Hitachi PXR-D, Instruction Manual

Page: 226 / 319

● Communication Timing 6-43
(a) When the IJ printer is off-line
¡
The NAK code is transmitted in response to an ENQ code reception from
the outside.
(b) When the IJ printer is on-line
1 When transmitting printing only
¡ Transmission data is received from the external device. When the
received data is not in error, the ACK code is transmitted and the "not
ready for reception" state prevails.
¡
To switch from the "not ready for reception" state to the "ready for
reception" state, perform one of the following procedures.
1) Perform a printing operation once.
2) Transmit the DC2 (retransmission) code to the IJ printer.
3) Press the Comm On/Off key to enter the off-line mode, and
then switch back to the on-line mode.
¡
If the data transmitted from the external device is in error, the NAK
code is transmitted after receipt of the ETX code.
Since the "ready for reception" state is maintained in this instance,
retransmit the data beginning with the ENQ code.
2 When transmitting print conditions, user pattern characters,
and print data recall
¡
When the data received from the external device is not in error, the
ACK code is transmitted. In this instance, the "ready for reception"
state is maintained.
3 When transmitting printing, print conditions, user pattern
characters, and print data recall
¡
When transmitting printing, print conditions, user pattern
characters, and print data recall, ensure that the print conditions,
user pattern characters, and print data recall are transmitted prior
to the printing. If the printing is transmitted earlier than the other
data, the "not ready for reception" state prevails.
Therefore, the subsequent transmission of the print conditions,
user registration characters, and print data recall causes a
communication error.
6.5 Communication Timing
6.5.1 Signal Timing
6.5.1-1 In overwrite-protected mode
ENQ ENQ
NAK
ETX
STX
ACK ACK
ENQ ETX
STX
ENQ ETX
STX
ENQ
ACK ACK ACK ACK NAK
External
device
IJ printer
Print start signal
Readiness
for reception
(No signal output)
Not ready for
reception
Ready for
reception
Printing
operation
A B C
C
On-line Off-line
(a) (b) (c) (d)
A B
C