Error Number (Receiving String); Calculation Of The Checksum - LEYBOLD GRAPHIX ONE Instruction Manual

8.2.2.3

Error Number (Receiving String)

Error-No.
-6
-8
-9
-10
-11
-12
-13
-14
-15
-16
Table 69 – Error numbers of receiving string
8.2.2.4

Calculation of the Checksum

The checksum (CRC) consists of an ASCII character, the byte value of which results as
follows from the preceding characters of the send or receive string (without address RS485):
CRC = 255 – [(Byte sum of all preceding characters) mod 256]
If this value is lower than 32 (control character of the ASCII code), then 32 must be added.
Example:
Send string ahead of CRC designating the first channel: [SO]1;5;vacuum[space character]
CRC = 255 – [(14+49+59+53+59+118+97+99+117+117+109+32) mod 256]
= 255 – [923 mod 256]
= 255 – 155
= 100
In this case the checksum character is a "d".
100
CRC sum error
Format error
Group not available
Parameter not available for sensor type
Parameter read-only
Parameter value incorrect
Number of parameter values wrong
Value currently not changeable
Parameter generally not available
Error data handling with USB
Explanation
GA300550402_002_C1 – 10/2016