communication library 
  S7-200 SMART 
522  System Manual, V2.3, 07/2017, A5E03822230-AF 
This is an example usage of the UDP_RECV instruction: 
 
 
The DISCONNECT instruction terminates an existing communication connection. The 
DISCONNECT instruction is used for all protocols. 
 
 
LocPort, Done, Busy, Er-
ror, Status 
The DISCONNECT terminates an existing communication connec-
tion for all protocols. 
The DISCONNECT instruction initiates the connection termination when the program calls 
the DISCONNECT instruction with the Req input set TRUE. The Req input is level-triggered. 
It is recommended that you put a positive edge trigger on the Req input. 
If the requested connection (ConnID) is currently busy connecting, disconnecting, or cannot 
be found because the connection has been reused, the DISCONNECT instruction returns an 
error. 
The DISCONNECT instruction displays the Done or Error output status for at least one call 
of the instruction after the disconnect operation is complete. The instruction may return the 
status of the DISCONNECT instruction for the specified connection for subsequent calls until 
the CPU reuses the connection for another connect operation.