Echo –8, Write device control memory –8 – Unisys E-@CTION EFP9800 User Manual

Page 196

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NCR 5021 Printer Emulation Commands

8–8

3255

4073–002

Echo

When the printer receives this command, it takes the data following 1B 5B 7A vv
yy, converts the data to unpacked ASCII, and returns the converted data to the
host computer. This is useful when performing diagnostics on the printer.

This command is executed immediately, regardless of the state of the printer.

Hexadecimal Decimal

ASCII

1B 5B 7A vv yy yy...yy

27 91 122 vv yy yy…yy

ESC ] z vv yy yy…yy

Value of vv Value

of

yy

0-80H 0-FFH

The printer sends the following in reply to the message: 1BH, 5BH, vvH, vvH,
yy

H, ... yyH, 70H.

The value of vv is the number of bytes sent (in unpacked ASCII).

The value of yyyy...yy is the data sent in the ECHO message (in unpacked
ASCII).

Write Device Control Memory

This command modifies the character set loaded in memory. Each character in
the character set consists of seven 12-bit dot patterns.

Data that is forced outside the range of the character set by an incorrect
address is ignored. There are 224 characters in the character set and each
character consists of seven 12-bit patterns.

This command is processed only when the printer is offline.

The 5021 J/V printer’s character field is 9 dots wide and 7 dots high (9x7). When
SPI 5021 prints a line, it automatically inserts space between characters
equivalent to three dot positions which are inaccessible to the user. Countries
that use the Arabic language require that this area be accessible. As a result, the
5021 RS-232C J/V printer implements a 12x7 character field and does not insert
space between characters.

There are 224 characters in the printer’s character set. The range of hex values
for the characters is 20-FF. Hexadecimal values in the range of 00-1F that are
not control characters are printed as ASCII spaces (20).

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