INFICON SKY CDGxxxD (RS232C) - Manual (Page 7)

tira49e1-a (2010-02) RS232C.cp
7
Description Data Comment
Read command 0x00 Read command for variable according to
address in byte No. 2
Write command 0x10 Write command for variable according to
address in byte No. 2
Special services 0x40 Direct command (write command) without
data information, e.g. Reset, Zero adjust
Enter the address of the variable to be read/written ( → table "Variables for bytes
No. 2 and 3").
When a variable is written (receipt string) the content of byte No. 3 is written to the
variable addressed in byte No. 2 (
→ table "Variables for bytes No. 2 and 3").
When a variable is read (send string), the value of the variable addressed in byte
No. 2 is output in byte No. 6 of the send string. The content of byte No. 3 is not
relevant for read operations.
The checksum is calculated from the sum of byte No. 1 to 3.
Das Beispiel basiert auf dem Empfangsstring:
Byte No. 0 1 2 3 4
Value 3 0 2 0 2
The instrument or controller (receiver) interprets this string as follows:
Byte No. Designation Value Comment
0 Data string
length
3 (constant value)
1 Service
command
0 Read command
2 Address byte 2 Filter
3 Data byte 0
4 Checksum 2 0 + 2 + 0 = 2
dec ≙ 00 02
hex
High bytes are ignored ⇒
Checksum = 02
hex ≙ 2
dec
Service command
(byte No. 1)
Address byte
(byte No. 2)
Data byte
(byte No. 3)
Checksum
(byte No. 4)
Example