5/3/2007 3:24 PM | |
Posts: 324 Rating:
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Hi, first of all I would upgrade the old CP 443-1 to the latest Firmware, this can be found at: CP 443 -1 Firmware Update V2.6 and Unrestricted Use in any Hardware Release (6GK7443-1EX10-0XE0 and 6GK7443-1EX11-0XE0) if this does not help we will furthermore. Stay calm. |
5/23/2007 10:48 AM | |
Posts: 14 Rating:
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Thank all of you for your comments and sorry for long time I need for answering. While I try different configurations: 1) I update all firmware with latest version : no visible effect 2) I change the parameter time reserved for communication from 20% to 50% : no visible effect 3) I set “minimal cycle time to 100ms: Communication time increase. waiting time is reserved for OB90 and can not be utilized for communication. 4) Modification of the send procedure. I only activate send if data change happened in the send DB: Transmission is fast for one single data change (< one change pro sec). In case of multiple changes, delays increase. It mean than a single transmission is fast but cycling communication not. 5) With a hub (unfortunately 10Mb/s) I capture communication with a analyzing software (Wireshark) : [code]|Time | 10.168.194.38 | 10.168.194.33 ||0.000 | 2003 > 2003 [ACK] S |TCP: 2003 > 2003 [ACK] Seq=0 Ack=0 Win=32 Len=0 | |(2003) ------------------> (2003) | |0.001 | 2003 > 2003 [PSH, A |TCP: 2003 > 2003 [PSH, ACK] Seq=0 Ack=0 Win=560 Len=32 | |(2003) <------------------ (2003) | |0.007 | [TCP ZeroWindow] 20 |TCP: [TCP ZeroWindow] 2003 > 2003 [PSH, ACK] Seq=0 Ack=32 Win=0 Len=32 | |(2003) ------------------> (2003) | |0.008 | [TCP ZeroWindowProb |TCP: [TCP ZeroWindowProbe] 2003 > 2003 [PSH, ACK] Seq=32 Ack=32 Win=528 Len=1 | |(2003) <------------------ (2003) | |0.009 | [TCP Window Update] |TCP: [TCP Window Update] 2003 > 2003 [ACK] Seq=32 Ack=32 Win=560 Len=0 | |(2003) <------------------ (2003) | |0.102 | [TCP Window Update] |TCP: [TCP Window Update] 2003 > 2003 [ACK] Seq=32 Ack=32 Win=32 Len=0 | |(2003) ------------------> (2003) | |0.103 | 2003 > 2003 [PSH, A |TCP: 2003 > 2003 [PSH, ACK] Seq=32 Ack=32 Win=560 Len=32 | |(2003) <------------------ (2003) | |0.107 | [TCP ZeroWindow] 20 |TCP: [TCP ZeroWindow] 2003 > 2003 [PSH, ACK] Seq=32 Ack=64 Win=0 Len=32 | |(2003) ------------------> (2003) | |0.108 | [TCP ZeroWindowProb |TCP: [TCP ZeroWindowProbe] 2003 > 2003 [PSH, ACK] Seq=64 Ack=64 Win=528 Len=1 | |(2003) <------------------ (2003) | |0.109 | [TCP Window Update] |TCP: [TCP Window Update] 2003 > 2003 [ACK] Seq=64 Ack=64 Win=560 Len=0 | |(2003) <------------------ (2003) | |0.204 | [TCP Window Update] |TCP: [TCP Window Update] 2003 > 2003 [ACK] Seq=64 Ack=64 Win=32 Len=0 | |(2003) ------------------> (2003) | |0.205 | 2003 > 2003 [PSH, A |TCP: 2003 > 2003 [PSH, ACK] Seq=64 Ack=64 Win=560 Len=32...[/code] Communication delay seems to be fast. I note that one partner give recurrently a windows size of 0 while 100ms. That may confirm what Smurf said. The CPU is not enough fast to eat all received data. Or maybe the communication between CPU and CP is slower than ethernet? Notice that fast communications is not as important as having predictable (soft real time) communication time. What should I do? Sincerely Rey Cyril Attachmentcaptures.zip (625 Downloads) |
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