DATA ENTRY

This section gives a brief description of serial data communication conditions and handshaking protocols supported by the C82307* /C82308* interface card.

Serial data communications

The C82307* /C82308* interface allows you to select either RS-232D, RS-422A, or 20-mA Current-Loop signal levels for data communication.

This interface card also provides for either DTR (Data Terminal Ready) or X-on/X-off handshaking protocol.

About data entry

To accommodate data entry, the C82307* /C82308* interface card is equipped with a buffer that temporarily stores data before transferring it to the printer. When this buffer becomes full, any additional transmitted data cannot be accepted and is discarded. To prevent such data loss, special handshaking protocols are provided to regulate the flow of data transmission. The two protocols available on the C82307* /C82308* interface card are DTR and X-on/X-off.

To enable data entry to the buffer while RS-232D is selected, DSR and DCD must be held at the positive EIA RS-232D level (SPACE) or DIP switch 3-5 must be OFF. When DIP switch 3-5 is ON and either DSR or DCD is set to the negative EIA RS-232D level (MARK), all received data will be ignored by the interface card.

Note

When a parity error occurs (if parity check is enabled), framing or overrun errors are detected in the data received, and data is either ignored or an asterisk( * ) is printed instead.

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