Post by maldus512 on How to adapt Codesys Control SL to custom board ^{CODESYS Forge talk (Post)}
Hello everyone, I have been given the task to develop I/O drivers for a custom made, Linux based board to allow for Codesys applications to run and control the hardware. I have successfully installed Codesys Control SL for ARM/Linux and tested it with a simple demo application. Now I should start interfacing the runtime to the actual hardware; I should be able to interact with 2 RS485 serial ports, a few GPIOs and an I2C port, all of which already have the corresponding /dev/ interface in the Linux system. I am having trouble understanding how it should be approached. I have found sporadic references that fail to lead to a really comprehensive documentation. For example: The store page (https://store.codesys.com/en/codesys-control-for-linux-arm-sl-1.html#options) mentions a "runtime package" that should allow "Integration of existing C code" and "Usage of local I/Os", which seems exactly what I need to interact with custom peripherals. I have found no further reference to Codesys-C interpop. The Codesys Help page for the runtime package has a page on the "Development of Drivers" (https://content.helpme-codesys.com/en/CODESYS%20Control/rtsllinuxrbpdriverdevelopment.html) that suggests to either "Implement a function block" or "Implement I/O drivers". Those in turn lead to this page (https://forge.codesys.com/drv/io-drivers/doc/Generic/) which describes briefly an XML schema to describe new devices; unfortunately, it doesn't mention what to do with such a description (i.e. how does the runtime know about it) or how it is in any way connected to the actual hardware. Could anyone give me some pointers? I should also mention I have no prior experience with Codesys, so maybe I'm missing an obvious answer.
Last updated: 2024-08-09

Post by testlogic on Sending Sequential Modbus TCP Packets ^{CODESYS Forge talk (Post)}
I have a Modbus TCP slave device where I need to do sequential writes to the same register. The register I'm writing to is kind of like a command line, each packet is a command word encoded in Hexadecimal. I am having difficulty implementing this system in CoDeSys 3.5 SP19. I feel like the structure of the program should be something along the lines of (Pseudocode): ModbusTCPSend(Command Register, Command1) ModbusTCPSend(Command Register, Command2) ModbusTCPSend(Command Register, Command3) I have tried to implement this with a rising edge trigger wMot1OPCode := 16#E1; //Stop Motor & Kill Program xMot1SendOP := TRUE; //Send OP on rising edge xMot1SendOP := FALSE; //Reset wMot1OPCode := 16#9E; //Disable Motor xMot1SendOP :=TRUE; //Send OP on rising edge xMot1SendOP := FALSE; //Reset Where "wMot1OPCode" is the IO map for writing to the command register, and "xMot1SendOP" is the rising edge trigger for that modbus channel. However, this doesn't work. The device never responds to the modbus commands. It seems like the trigger variable is switched too quickly for modbus to send the packet. I know the modbus register is working, because I can set the channel to cyclic and the device will respond. However, I can't use this reliably because I need each command to be sent once, in order. Cyclic keeps re-sending the commands and seems like it could miss a command as well if one was sent in-between cycle time. I have also trying using the Application trigger as described by https://faq.codesys.com/pages/viewpage.action?pageId=24510480, but this is also not working for me. See attached picture for my FBD code. This seems like a simple function, I can't tell what I'm doing wrong here. Thanks for the help.
Last updated: 2024-03-06

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