Tins (Customer) asked a question.
Click plc receive and send command
Dear all I am shifting from microcontroller to plc. In microcontroller you can send and receive rs232 message independently. For example you can continously sendout while waiting for incomming. But in click plc this doesnt seem possible. It means you cant wait incoming while sendinout if the receiving command is engaged in checking inputs it doesnt seems possible to sendout. How could I solve this?
You would need to interlock the Receive/Send instructions. The RS232 is not full duplex.( can't receive and send at the same time.) See the user manual Chapter 4 starting on page 4-31.
https://cdn.automationdirect.com/static/manuals/c0userm/ch4.pdf
https://accautomation.ca/click-plc-send-and-receive-instructions/
The above is an example of the Click send and receive instruction.
The entire series can be found here:
https://accautomation.ca/series/click-plc/
This may help you out.
Regards,
Garry
Depending on ones requirements, one might consider a more expensive PLC that buffers the coms (e.g. Do-more). The RS232 spec. does allow full duplex (there are separate wires for transmit and receive) but the CLICK does not implement that ability.
It doesn't necessarily have to be a more expensive PLC.
The P1K with at least V1.10.0.11 supports full duplex:
6.) Full Duplex is now supported on the RS 232 port and will now have the option of Half Duplex or Full Duplex when in ASCII/ Custom Protocol mode. Full Duplex allows the serial port to transmit and receive simultaneously
Thank you all. Execuse me for being late.
Therefore it is the plc nature it is not full duplex like most microcontroller. So i will follow a technic that handle the situation as given by ADC_community_01.