The Negotiation Phase
225
Byte Mode
The printer and host send data to each other along eight data lines (one bit
per line).
If bidirectional communication is supported by the printer and the host, the
host will take control of the data transfer.
The Negotiation Phase
The negotiation phase determines which operating mode will be used. At this
time, the host and the printer will sense what devices are attached, the
supported signals available, and which mode to use. The selected mode, in
turn, defines the pins on the 1284 connector.
There are 36 pins on the parallel interface. Each one sends a different signal.
Pin 1, for example, can send a Strobe signal or a HostC1k signal, depending
on the mode selected. See Table 8 for the different connector signals.
Signals
Table 8 lists each of the signals associated with the corresponding pins on the
1284 interface. Descriptions of the signals follow.
Table 8. 1284 Signals
Pin
Source of Data
Type of Mode
Compatible
Nibble
Byte
1
Host
nStrobe
HostClk
Host/Clk
2
Host/Printer
Data 1 (LSB)
3
Host/Printer
Data 2
4
Host/Printer
Data 3
5
Host/Printer
Data 4
6
Host/Printer
Data 5
7
Host/Printer
Data 6
8
Host/Printer
Data 7
9
Host/Printer
Data 8 (MSB)
10
Printer
nAck
PtrClk
PtrClk
11
Printer
Busy
PtrBusy
PtrBusy
12
Printer
PError
AckDataReq
AckDataReq
13
Printer
Select
Xflag
Xflag
Содержание 6500 Series
Страница 2: ......
Страница 6: ......
Страница 24: ...24 Chapter 1 Taking Care of Your Printer ...
Страница 56: ...56 Chapter 3 Changing the Power on Configuration ...
Страница 214: ...214 Chapter 4 Printer Information Menu ...
Страница 230: ...230 Chapter 5 IEEE 1284 Parallel Interface ...
Страница 304: ...304 Appendix B Printing Speed ...
Страница 310: ...310 Appendix C Compatibility and Limitations ...
Страница 334: ...334 Communication Statements ...
Страница 358: ...358 ...
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Страница 360: ...Printed in U S A S550 1335 03 07S550133503 ...