Precautions - Citizen iDP-3221 Series User Manual

2.3

Precautions

1) The Negotiation phase is triggered with the rising edge of the IEEE 1284 Active signal sent by the host.
2) In Compatibility mode, the time when the negotiation process begins is, as a general rule, after the host sets
nStrobe to High and then the printer outputs an nAck pulse.
Once the nStrobe signal is set to High, however, the printer immediately moves into the Negotiation phase
when the high state of IEEE 1284 Active is detected, even if the nAck pulse has yet to be output or is being
output. In this case, if the printer has returned to Compatibility mode after Termination, no nAck pulse will
be output.
3) Negotiations can be entered from the Busy or Error state of the Compatibility mode.
will not return to the Busy or Error state it was in before the negotiations, but will remain in the printer state it
was in after Termination.
4) If the host requested a communication mode that is not supported by the printer, it must move into the
Termination phase and return to the Compatibility mode.
Table 2.4.1
Bit
7
Request Extensibility Link
6
Request EPP Mode
5
Request ECP Mode with RLE
4
Request ECP Mode
3
Reserve
2 Request Device ID: Return Data Using
Nibble Mode Rev Channel Transfer
Byte Mode Rev Channel Transfer
ECP Mode Transfer without RLE
ECP Mode Transfer with RLE
1
Reserve
0
Byte Mode Reverse Channel Transfer
None Nibble Mode Reverse Channel Transfer
Illegal or Contradictory Request
Note: The printer only supports the Nibble and Byte modes. For a request for any other mode, Xflag is set to Low.
Definitions of Request Bits in IEEE 1284 Communication Mode
Definition
Bit Values
(76543210)
10000000
01000000
00110000
00010000
00001000
00000100
00000101
00010100
00110100
00000010
00000001
00000000
Other than
Other than above
131
iDP3221 User's Manual
In this case, the printer
Xflag
Hex.
When
supported
80H High
40H High
30H High
10H High
08H High
04H High
05H High
14H High
High
34H
02H High
01H High
00H Low
above
In the
printer
Low
Low
Low
Low
Low
High
High
Low
Low
Low
Low
Low
Low
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