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A-Series COM Port Notes

COM1 and COM2 (external) serial ports

The COM1 and COM2 (external) serial ports on the 15A1, 15A2 and 17A2 touchcomputers use RJ45 connectors.

On these RJ45 connectors the following signal lines are not available:

  • Data Carrier Detect (DCD)
  • Data Set Ready (DSR)
  • Data Terminal Ready (DTR)

If your POS software/driver/device requires one of these lines, you may encounter problems (error messages, non working devices etc.).

It may be possible to disable hardware handshaking for the POS software/driver so that it will ignore the missing lines. On the Epson TM-88 printer, set switch 3 on switchpak 1 to the ON position. The switchpak is accessible through a sliding access panel on the bottom of the printer. For some peripheral devices, the only viable solution might be to use a USB-Serial adaptor. Select one that uses all the signal lines.

We recommend the Keyspan USA-19HS USB to Serial adapter; see www.tripplite.com.

Note: If the serial COM port on the 15A2 is not functioning properly, the system BIOS may need an update; the BIOS update changes low level RS-232 operation to be backwards compatible to legacy 16 bit applications only. Please contact Tech Support for assistance.

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