CognitiveTPG B780 - Manual (Page 108)

Chapter 5: Programming commands 96
A776 (B780) Programming Guide A776-PG00001 C 12/09
Unsolicited status mode
Select or cancel unsolicited status mode (USM)
ASCII: GS a n
Hexadecimal: 1D 61 n
Decimal: 29 97 n
Value of n: 0 turns mode off;
any non-zero value turns mode on
Default: 0 (USM disabled)
Enables or disables automatic return of 4 status bytes whenever one or more of the listed changes occurs. This
command is a batch mode command; that is, it is processed after all prior data in the input buffer has been processed.
There may be a time lag between the printer receiving this command and enabling unsolicited status mode (USM),
depending on the pending input buffer contents.
If an immediate return of printer status is desired, then any of the other status commands should be issued following
this command. Once this mode is activated, the printer automatically transmits 4 status bytes whenever any of
the conditions change. If an RS-232C connection with hardware flow control is used, all four status bytes will be
transmitted without checking DSR.
This command is a POS version of general printer unsolicited status functions; it uses the same command code as older
versions of the POS command “automatic status back (ASB)” but has the following differences:
• The parameter n is an on/off switch; it does not select trigger subset.
• There is no immediate return when this mode is turned on.
• All 4 status bytes are always returned.
A change in any of the following conditions will trigger the USM response:
• Cash Drawer
• Receipt Cover
• Knife Error
• Out-of-Range Printhead Temperature
• Out-of-Range Voltage
• Paper Exhaust Status
• Slip Paper
Related information
When Unsolicited Status Mode is enabled using this command, the status transmitted by other commands and the
USM status are differentiated according to the information found in Recognizing Data from the printer, which follows
the USM return description.
The status bytes to be transmitted are described in the following four tables.
Byte 1 = printer information
Byte 2 = error information
Byte 3 = paper sensor information
Byte 4 = paper sensor information