Printer Accessories User Manual

Page 11-3TRANSPARENCY MODES
Pseudo Transparency Mode
The ULTRA has its own form of transparency, called pseudo transparency
mode (PTM). Unlike IBM 35h and Xerox 36h transparency, pseudo
transparency can be used in both DSC and SCS data streams.
This type of transparency has two forms: Trigger 1 + Trigger 2 (or two-
trigger) and Trigger 1 + count byte (or one-trigger). In either trigger
method, the only valid characters following the trigger sequence are the
numerals 0-9 and the letters A-F.
The type of pseudo transparency selected is determined by Option #30 
Pseudo Transparency Mode Selection. The default is (A) Trigger 1 +
Trigger 2. If the user selects (B), Trigger 1 + Count Byte PTM will be used.
Trigger 1 + Trigger 2 PTM
In the two-trigger mode, the user selects the trigger using any two
characters that are not commonly found together in the printable data
stream (see Section 5  Configuration Options and refer to Options 32-35
for information on restrictions on the selection of triggers). The default
trigger characters are a cent sign and a dollar sign (¢$).
In this method, no count byte is required. Rather, all pairs of bytes
following the trigger are combined and printed until terminated with an
invalid character (valid characters are 0-9 and A-F).
Note: The system may insert a NL command (an invalid character) in the
data stream. This will terminate two-trigger pseudo transparency.
In the following examples, the cent sign-dollar sign sequence (¢$) is used as
the trigger. Note that the cent sign (an invalid character) is also used as the
terminator.
To send one ASCII escape character requires five input characters  the
first trigger (¢), the second trigger ($), the hexadecimal ASCII escape
character (1Bh) and an invalid character/terminator (¢):
¢$1B¢
To send the Xerox 4045 reset sequence requires nine characters  the first
trigger (¢), the second trigger ($), the hexadecimal reset sequence (1Bh,
2Bh and 58h) and an invalid character/terminator (¢).
¢$1B2B58¢