INFICON SID-242 Thin Film Deposition Controller - Manual (Page 85)

Chapter 6 Computer Interface
6-4
Update Command:
@<command>;<param1>;...;<paramn>;<data>;<Chksum><CR>
Update Example: Set Process
@UP;11;MyProcess;44<CR>
Description:
@;UP; Update Process command
; Separator
01 Parameter 01 (Set Process)
; Separator
MyProcess Data
; Separator
?? Checksum
<CR> Carriage Return (ASCII 13)
Response Example: Set Process Completed
@UP;<ACQ>;??<CR>
Response Example: Set Process Failed
@UP;<NAK>;<ERR>;??<CR>
(Response to
Update Process)
ERR:
01 Illegal Command
02 Illegal Parameter
03 Illegal Format
04 Checksum Error
05 Request Denied
06 Unknown Error
Checksum Calculation
The sample code below calculates the FCS checksum of a string of characters.
In the code, Message is a string that has been stripped of terminator and
checksum characters before being passed to this routine
' XOR ASCII codes
For i = 1 To Len(Message)
FCS = Asc(Mid$(Message, i, 1)) Xor FCS
Next i
' Convert FCS to two character hex string
If Len(Hex$(FCS)) = 1 Then
CalcChkSum = "0" & Hex$(FCS)
Else