Star Micronics SP2000 Benutzerhandbuch

51

Auto status is a function that automatically relays any changes that occur in
the status of the printer from the printer to the host.  It is composed of the
“Header -1,” “Header - 2” and “a plurality of bytes of printer states.”
The host always identifies the data using the method of identification for each
byte received.  (For example: This is necessary in consideration of the
receiving side because there is the possibility that the X on/X off code could
be included in the automatic status part way through transmission when in the
Xon/Xoff mode [Serial I/F]).
Conditions for the validity and invalidity of the autmatic status abide by the
initial values of the settings of DIP switch 1-6.  You can change the condition
using the <ESC> <RS> “a” n command after turning ON the power.
You can acquire the automatic status regardless of it being valid or invalid
using the <ESC> <ACK> <SOH> command.

Header 1
Header 1 is 1 byte of information heading the automatic status.  Header 1 is
composed of the items in Table 3-1 below.  Header 1 indicates the byte count
of the transmission of the entire status including Header 1 with bits 1 to 3 and
bit 5.  The host gets the information of the transmitted byte count and always
receives the status data of the amount of the transmitted byte count.  For
reference, Table 3-2 shows the relationship of the actual transmitted byte
count and the Header 1.
Bit 0 is always 1 (always 0 after the second byte) to indicate that it is the
header data of Header 1 so when detecting Header 1, you can check that bit
0 = 1 and bit 4 = 0.
Bit 6 is for future expansion, so it is ignored in the processing on the host.