Serial communication with KINCO PLC

[francisco]

Hello to everyone. Nice to meet you all.



I am programming a KINCO PLC model HP043-20DT using ladder on KINCO BUILDER. I need to establish a serial communication with my PC. The PLC has a RS485 port which I adapted it to USB to connect with my PC. The PLC allows, at least, two ways to establish serial communication: MODBUS or free-protocol. I've read the software manual and tried to reproduce the examples it provides using the instruction blocks for MODBUS (MBUSR and MBUSW) and free-protocol (XMT and RCV) communications. However, I could not receive the data on the PLC. I could effectively transmit data with XMT from the PLC to the PC and I could verify through a tool called Access Port. In relation to MODBUS, I am using a simulation tool called Multiway from OMRON, however, I get no response from the PLC.



If any of you have some experience with this software or this device, I would like to ask you how could I solve the problem.



Thank you for your attention. Kind regards.

[Admin]

Hi Francisco: I never had experience with that brand (Kinco), but we see a common problem within your question, that my insight may help. Or may not, but here it is anyway.

With AB/Rockwell PLCs, they made serial connection supper easy. 1 click of a button and their communication software (RSLinx) tries every possible setting for RS232 communication until it successfully establishes communication and sets everything up for you.

Yet even that brand is the easiest to work with out of all brands when a new user to using a USB to RS232 converter, gets stuck with failure to communicate. What they overlook, is each time you plug in a converter cable to your USB, your computer picks a random port number not already being used on your computer. The user of the AB PLC/RSLinx communication software has to look up what comm port number the computer/USB to RS232 software picked for the converter. Then they have to open the RSLinx PLC communication software and change the port number of the RS232 driver within, to match the port number used by USB/RS232 converter software. Then RSLink can automatically detect all the rest of the communication settings (IE: baud rate, parity, etc., etc.). So you may want to check if a similar problem is occurring with your setup.

So check:

* Comm port number in communication software is the same as comm port number in USB/RS232 converter.
* Check that all RS232 settings in the Software are the same as set in the PLC you are wanting to communicate with.

[francisco]

Nov 26, 2021 6:03:51 GMT -8 Admin said:

Hi Francisco: I never had experience with that brand (Kinco), but we see a common problem within your question, that my insight may help. Or may not, but here it is anyway.

With AB/Rockwell PLCs, they made serial connection supper easy. 1 click of a button and their communication software (RSLinx) tries every possible setting for RS232 communication until it successfully establishes communication and sets everything up for you.

Yet even that brand is the easiest to work with out of all brands when a new user to using a USB to RS232 converter, gets stuck with failure to communicate. What they overlook, is each time you plug in a converter cable to your USB, your computer picks a random port number not already being used on your computer. The user of the AB PLC/RSLinx communication software has to look up what comm port number the computer/USB to RS232 software picked for the converter. Then they have to open the RSLinx PLC communication software and change the port number of the RS232 driver within, to match the port number used by USB/RS232 converter software. Then RSLink can automatically detect all the rest of the communication settings (IE: baud rate, parity, etc., etc.). So you may want to check if a similar problem is occurring with your setup.

So check:

* Comm port number in communication software is the same as comm port number in USB/RS232 converter.
* Check that all RS232 settings in the Software are the same as set in the PLC you are wanting to communicate with.

Hi Admin,

Thanks for your response. I checked the programming software and it has a similar way to establish the connection.

I could establish a communication through a so called free-protocol that the software provides. Now I'm dealing with MODBUS protocol, however, I've made some progress.

Thank you for your attention. Kind regards.