Post by winki on ModbusFB ClientRequest: never recovers after a single ReplyTimeout (requires full download) ^{CODESYS Forge talk (Post)}
Library: ModbusFB (CODESYS Modbus package) IDE / Runtime: CODESYS V3.5 SP___ / Control runtime ___ Target: ___ (e.g. gateway, Linux ARM64 / Debian) Slave: Modbus TCP inverter Summary I poll a Modbus TCP slave with a permanent connection: one ClientTCP (kept connected, xConnect:=TRUE) and one ClientRequestReadHoldingRegisters, triggered cyclically. Everything works fine after a fresh application download. But as soon as one single ReplyTimeout occurs (slave temporarily not answering), the request never recovers. It stays stuck and no further messages are sent, even though the TCP connection is still reported as alive. Only a full application download brings it back — an online change or a runtime reset is not enough / not what I want in production. State observed when stuck So the connection is alive, the request finished in ReplyTimeout, the FB is back to _state = None, but udiNumMsgSent no longer increases — as if a new rising edge on xExecute is no longer accepted / no longer produces a new message. My trigger logic (simplified) Each PLC cycle, in this order: If the request is fully at rest (NOT xExecute AND NOT xBusy AND NOT xDone AND NOT xError) and a read is pending, I set xExecute := TRUE. I call clientTcp() then clientRequest(rClient := clientTcp) once each, per cycle. On xDone or xError, I set xExecute := FALSE. I made sure to insert at least one full cycle with xExecute = FALSE (seen by the FB call) before re-triggering, so the falling edge is processed. Questions After a ReplyTimeout (xError = TRUE), what is the exact, correct sequence to re-trigger the same ClientRequest so a new message is actually sent again? Is a full cycle with xExecute = FALSE between two executions mandatory? Is there a known condition where, after ReplyTimeout, the ClientTCP keeps xConnected = TRUE but silently stops sending new requests (e.g. an internal request queue / _udiRequestId that gets out of sync)? udiNumMsgSent freezing at 23 while the FB shows _state = None is what puzzles me. Is the recommended pattern to drop the connection (ClientTCP.xConnect := FALSE for one cycle, then TRUE) on a request error, rather than keeping it alive? The docs state a request error does not close the connection, so I kept it open — but maybe that is the issue here. Could the large uiStartItem (50514) be relevant? It works right after download, so addressing seems correct, but I want to rule it out. Any guidance on the canonical recovery pattern after a request timeout would be greatly appreciated. Thanks!
Last updated: 2026-06-19

Post by hhermsen on Codesys v3.5.22.10 - Internal error:System.AggregateException...Value cannot be null...Parameter name: expLValue ^{CODESYS Forge talk (Post)}
Internal compiler error in SP22.x (expLValue null) — SP21 unaffected — need help isolating root cause I'm hitting the same internal compiler crash reported here. Same exact stack trace (AssignmentStatementReplacer → CreateAssignmentExpression → ArgumentNullException: Value cannot be null. Parameter name: expLValue), but in my case triggered by a self-written library, not a Visualization object — so this looks like a general SP22.x codegen regression rather than something tied to one specific language feature. What I've confirmed: Reverting to SP21 — no issue, builds clean SP22.x — internal compiler crash during Build > Application, code generation phase, with zero useful location info (no POU, no line number) check_for_errors/precompile-only passes cleanly; the crash only happens on a real full build, meaning static analysis never sees it coming What I've tried to isolate the cause (without success): Removed a suspected pattern involving a VAR_IN_OUT parameter used directly as a FOR-loop control variable, combined with early RETURN inside the loop — crash persisted identically afterward Confirmed no Visualization Manager or similar object in the project (ruling out the trigger in the linked report) Used an AI coding assistant (Claude Code) to search for other suspicious patterns — no luck pinpointing the exact statement Question @codesys-com Since the compiler gives no location info at all, is there any way to get more diagnostic output from the SP22.x codegen phase (verbose/debug build flags, log level settings, etc.)? Without that, isolating this in a large library means blind bisection — cutting the codebase in half repeatedly until the crash disappears, which is slow and error-prone without official tooling support. Happy to share the affected project or a minimal repro if that helps CODESYS engineering track it down.
Last updated: 2026-07-11

Post by felixal on Codesys automatic Data transfer to USB on rasberry pi ^{CODESYS Forge talk (Post)}
Hi all, I am currently working on a project where I need to save data automatically on many diffrent USB-Sticks, which are always plugged in the same USB-Port on a Rasberry PI, but I do not get how I can automatically detect the USB devices Folder Name and save a file there on Linux. Thanks!
Last updated: 2024-01-03

