Siemens SIMATIC CP 440 Manual page 128

Diagnostics with the CP 440
Table 8-2 Event Classes and Event Numbers, continued
Event No.
(08)07H Impermissible message frame length:
A message frame of length 0 was received.
(08)08H With 3964(R) only:
Error in block check character (BCC)
Internally calculated value of BCC does not
match BCC received by partner at end of
connection.
(08)09H With 3964(R) only:
Waiting time for block repetition has
expired
(08)0AH There is no free receive buffer available:
No empty receive buffer was available to
receive the data.
(08)0CH Transmission error:
Transmission error (parity error, stop bit
error, overflow error) detected.
With 3964(R) only:
If a faulty character is received in idle
mode, the error is reported immediately
so that disturbances on the
transmission line can be detected early.
With 3964(R) only:
If this occurs during a send or receive
operation, repetitions are initiated.
(08)0DH BREAK:
The receive line to the partner is
interrupted.
(08)0EH Receive buffer overflow when flow control
not enabled.
(08)10H Parity error
8-10
Event
Point-to-point connection CP 440 Installation and Parameter Assignment
Remedy
Receipt of a message frame of length 0 is
not an error.
Check why the communication partner is
sending message frames without user data.
Check whether the connection is subject to
serious disturbances; in this case, you may
also occasionally see error codes. Identify
the malfunction on the partner device,
possibly by using an interface test device is
switched into the transmission line.
Parameterize the same block wait time in the
communication partner as for the CP 440.
Identify the malfunction in the
communication partner, possibly by using an
interface test device switched into the
transmission line.
The RECV_440 FB must be called more
frequently.
Disturbances on the transmission line cause
message frame repetitions, thus lowering
user data throughput. Danger of an
undetected error increases. Correct fault by
changing system setup or line installation.
Check the connecting cable of the
communication partners, or check whether
both devices have the same setting for the
transmission rate, parity and number of stop
bits.
Reestablish the connection, or switch the
partner on.
The function block to be received must be
called more often in the user program, or
communication with flow control must be
parameterized.
Check the connecting cable of the
communication partner, or check whether
both devices have same setting for the
transmission rate, parity and number of stop
bits.
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