Jump to content

Search the Community

Showing results for tags 'acknowledge'.



More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Forums

  • Software & Hardware Discussions
    • LabVIEW General
    • LabVIEW (By Category)
    • Hardware
  • Resources
    • LabVIEW Getting Started
    • OpenG
    • Code Repository (Certified)
    • LAVA Code on LabVIEW Tools Network
    • Code In-Development
  • Community
    • LAVA Lounge
    • LabVIEW Feedback for NI
    • LabVIEW Ecosystem
  • LAVA Site Related
    • Site Feedback & Support
    • Wiki Help

Categories

  • *Uncertified*
  • LabVIEW Tools Network Certified
  • LabVIEW API
    • VI Scripting
    • JKI Right-Click Framework Plugins
    • Quick Drop Plugins
    • XNodes
  • General
  • User Interface
    • X-Controls
  • LabVIEW IDE
    • Custom Probes
  • LabVIEW OOP
  • Database & File IO
  • Machine Vision & Imaging
  • Remote Control, Monitoring and the Internet
  • Hardware

Find results in...

Find results that contain...


Date Created

  • Start

    End


Last Updated

  • Start

    End


Filter by number of...

Joined

  • Start

    End


Group


Personal Website


Company Website


Twitter Name


LinkedIn Profile


Facebook Page


Location


Interests

Found 1 result

  1. I've been scratching my head with this one and am hoping someone has dealt with it before. My physical setup is a PC, CAT5 cables, a couple of switches, an Eaton HMI, and an Eaton PLC. I'm talking Modbus TCP to the PLC using the library on NI's website. I'm using Wireshark to troubleshoot other problems and found the PLC retransmitting the response to the PC very frequently (not every time). The PC is reads and writes 32 words to the PLC every 100 msec, but only performs a write when the data changes. The PLC transmits a response within 6 msec of a read message (function 3 in Modbus). The PC never responds with an acknowledgement of the message from the PLC. The PLC retransmits 50 msec later and the PC acknowledges that message. The write messages occur about every 1 second (my heartbeat to the PLC). I've tried switching to the second port on the PC, which goes to a second card in the PLC. That network has four drives, two air manifolds, a remote I/O block and an RFID system on it that are all talking to the PLC. The PLC sequences through all the remote devices, including the PC, so the response to the PC can take 75 - 150+ msec. The PC always acknowledges the first message with that network. Anyone have some thoughts as to what's going on? Tim Forgot to mention that I'm using LabVIEW 8.6.1 and have swapped all of the network components.
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.