However, if you wish to disable the port or change these parameters later you can do this in the system BIOS setup. The table overleaf shows the default settings for the panel PC’s serial ports.
COM1 and COM2 are one set. You can exchange the address range and interrupt IRQ of COM1 for the address range and interrupt IRQ of COM2. After exchanging, COM1's address range is 2F8 ~ 2FF and its request IRQ is IRQ3: and COM2's address range is 3F8 ~ 3FF and its interrupt IRQ is IRQ4.
COM3 and COM4 are another set. Their selectable function is the same as the COM1/COM2 set.
Table
Port | Address Range | Interrupt | |
COM1 | 3F8 | ~ 3FF | IRQ4 |
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COM2 | 2F8 | ~ 2FF | IRQ3 |
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COM3 | 3E8 | ~ 3EF | IRQ10 |
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COM4 | 2E8 | ~ 2EF | IRQ5 |
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3.3.2 COM1 / COM2 pin 9 output type setting (JP9)
Table
*Normal operation | +5 V output |
| +12 V output | ||
6 | 5 | 6 | 5 | 6 | 5 |
4 | 3 | 4 | 3 | 4 | 3 |
2 | 1 | 2 | 1 | 2 | 1 |
* default setting
Note: | Pins 1, 3 and 5 are for COM1. |
| Pins 2, 4 and 6 are for COM2. |
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