Epson TM-L90 Developer's Manual page 95
Hide thumbs
Also See for TM-L90:
- Technical reference manual (212 pages) ,
- Service manual (148 pages) ,
- User manual (112 pages)
Table of Contents
Advertisement
Confidential
Status transfer from printer
In the bidirectional parallel interface, status signals can be transferred from the printer using the
bidirectional function of the IEEE1284 Nibble/Byte modes.
Note:
In this case, different from in the RS-232 serial interface specifications, the real-time interruptions from
the printer to the host are disabled and thus precautions must be taken for the following;
•
The allowable capacity of the printer internal buffer is 99 bytes (except ASB status). The status
signals exceeding this capacity will be discarded. To prevent possible loss of status, the host shall be
ready for data accept data (Reverse Mode).
•
When ASB is used, the host is preferably in the wait state for accepting data (Reverse Idle Mode).
When this state is not available, the host shall enter the Reverse Mode to always monitor the presence
of data.
•
When ASB is used in the Reverse Mode, preference shall be given to the ASB status for transmission
over the other status signals. Any accumulated ASB status signals left for transmission from the last
to the newest ASB status transmission shall be transmitted together at a time as one ASB status,
showing the presence of change, followed by the latest ASB status.
J Example:
Normal ASB status (standby) are shown below.
Status 1
0001 0000
The following data is accumulated when near end detection, R cover open and R cover closed
occur in stated order.
Status 1
0001 0000
Œ
0011 1000
0001 0000
Ž
If an ASB status is received after this, the combined ASBs (Œ++Ž) and the latest ASB (Ž), a
total of 8 bytes is transferred.
Status 1
0011 1000
0001 0000
A-10 Interface And Connectors
Status 2
Status 3
0000 0000
0000 0000
Status 2
Status 3
0000 0000
0000 0011
0000 0000
0000 0011
0000 0000
0000 0011
Status 2
Status 3
0000 0000
0000 0011
0000 0000
0000 0011
Status 4
0000 1111
Status 4
0000 1111
Near end detection
0000 1111
Cover open
0000 1111
Cover closed
Status 4
ASB (Œ++Ž)
0000 1111
0000 1111
Latest ASB
Rev. A
Advertisement
Table of Contents
