'keep last value' option in CODESYS EtherCAT ^{CODESYS Forge talk (Thread)}
'keep last value' option in CODESYS EtherCAT
Last updated: 2025-11-18

Error while using Codesys SP19 Patch 4 on Windows 11 ^{CODESYS Forge talk (Thread)}
Error while using Codesys SP19 Patch 4 on Windows 11
Last updated: 2025-11-27

Non-formal invocation of function blocks in CODESYS ^{CODESYS Forge talk (Thread)}
Non-formal invocation of function blocks in CODESYS
Last updated: 2025-12-04

Non-formal invocation of function blocks in CODESYS ^{CODESYS Forge talk (Thread)}
Non-formal invocation of function blocks in CODESYS
Last updated: 2025-12-05

CODESYS OPC UA Security: HMI Client Not Receiving Server Certificate ^{CODESYS Forge talk (Thread)}
CODESYS OPC UA Security: HMI Client Not Receiving Server Certificate
Last updated: 2026-01-06

CODESYS OPC UA Security: HMI Client Not Receiving Server Certificate ^{CODESYS Forge talk (Thread)}
CODESYS OPC UA Security: HMI Client Not Receiving Server Certificate
Last updated: 2026-01-06

Unresolved reference when trying to upload to Codesys Runtime V3 ^{CODESYS Forge talk (Thread)}
Unresolved reference when trying to upload to Codesys Runtime V3
Last updated: 2026-03-25

Codesys v3.5.22.10 - Fail to create a project Archive ^{CODESYS Forge talk (Thread)}
Codesys v3.5.22.10 - Fail to create a project Archive
Last updated: 7 days ago

Codesys 3.5.21.3 add Library search not work ^{CODESYS Forge talk (Thread)}
Codesys 3.5.21.3 add Library search not work
Last updated: 2026-01-20

Codesys EtherCAT Driver (CmpEt1000MPD) can't set MAC address ^{CODESYS Forge talk (Thread)}
Codesys EtherCAT Driver (CmpEt1000MPD) can't set MAC address
Last updated: 2026-02-09

Unit testing support / libraries for EcoStruxure Machine Expert (CODESYS) ^{CODESYS Forge talk (Thread)}
Unit testing support / libraries for EcoStruxure Machine Expert (CODESYS)
Last updated: 2026-02-20

How to use MQTT in CODESYS Control Win V3 ^{CODESYS Forge talk (Thread)}
How to use MQTT in CODESYS Control Win V3
Last updated: 2026-02-25

Fail communication between CODESYS and Fuxa SCADA via OPC UA ^{CODESYS Forge talk (Thread)}
Fail communication between CODESYS and Fuxa SCADA via OPC UA
Last updated: 2026-03-12

RS232 Communication in CODESYS Control RTE V3 ^{CODESYS Forge talk (Thread)}
RS232 Communication in CODESYS Control RTE V3
Last updated: 2026-03-14

CODESYS device discovery performance in large networks (/16) ^{CODESYS Forge talk (Thread)}
CODESYS device discovery performance in large networks (/16)
Last updated: 2026-03-29

Codesys Installation Always Freeze when the installing is almost done ^{CODESYS Forge talk (Thread)}
Codesys Installation Always Freeze when the installing is almost done
Last updated: 2026-04-05

file library ifm CR2033 .lib in the CODESYS v2.3 ^{CODESYS Forge talk (Thread)}
file library ifm CR2033 .lib in the CODESYS v2.3
Last updated: 2026-04-22

Deploy Codesys Control SL to a 'secure' device ^{CODESYS Forge talk (Thread)}
Deploy Codesys Control SL to a 'secure' device
Last updated: 2 days ago

Post by artplc on 3.5 P20 hangs - no response ^{CODESYS Forge talk (Post)}
Subject: Solution: CODESYS Freezes Linked to Large Symbol Configuration (OPC UA) Hello everyone, I was experiencing the same problem as many here: CODESYS (v3.5 SP20+) freezing during compilation and download, especially on projects that use OPC UA for SCADA. The only workaround was to run Build > Clean all before every download. I believe I have found the root cause and a permanent solution. The Problem: The issue is directly related to a large Symbol Configuration. In my project, I only need about 700 tags for OPC UA, but the Symbol Configuration list was showing over 250,000 tags. This is because it automatically includes all variables from Global Variable Lists (GVLs) and other memory areas. When any static variable is changed, the IDE tries to rebuild this enormous list, causing it to freeze for several minutes. The Solution: Instead of letting CODESYS export every variable by default, you can use a pragma to tell it which variables or GVLs to exclude from the symbol export process. Place the following pragma at the top of any GVL or data structure that you do not want to be part of the symbol configuration: 1 {attribute 'symbol' := 'none'} 2 VAR_GLOBAL 3 // All variables in this GVL will now be excluded from the 4 // Symbol Configuration by default. 5 InternalVariable1 : INT; 6 InternalVariable2 : BOOL; 7 END_VAR After adding this pragma to all the GVLs that were not needed for OPC UA, the number of tags in my Symbol Configuration dropped to the correct amount. The compilation and download process is now fast again, with no freezing. This method is much more efficient than manually managing the symbol list in the editor. I hope this helps others who are facing this frustrating issue. Best regards.
Last updated: 2025-08-10

Post by thierry-b on Blocking UDP ports 1740–1743 and 22350 to disable CODESYS network scan (startup + device discovery) ^{CODESYS Forge talk (Post)}
Hello, I am currently investigating the network behavior of CODESYS 3.5 (IDE + Gateway) in environments where the engineering workstation is connected to a very large /16 network. In such networks, the automatic device scan performed at IDE startup (and the manual “Scan Network” device discovery) can cause significant delays or freezes, due to the broadcast‑based discovery mechanism. After analyzing the traffic with Wireshark, I identified that the IDE uses the following UDP ports: 1740 – broadcast discovery 1741 – handshake / responses 1742 – fallback discovery 1743 – fallback handshake 22350 – additional runtime / gateway communication (WAGO, debug, extended discovery) To prevent the IDE from scanning the large /16 network, I tested blocking these ports in both directions (IN/OUT) on the network interface connected to the /16 segment (while keeping them open on the OT /24 network interface). Result: When UDP 1740, 1741, 1742 and 1743 are blocked on the IT interface, the IDE no longer sends any discovery traffic on that interface. The IDE still works normally on the OT interface (device discovery, online mode, download, etc.). Blocking port 22350 does not seem required to stop the scan, but I included it for completeness. My question: => Can you confirm that blocking UDP ports 1740, 1741, 1742, 1743 (and optionally 22350) on a specific network interface is a valid and supported way to completely disable the CODESYS IDE network scan on that interface (both at startup and during manual device discovery)? I am not trying to block communication with controllers on the OT network — only to prevent the IDE from scanning the large /16 IT network. Any confirmation or additional technical details about the discovery mechanism would be greatly appreciated. Thank you.
Last updated: 2026-03-31

communication ^{CODESYS Forge talk (Thread)}
communication
Last updated: 2023-08-19

NETVAR_UDP ^{CODESYS Forge talk (Thread)}
NETVAR_UDP
Last updated: 2023-08-29

VPN ^{CODESYS Forge talk (Thread)}
VPN
Last updated: 2023-09-06

VPN ^{CODESYS Forge talk (Thread)}
VPN
Last updated: 2023-09-06

VPN ^{CODESYS Forge talk (Thread)}
VPN
Last updated: 2023-09-06

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