TSPP error - buffer too small

[guschin]

Hello!

Some time ago made a test project with TSP protocol and it worked ok.
But now started it again and saw that values are not updating. Log viewer contains multiple messages:

Code: Select all

SEVERE,     35/s7, Buffer for unsolicited data too small

Can't understand what's wrong. What does this message mean?
BSEND block in PLC starts and finishes without errors. Data block's length for TSP protocol is 30 bytes.
WinCC OA v3.14p008 installed on Windows 7 Professional.

[Gertjan van Schijndel]

This message means that the received message size minus the TSPP header is smaller then two times the specified entire block length (or the received message cannot even contain the TSPP header).

So, in case of a 30 byte TSP message the length of the entire block should be 12 (or less).

[guschin]

Hello!

Sorry for long delay.

In my TSP message the entire block length is 12. Please have a look at screenshot of the datablock. Is it correct?
May this error (Buffer for unsolicited data too small) be caused by other reasons? https://www.winccoa.com/fileadmin/image ... ablock.png

[Gertjan van Schijndel]

The data block looks OK. Perhaps the data block is not completely sent. Could you verify that it is completely sent? With the debug flag 'DRV_USR1' (25), wireshark and/or the bsend block parameters?

[guschin]

Thank you for the reply.

Here is the output with the flag -dbg 25:

Code: Select all

WCCOAs7      (1), 2017.05.11 12:07:26.931, SYS,  INFO,      156, Driver initialization finished.
WCCOAs7      (1), 2017.05.11 12:07:27.181, SYS,  INFO,      156, Driver initialization finished., all items connected
WCCOAs7      (1), 2017.05.11 12:07:27.215, SYS,  INFO,        0, , S7Connection, generalQuery, Starting general query for connection:  CUB_TSPP
WCCOAs7      (1), 2017.05.11 12:07:27.415, SYS,  SEVERE,     35/s7, Buffer for unsolicited data too small
WCCOAs71:dump of S7 data: 
WCCOAs71:54 53 50 00 00 20 17 05 11 09 05 04 13 45 00 01 00 01 01 00 00 00 00 00 00 00 00 00 00 00 
WCCOAs7      (1), 2017.05.11 12:07:27.627, SYS,  SEVERE,     35/s7, Buffer for unsolicited data too small
WCCOAs7      (1), 2017.05.11 12:07:27.929, SYS,  SEVERE,     35/s7, Buffer for unsolicited data too small
WCCOAs71:dump of S7 data: 
WCCOAs71:54 53 50 00 00 20 17 05 11 09 05 04 13 45 00 01 00 01 01 00 00 00 00 00 00 00 00 00 00 00 
WCCOAs71:dump of S7 data: 
WCCOAs71:54 53 50 00 00 20 17 05 11 09 05 05 13 45 00 01 00 01 00 00 00 00 00 00 00 00 00 00 00 00 
WCCOAs7      (1), 2017.05.11 12:07:28.231, SYS,  SEVERE,     35/s7, Buffer for unsolicited data too small
WCCOAs71:dump of S7 data: 
WCCOAs71:54 53 50 00 00 20 17 05 11 09 05 05 13 45 00 01 00 01 00 00 00 00 00 00 00 00 00 00 00 00 
WCCOAs7      (1), 2017.05.11 12:07:28.533, SYS,  SEVERE,     35/s7, Buffer for unsolicited data too small
WCCOAs7      (1), 2017.05.11 12:07:28.835, SYS,  SEVERE,     35/s7, Buffer for unsolicited data too small

Also please have a look at BSEND parameters and screenshot of Wireshark output. It seems that it returns an error. https://www.winccoa.com/fileadmin/image ... eshark.png

[Gertjan van Schijndel]

The received message is not correct as indicated by the error message:
Header: TSP -> OK
Record length: 0 -> No values, but should be 6 according to your datablock image. However is OK for an alive message.
Length of entire block: 32 (0020h) -> NOK, should be 12 to match the message length.

[guschin]

Thank you, the problem was solved! Somehow wrong parameters were written to the block during runtime.

One more question concerning TSP protocol. BSEND function block has parameter R_ID that should be the same on the receive side. But there is no related setting in WinCC OA. Does this mean that R_ID should always be 1 and there could be only one BSEND telegram?

[Gertjan van Schijndel]

The R_ID parameter is not used in the S7 driver, it should accept all values for it.