Post by spiessli on Raspberry Pi 4 with Legacy Drivers and Codesys 3.5.19 Patch 4 ^{CODESYS Forge talk (Post)}
Thanks for the suggestion, I have tried it eagerly: I have updated all packages to latest version with Codesys Installer and installed newest runtime and gateway on Raspberry Pi. Unfortunately, the error is still there. As soon as I add the SM_Drive_Servo to the device tree, I get the error below when generating the code. Reverting SM3_Basic to version 4.14 makes the error disappear. ------ Übersetzungslauf gestartet: Applikation: Device.Application ------- Code typisieren... Code erzeugen... [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0032: Typ 'Unbekannter Typ: 'ConfigGetParameterValueLREAL(pParam, 0)'' kann nicht in Typ 'LREAL' konvertiert werden [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0046: Bezeichner 'ConfigGetParameterValueLREAL' nicht definiert [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0035: Programmname, Funktion oder Funktionsbausteinstanz an Stelle von 'ConfigGetParameterValueLREAL' erwartet [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0032: Typ 'Unbekannter Typ: 'ConfigGetParameterValueLREAL(pParam, 0)'' kann nicht in Typ 'LREAL' konvertiert werden [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0046: Bezeichner 'ConfigGetParameterValueLREAL' nicht definiert [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0035: Programmname, Funktion oder Funktionsbausteinstanz an Stelle von 'ConfigGetParameterValueLREAL' erwartet [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0032: Typ 'Unbekannter Typ: 'ConfigGetParameterValueLREAL(pParam, 0)'' kann nicht in Typ 'LREAL' konvertiert werden [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0046: Bezeichner 'ConfigGetParameterValueLREAL' nicht definiert [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0035: Programmname, Funktion oder Funktionsbausteinstanz an Stelle von 'ConfigGetParameterValueLREAL' erwartet [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0032: Typ 'Unbekannter Typ: 'ConfigGetParameterValueLREAL(pParam, 0)'' kann nicht in Typ 'LREAL' konvertiert werden [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0046: Bezeichner 'ConfigGetParameterValueLREAL' nicht definiert [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0035: Programmname, Funktion oder Funktionsbausteinstanz an Stelle von 'ConfigGetParameterValueLREAL' erwartet [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0032: Typ 'Unbekannter Typ: 'ConfigGetParameterValueLREAL(pParam, 0)'' kann nicht in Typ 'LREAL' konvertiert werden [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0046: Bezeichner 'ConfigGetParameterValueLREAL' nicht definiert [FEHLER] sm3_drive_servo, 4.10.0.0 (codesys): GetStandardConfigParams [AXIS_REF_SERVO]: C0035: Programmname, Funktion oder Funktionsbausteinstanz an Stelle von 'ConfigGetParameterValueLREAL' erwartet Übersetzung abgeschlossen -- 15 Fehler, 0 Warnungen : Kein Download möglich
Last updated: 2023-12-20

Two drives on one axis, Gantry Robot ^{CODESYS Forge talk (Thread)}
Two drives on one axis, Gantry Robot
Last updated: 2023-08-25

Problems connecting to Codesys 4.9.0.0 runtime on my Wago PFC200 ^{CODESYS Forge talk (Thread)}
Problems connecting to Codesys 4.9.0.0 runtime on my Wago PFC200
Last updated: 2023-08-26

Post by timvh on gateway problem ^{CODESYS Forge talk (Post)}
Maybe select the local gateway instead of the gateway on the remote device?
Last updated: 2023-08-31

Ranges, Lambdas, on Fixed arrays of structs ^{CODESYS Forge talk (Thread)}
Ranges, Lambdas, on Fixed arrays of structs
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Introductory short video series on PLC programming (CODESYS) ^{CODESYS Forge talk (Thread)}
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Last updated: 2023-08-28

Post by eschwellinger on Code Size ^{CODESYS Forge talk (Post)}
will start with next relaese on RTE, at the moment not possible.
Last updated: 2023-09-08

Post by eschwellinger on SPI Master not running/MCP3008 Missing driver. ^{CODESYS Forge talk (Post)}
SPI enabled on 'sudo raspi-config' reduce _diMaxSpeed
Last updated: 2023-09-12

Network Variable List in Codesys 3.5 on CAN ^{CODESYS Forge talk (Thread)}
Network Variable List in Codesys 3.5 on CAN
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Cannot install library "mail service" on SP17 ^{CODESYS Forge talk (Thread)}
Cannot install library "mail service" on SP17
Last updated: 2021-12-22

Making changes to ENI controlled code on site ^{CODESYS Forge talk (Thread)}
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Last updated: 2011-05-04

Ged rid of lines on Chart XY ^{CODESYS Forge talk (Thread)}
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Last updated: 2022-04-05

Where do I find documentation on the libaries in V3.3 ? ^{CODESYS Forge talk (Thread)}
Where do I find documentation on the libaries in V3.3 ?
Last updated: 2010-02-08

Adding a CANBUS device on Codesys Control Linux SL ^{CODESYS Forge talk (Thread)}
Adding a CANBUS device on Codesys Control Linux SL
Last updated: 2022-05-25

How to have a persistent var on raspberry ? ^{CODESYS Forge talk (Thread)}
How to have a persistent var on raspberry ?
Last updated: 2018-01-03

Disable Codesys communication on fieldbus ethernet card ^{CODESYS Forge talk (Thread)}
Disable Codesys communication on fieldbus ethernet card
Last updated: 2022-06-13

modbus RTU on ControlWin softplc: disable RTS DTR ^{CODESYS Forge talk (Thread)}
modbus RTU on ControlWin softplc: disable RTS DTR
Last updated: 2020-03-26

New to CANopen on EASY215.Help required. ^{CODESYS Forge talk (Thread)}
New to CANopen on EASY215.Help required.
Last updated: 2009-01-15

Post by callumo1 on Check For Open Dialogs On Client ^{CODESYS Forge talk (Post)}
Okay, Thanks for the help
Last updated: 2023-09-26

Post by sukrit on What licenses are required for runtime on raspberry pi cm4 ^{CODESYS Forge talk (Post)}
attached is the software matrics
Last updated: 2023-10-17

What licenses are required for runtime on raspberry pi cm4 ^{CODESYS Forge talk (Thread)}
What licenses are required for runtime on raspberry pi cm4
Last updated: 2023-10-17

CODESYS Control for Raspberry Pi SL on Raspberry Pi 4b ^{CODESYS Forge talk (Thread)}
CODESYS Control for Raspberry Pi SL on Raspberry Pi 4b
Last updated: 2023-10-17

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