Communication Connections Checklist - Siemens SIMATIC NET S7-300 Manual

8.6.2

Communication Connections Checklist

Table 8-6 Checklist for Typical Problems with ISO Transport / ISO-on-TCP / UDP Connections
Problem
No data transfer on an
ISO transport connection
/
ISO-on-TCP connection
or only in one direction.
Data transfer too slow
The complete data field
is not sent on an ISO
transport /
ISO-on-TCP/UDP
connection.
The complete data field
is not sent on an ISO
transport /
ISO-on-TCP/UDP
connection.
S7-CPs for Industrial Ethernet Configuring and Commissioning
Release 01/2007
C79000-G8976-C182-07
Possible Cause
AG-SEND and AG-RECV
are not called in the user
program.
or
Receive or send buffer too
small or incorrect.
The connection is not
established.
Receiving device too slow
LEN parameter for
AG-SEND is set to the
wrong value.
The buffer specified with
the ANY pointer is too
small.
8 NCM S7 Diagnostics
Identifying the Cause and Remedy
Check the user program.
Evaluate status bytes in AG-SEND and
AG-RECV.
What to do:
If necessary, configure FC blocks.
If necessary, correct ANY pointer.
Evaluate status bytes of the FC blocks or
evaluate diagnostic buffer.
What to do:
Change the address parameters (MAC/IP
address, TSAP).
Evaluate diagnostic buffer.
Entry: "No receive resources on destination
station XX".
What to do:
Delay the send trigger or check the destination
station and optimize reception.
What to do:
Set the LEN parameter to the required size.
What to do:
Correct the LEN parameter and the ANY pointer.
A -281