Interface Boards

#8143 New Serial Interface board

If you are using an optional interface, it may be necessary for you to alter the communications protocol of the printer or the computer so that they can communicate properly. In most cases, you should use the information in your optional interface manual or your computer’s manual to match the computer with the interface.

If you are using the #8143 optional interface board with the printer, make sure that you read through the sections below on baud rate selection and handshaking timing.

For all other data transfer conventions, such as word structure or communications protocol, use the information in the manual supplied with your #8143 optional interface.

Baud rate selection

You can select baud rates from 75 to 9600 BPS (Bits Per Second). When setting the baud rate, make sure you use the bit rate selection table for printers with buffers (in the #8143 interface manual).

Handshaking timing

When the vacant area for data in the input buffer drops to 256 bytes, the printer outputs an X-OFF code or sets the DTR flag to "1" (MARK) indicating -that it cannot receive data.

Once the vacant area for data in the buffer recovers to 528 bytes, the printer outputs an X-ON code or sets the DTR flag to “0” (SPACE) indicating that it is ready to receive data.

5-52 Using the Printer Options