Hi Pablo, Here is a really dumb suggestion ... You say the Master is Polling and the Slave is responding ... Have you checked what is actually coming from the slave (with a Modbus sniffer)? It is possible that what is being returned at each poll is an error message, rather than a data response ... Regards, Barry Heap Project & Shutdown Manager Direct: 03 9855 4057 Mobile: 0421 333 407 Fax: 03 9853 3734 Email: bheap@xxxxxxxxxxxx -----Original Message----- From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx] On Behalf Of Pablo Lioi Sent: Thursday, March 04, 2010 7:41 AM To: foxboro@xxxxxxxxxxxxx Subject: [foxboro] FD30B problem Hi List, I am having a strange problem with a FD30B to FD30B communication. My system consists of 6 FD30B "onshore" processors communicating via satellite link with 6 FD30B "offshore" processors (12 channels) At one "master" FD30B (onshore) I am getting all zero values at FDIIN blocks (same for both ports), while on the "slave" FD30B (offshore), the corresponding values are non-zero. Using a Modbus sniffer program on both ports of the "master" (onshore) FD30B, I was able to determine that: 1-The onshore FD30B is polling the offshore FD30B in accordance with the configured FDSCAN blocks. 2-The offshore FD30B is answering the polls in time and with non-zero values. 3-There are no CRC errors and no retries. Looking at the PERF counters of ports 0 and 1 of the onshore FD30B in Sysmon, I see that: 1-The number of transmitted messages matches the number of received messages. 2-The timeouts, checksum and sequence error counters stay at zero. In short, the onshore FD30B is polling, the offshore FD30B is responding, the onshore FD30B is accepting the responses, but values at the FDIIN blocks remain in zero. The database is configured as follows: 1-There is a compound for each FDSCAN block 2-For each FDSCAN block there are 8 FDIIN blocks in the same compound, reading (trying to read) 64 values from the FDSCAN. I have exactly the same configuration in the other 5 FD30B, and they are working OK. I believe the problem must be in the FDSCAN to FDIIN interface, but I found no error in the configuration of the FDIIN blocks. Of course, in a desperate attemp to solve things I: 1-Rebooted the onshore FD30B 2-Rebooted the offshore FD30B (yes, I know this had no logic) 3-Replaced the onshore FD30B (just in case) 4-Deleted/Undeleted a compound containing a FDSCAN block 5-Deleted a compound containing a FDSCAN block and re-wrote it from scratch. All to no effect. Any ideas? Regards Pablo Lioi TOTAL AUSTRAL S.A. Tierra del Fuego Argentina _________________________________________________________________ Mirá tus emails ¡cuando te llegan! Hotmail actualiza tu bandeja de entrada automáticamente. Ver más http://www.descubrewindowslive.com/hotmail/actualizacion-guardado.asp _______________________________________________________________________ This mailing list is neither sponsored nor endorsed by Invensys Process Systems (formerly The Foxboro Company). Use the info you obtain here at your own risks. Read http://www.thecassandraproject.org/disclaimer.html foxboro mailing list: //www.freelists.org/list/foxboro to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave ********************************************************************** This message contains privileged and confidential information intended only for the use of the addressee named above. If you are not the intended recipient of this message, you must not disseminate, copy or take any action in reliance on it. Any views expressed in this message are those of the individual sender, except where the sender specifically states them to be the views of Skilled Group Ltd. The sender cannot guarantee that this email or any attachment to it is free of computer viruses or other conditions which may damage or interfere with data, hardware or software with which it might be used. It is sent on the strict condition that the user carries out and relies on its own procedures for ensuring that its use will not interfere with the recipients systems and the recipient assumes all risk of use and absolves the sender of all responsibility for any consequence of its use. ********************************************************************** _______________________________________________________________________ This mailing list is neither sponsored nor endorsed by Invensys Process Systems (formerly The Foxboro Company). Use the info you obtain here at your own risks. Read http://www.thecassandraproject.org/disclaimer.html foxboro mailing list: //www.freelists.org/list/foxboro to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave