Passthrough Mode; Data Format - SATO CL4NX Programming Reference Manual

10.3 Passthrough mode

This mode works when printer's power is turned on. It communicates with printer via NFC tag.
Data is communicated between NFC device and NFC tag, and is uncompressed by NFC controller to send (pass through)
data directly to the printer.
Purpose: For sending small amounts of SBPL data (to print), printer setup, collecting values and status.
The "small amount of data" here means around 1000 bytes (on assumption to scan the device within 2 seconds with speed of
8Kbps as a measured value.) It is recommended to use handover mode if data is larger than this size.
Note: Make sure to check the buffer status in the RS parameter of DC2+PG command to control the transmission (make sure
not to send print data until buffer near full is cleared) if printer near full (2MB or more on printer's receive buffer) is going to
happen in the operation, since this does not allow two-way communication

10.3.1 Data format

Transmission data format
(1) (2)
Number of data
Transmission data after compression
in bytes
(4 bytes)
(1)
Number of bytes for transmission
Sets the number of transmitted bytes in big endian.
(2)
Transmission data after compression
Sets transmission data after zlip compression.
The maximum size before compression is 51200 bytes.
(3)CRC
Sets CRC of the transmitted data before compression. CRC-16-CCITT is used for CRC.
See Chapter 10.3.3 for details.
SBPL
command
Status and equipment
information
.
NFC controller
buffer : 50KB
(3)
CRC
2 bytes