11/8/2010 9:16 AM | |
Joined: 9/3/2010 Last visit: 11/9/2023 Posts: 2 Rating:
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Hi, I have a problem with communication period on a Modbus link. There are 4 flowmeters Krohne and 8 frequency inverters Omron. The communication is set to 19200 kbits, no parity and a 1 stop bit. Thecommunication works OK but scan cycle for all equipments is about 10s - too long as I expected. Response timeout for MB_COMM_LOAD is set to 200ms andMessage timeout, Response timeout to 50ms and Inter-character gap timeout to 50 bit times (2.6ms).The settings and a screen copy of function codes are in the attachments. Cycle time for PLC is about 35ms and a maximum is 40ms. I checked the responses from the equipments by a oscilloscope andthe response times for all are about 10mson arequest from PLC. So the expected scan period should be less then 2s. Does anybody know what is wrong and how to shorten the time? Best regards Petr Čapek Czech Republic AttachmentAttachment.zip (179 Downloads) |
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