I have started to work with codesys recently, on a Think IO-P plc. But i have many uncleared things that i haven't find in documentation. Hope the moderators can clarify some things for me.
1) Can i stop a POU and restart it later from the same step (in SFC)
2) with my plc i can't find the syslibtask library so i cannot work with tasks (suspend, resume). Think io does not support this?
3) How can i acces the online help?
4) Serial port functions does not work on plc, although the port seems to be opened
For the beginning i really hope someone can give help me with some answers.
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Usually in IEC SFC you work with actions. So you have to write the POU call from an action. In one step you can include the action with qualifier S and activate (start) it. In other step you can use the action with qualifier R and deactivate (stop) it. Moreover with qualifier SD you may activate the actions later in certain time.
If you need such behavior in one single step then you may program the POU calls inside the action with other language or with included SFC again.
Indeed it is extremely rare library and certainly not for beginners. Honestly I cannot think out a situation when I really need tasks administration in IEC programming practice. Probably you have to change the program decomposition strategy to exclude it.
'F1' does not work?
Sometimes the library SysLibCom do not work with some untypical configurations like 1.5 stop bit etc. Could you connect a terminal and control receiving and transmission separately with different settings? See attached example.
I have started to work with codesys recently, on a Think IO-P plc. But i have many uncleared things that i haven't find in documentation. Hope the moderators can clarify some things for me.
1) Can i stop a POU and restart it later from the same step (in SFC)
2) with my plc i can't find the syslibtask library so i cannot work with tasks (suspend, resume). Think io does not support this?
3) How can i acces the online help?
4) Serial port functions does not work on plc, although the port seems to be opened
For the beginning i really hope someone can give help me with some answers.
Hello
Some of your questions are hardware related and i think that Kontron could help you with this.
Send them a mail on e GSS@kontron.com e
Ok, but at least the first question is related to codesys i think.
Usually in IEC SFC you work with actions. So you have to write the POU call from an action. In one step you can include the action with qualifier S and activate (start) it. In other step you can use the action with qualifier R and deactivate (stop) it. Moreover with qualifier SD you may activate the actions later in certain time.
If you need such behavior in one single step then you may program the POU calls inside the action with other language or with included SFC again.
Indeed it is extremely rare library and certainly not for beginners. Honestly I cannot think out a situation when I really need tasks administration in IEC programming practice. Probably you have to change the program decomposition strategy to exclude it.
'F1' does not work?
Sometimes the library SysLibCom do not work with some untypical configurations like 1.5 stop bit etc. Could you connect a terminal and control receiving and transmission separately with different settings? See attached example.
RS232_Sender.pro [36.63 KiB]