INFICON HLD6000 Refrigerant Leak Detector Interface Description - Manual (Page 17)

LD Protocol 17
Cmd H/L: Command: Command-specifier
Command name in plain text
• 7-Bit ASCII, only printable characters (from 0x20 to 0x7E)
• Always in English
• Units in square brackets
DATA Data belonging to
master request (Slave
reply to write command
is sent without data) 0 ≤ n ≤ 248
If I/O module (7-byte additional header) is
used, then limit maximum data length to
241.
CRC Checksum Calculate CRC for all bytes (except CRC
byte)
Polynomial: 0x98,
Name: DOWCRC,
Maxim/Dallas, X
8 +X 5 +X 4 +1
Info:
CRC calculation see document
"CRC_calculation.c" (C souce code)
Bit 15 ... 13 Meaning High Nibble (Hex) Comments
000 Read value 0
001 Write value 2
010 Read lower limit value 4 Min values also
defined for read
commands.
011 Read upper limit value 6 Max values also
defined for read
commands.
100 Read default value 8 Def values also
defined for read
commands.
101 Read command name in
plain text A Please refer to
chapter “Command
name in plain text”
below.
110 Read command info C Please refer to table
“Command info”
below
111 not used E
Command Meaning