Using The Packet Protocol - Kramer VS-1616DN-EM User Manual

Using the Packet Protocol

The packet protocol is designed to transfer large amounts of data, such as files, IR
commands, EDID data, etc.
To use the packet protocol:
1. Send a command, for example LDEDID
2. Receive READY or ERR###
3. If READY:
•
Send a packet
•
Receive OK on the last packet
•
Receive OK for the command
4. Packet structure:
•
Packet ID (1, 2, 3...) (2 bytes in length)
•
Length (data length + 2 for CRC) – (2 bytes in length)
•
Data (data length -2 bytes)
•
CRC - 2 bytes
5. Response:
~NNNNSPOKCR LF
Where NNNN is the received packet ID in ASCII hex digits.
When calculating the CRC, the polynomial for the 16-bit CRC is:
CRC-CCITT: 0x1021 = x
Initial value: 0000
Final XOR Value: 0
For a code example, see:
CRC example:
Data = "123456789"
Result => 0x31C3
VS-1616DN-EM – Protocol 3000
01 02 03 04
Packet ID Length
16 12 5
+ x + x + 1
sanity-free.org/133/crc_16_ccitt_in_csharp.html
05...
Data CRC
Kramer Electronics Ltd.
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