Saia-Burgess
Controls Ltd.
Manual PCD7.D23x│Document 26/795; Edition E7│15.04.2005
Software
Free Terminal Protocol Mode
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Free Terminal Protocol Mode compatibilty aspect
The Free Terminal Protocol Mode is compatible with the command set of the SBC
PCD7.D79x series, the so called protocol free terminals series, with some exceptions:
●
Another key assembly is used with adjusted code setting
●
The <ESC>Dkkmm<EOT> key buffering modification command of the
PCD7.D79x is parsed but ignored.
●
The <ESC>Pbbpp<EOT> communication parameters modification command of
the PCD7.D79x is parsed but ignored.
●
At the <ESC>T<EOT> poll command a protective turn around delay is used
which makes it useable on all driving equipment.
●
A RS422 / RS485 multidrop mode is supported for parallel display on passive
and active terminals (usually using address 0 setting, but essentially free to
chose).
●
Point to point is also on RS232 possible, even with RTS half duplex RTS trans-
mission control if wanted.
●
A large extension of the command set using shared PCD7.D23x direct mode
commands can be used. This includes background menu screen use, enlarged
cursor visualization control, and the use of different code maps for alternative
language and standard DOS graphical symbol display.
The PCD7.D23x has been designed for serial line handshake use and must be driven
with proper timing in the non-handshake free terminal protocol mode.
Free Terminal Protocol Mode key polling handler
The key handler is compatible to the PCD7.D23x with the same events detected and
forwarded.
As long as the terminal is active, all key events are stored in a buffer.
They are never sent on the terminal’s initiative.
The values are returned on a poll request only, on a first in first out base.
The used command is
D23x Command
Active on request mode
Description
Details
0x1b 0x54 0x04
<ESC>T<EOT>
Poll the buffer of the
actual active terminal
(if any is connected
and set to active)
This returns the 4 digit ASCII
code ‘xxyy‘.
‘xx‘: Number of queued /
stored key codes incl. the
requested (‘00‘...‘15‘)
‘yy‘: Modified key code (hex)
The terminal returns the the answer with a delay that can be reconfigured with ad-
