If you buy the computer, connecting communication cable by using port which RS-232 ports are equipped basically is general.
Accuracy of communication is hard to expect when RS-232 port cable is over 15m. In this case, you must do RS-422 or RS-485 communication.
In case of doing RS-422 or RS-485 communication, you must use dedicated communication card or CONVERT.
The next is figure of cable access method, when do SERIAL communication.
| RS-232 9 pin-25 pin communication cable connection method |
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| RS-232 9 pin-9 pin communication cable connection method |
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| RS-232 25 pin-25 pin communication cable connection method |
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