Lantronix XPort APS: Modbus Protocol User Guide - Page 33

10: Troubleshooting and Technical Support things hopelessly worse. If your OPC server or host application relies on pipelining to send more than one outstanding poll at once, then disabling the pipeline will essentially stop all data communication. (In which case, you can just turn the pipeline back on!)  The ideal solution (the 2nd generation solution) is for your Modbus/TCP master/client to not only support the Sequence Number, but also support the receipt of the 0x0A and 0x0B extended Modbus/TCP exception response. Then the master/client never needs to do retries - for each poll, it will receive either a value Modbus/TCP response or a Modbus/TCP exception that the slave is unreachable or timed out. This prevents the master/client from sending more polls than the IAP Device Server can process and building the TCP buffer queue up in the first place. Technical Support If you are experiencing an error that is not described in this chapter, or if you are unable to fix the error, you have the following options: Technical Support US Check our online knowledge base or send a question to Technical Support at http://www.lantronix.com/support. Phone: (800) 422-7044 (US Only) (949) 453-7198 Technical Support Europe, Middle East, and Africa Phone: +33 (0)1 39 30 41 72 +49 (0) 180 500 13 53 (Germany Only) Email: [email protected] or [email protected] Firmware downloads, FAQs, and the most up-to-date documentation are available at www.lantronix.com/support. When you report a problem, please provide the following information:  Your name, and your company name, address, and phone number  Lantronix model number and serial number  Software version (on the first screen shown when you Telnet to port 9999)  Description of the problem  Debug report (stack dump), if applicable  Status of the unit when the problem occurred (please try to include information on user and network activity at the time of the problem) Modbus Protocol User Guide 33