My PLC is sending a message on Ethernet to a gateway with known good index information and the device on the slave side is on-line. Yet I receive an exception response. What could be happening?



One of two possibilities. Either the gateway has exhausted all available TCP sockets on the Ethernet side, or the internal buffer that may share memory for messages on both sides is full and cannot accept any more requests. Consider either time staggering requests to the bridge or adding an additional bridge to segregate communications traffic.