I need to implement a communication packets in a PLC program (LG PLC).
I intend to use a serie of ASCII text blocks and just drive them through the PLC's own serial port. These block will initiate a comunication link, imbed some data into it and then command an external device to do its thing.
What bugs me is that this device uses as CRC the CCITT-16 Reversed (0x8408) algorithm and it cannot be disable nor modified. (starting with FFFH)
Now I know that its a reverse XOR mask but its implementation in my PLC seem a bit painfull. And you know I'm not an advocate of pain. My moto is no pain... no pain
It will be much easyer when I will migrate to a microcontroler next year but now this must be done.
Any suggestion before I end up creating tons of lookup tables and get hooked on coffe and Dr Peper ???
This is similar to programming ones own feildbuss function block. Any one have done it in the past?
I intend to use a serie of ASCII text blocks and just drive them through the PLC's own serial port. These block will initiate a comunication link, imbed some data into it and then command an external device to do its thing.
What bugs me is that this device uses as CRC the CCITT-16 Reversed (0x8408) algorithm and it cannot be disable nor modified. (starting with FFFH)
Now I know that its a reverse XOR mask but its implementation in my PLC seem a bit painfull. And you know I'm not an advocate of pain. My moto is no pain... no pain
It will be much easyer when I will migrate to a microcontroler next year but now this must be done.
Any suggestion before I end up creating tons of lookup tables and get hooked on coffe and Dr Peper
???This is similar to programming ones own feildbuss function block. Any one have done it in the past?
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