https://forge.codesys.com/forge/talk/Engineering/thread/8e5dd6e341/2020-02-27T13:51:38.904000ZRecent posts to Working with UDP packets.2020-02-27T13:51:38.904000Z2020-02-27T13:51:38.904000Ztimvhhttps://forge.codesys.com/u/timvh/https://forge.codesys.com9c499ecd9b33f67facb76851ff790066a9578632

<div class="markdown_content"><p>No, you don't need to have any "I/O" devices connected.</p></div>

2020-02-27T13:51:38.679000Z2020-02-27T13:51:38.679000Zfrankputnamjrhttps://forge.codesys.com/u/frankputnamjr/https://forge.codesys.com4234f563eb0ed004f81269739fb5d2a912aaa1bc

<div class="markdown_content"><p>Are the devices "Ethernet" and "EtherNet_IP_Scanner" required for the network connection? I had removed them Friday and it worked fine.</p></div>

2020-02-27T13:51:38.537000Z2020-02-27T13:51:38.537000Zfrankputnamjrhttps://forge.codesys.com/u/frankputnamjr/https://forge.codesys.com1693d037eef459fb1cf18e683b65a540d3ef91c3

<div class="markdown_content"><p>Thanks.</p> <p>Always use Wireshark when developing.</p> <p><img alt="IMG: Capture.JPG" rel="nofollow" src="https://forum.codesys.com//download/file.php?id=1175"/></p></div>

2020-02-27T13:51:38.393000Z2020-02-27T13:51:38.393000Ztimvhhttps://forge.codesys.com/u/timvh/https://forge.codesys.com042a1ff0a1472a753d2e70e65402b8313026b025

<div class="markdown_content"><p>You don't have to specify the ipAddr (IP_string) for the UDP peer receiver.<br/> It might work if you remove this input.</p></div>

2020-02-27T13:51:37.911000Z2020-02-27T13:51:37.911000Zfrankputnamjrhttps://forge.codesys.com/u/frankputnamjr/https://forge.codesys.combe49570f7c8e13fb049a2595b7018479e886e5fa

<div class="markdown_content"><p><img alt="IMG: Capture.JPG" rel="nofollow" src="https://forum.codesys.com//download/file.php?id=1173"/></p> <p><img alt="IMG: Capture1.JPG" rel="nofollow" src="https://forum.codesys.com//download/file.php?id=1174"/></p></div>

2020-02-27T13:51:37.767000Z2020-02-27T13:51:37.767000Ztimvhhttps://forge.codesys.com/u/timvh/https://forge.codesys.com6c78ae1ab7db117a30535782f484aa1ce98f1a13

<div class="markdown_content"><p>What I would do is:<br/> - Disable the firewall. When this is enabled, it might block incoming messages.<br/> - Install wireshark and check if the UDP packages are received. This will give you the general information if it is related to the PC/Network or CODESYS.</p></div>

2020-02-27T13:51:37.626000Z2020-02-27T13:51:37.626000Zfrankputnamjrhttps://forge.codesys.com/u/frankputnamjr/https://forge.codesys.com2f875728df5a5ebc0591ac0b668564691a66bf3d

<div class="markdown_content"><p>Friday the system was working perfectly. The messages came in and the valve indicators lit as requested.</p> <p>Monday and today I am no longer getting the messages into the program. </p> <p>When NBS.UDP_Peer is enabled the xActive goes true and hPeer has an address. There are no errors. xBusy stays true and xDone never goes active.</p> <p>NBS.UDP_Peer.xActive enables NBS.UDP_Receive. NBS.UDP_Peer.hPeer drives NBS.UDP_Receive.hPeer. There are no errors. xDone and xReady never go active and xBusy is always true. ipFrom, uiPortFrom, and szCount all report zero.</p> <p>Is there something missing?</p> <p><img alt="IMG: Capture.JPG" rel="nofollow" src="https://forum.codesys.com//download/file.php?id=1172"/></p></div>

2020-02-27T13:51:37.487000Z2020-02-27T13:51:37.487000Zfrankputnamjrhttps://forge.codesys.com/u/frankputnamjr/https://forge.codesys.com2201d3f81e9ef9d6753704c459a39f6581347005

<div class="markdown_content"><p>Tim,</p> <p>Thanks for the info. It works perfectly.</p> <p>The reason for UDP is a CAN to Ethernet converter. Using the CAN messages from the local controller to display information at the control cabin.</p></div>

2020-02-27T13:51:37.340000Z2020-02-27T13:51:37.340000Ztimvhhttps://forge.codesys.com/u/timvh/https://forge.codesys.com8ef972102b09a8d4e07f5705f8a766ba68c14767

<div class="markdown_content"><p>Add the "Use Case" library <span style="color: underline;">Network</span> to the library manager.<br/> See the screenshot for a simple example to receive UDP packages.</p> <p>If you are using this to communicate between 2 CODESYS controllers, then maybe you want to consider using Global Network Variables instead of UDP packages.</p> <p><img alt="IMG: ScreenShot.jpg" rel="nofollow" src="https://forum.codesys.com//download/file.php?id=1151"/></p></div>

2020-02-27T13:51:37.199000Z2020-02-27T13:51:37.199000Zfrankputnamjrhttps://forge.codesys.com/u/frankputnamjr/https://forge.codesys.com1b99301a1cc24c77901c669afc6c097679da781a

<div class="markdown_content"><p>I am trying to work with UDP packets in Codesys V3. Which library would be best for reading and writing UDP packets?</p></div>