Samsung SRP-275 Operator's Manual page 57

CHAPTER 5
CONTROL COMMANDS LIST
NV user memory data remains valid until the host sends a deletion or
storage function command.
Data is written to the non-volatile memory by Function 1, 2, or 3.
When using those commands, note the following:
- The printer may be BUSY while the functions are performing.
The printer does not process any received data while it is BUSY;
therefore, under no circumstances should the host send data at this time.
Note the rules below for the operating NV memory (store data / cancel data):
- Paper feeding is disabled by the paper FEED button.
- The printer ignores real-time commands.
- Even if "ASB is enabled" is specified, the printer does not send
ASB status.
You can use the NV user memory as an index of note for the following:
- Customize information: index of the NV bit image definition contents.
- Maintenance information: ink ribbon replacement date, telephone
number of company, etc.
[Notes for transmitting processing of the block data]
- Data is send by Function 2, 3, 4, or 5. When you use these functions, obey the following
rules.
- When the host PC transmits the function data, transmit the next data after receiving
the corresponding data from the printer.
- With serial interface printers, use this function when the host is READY.
- With a parallel interface printer, data sent (excluding ASB status) with this command
("Header to NUL") is temporarily stored in the printer send buffer, as with other data.
When the host goes into Reverse mode, the printer then sends the data sequentially
from the beginning of the send buffer. When using this command, promptly change
into Reverse mode to start the data receive process.
- You cannot use ASB status and real-time commands while "Header to NUL" data is
being sent.
- When communication with the printer uses XON/XOFF control with serial interface,
the XOFF code may interrupt the "Header to NUL" data string.
- The transmission information for each function can be identified to other transmission
data according to specific data of the transmission data block. When the header
transmitted by the printer is [hex = 37H/decimal =55], treat NUL [hex = 00H/decimal =0]
as a data group and identify it according to the combination of the header and the
identifier.
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[Notes for ESC/POS Handshaking Protocol]
Use ESC/POS Handshaking Protocol below for Functions 2 and 5: identifier.
Step Host process
Start processing of Function 2.
1 Send GS ( C <Function 2>.
(Read specified record back to host.)
2 Receive data from printer. Send data in memory.
3 Send response code. (*1) Continue processing (*2) (*3) according to response.
(*1) Response code
ASCII Hex Decimal
ACK 06 6 Send next data.
NAK 15 21 Resend previously sent data.
CAN 18 24 Cancel send process.
(*2) Processing according to response
(unsent data exists, identified by send data set "Identification status")
Response code Process
ACK Start send processing for next data.
NAK Resend previously sent data.
CAN End processing for this command.
Processing the codes except for ACK, NAK, and CAN performs the same processing as CAN.
(*3) Processing according to response
(no unsent data, identified by send data set "Identification status")
Response code Process
ACK, CAN End processing for this command.
NAK Resend previously sent data.
Record data definition area capacity is 64 KB.
Printer process
Request
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