INFICON SID-142 Thin Film Deposition Controller - Manual (Page 68)

Chapter 6 Computer Interface
6-3
Update Command:
@;;...;;;
Update Example: Set Process
@UP;11;MyProcess;44
Description:
@;UP;
Update Process command
; Separator
01 Parameter 01 (Set Process)
; Separator
MyProcess Data
; Separator
?? Checksum
Carriage Return (ASCII 13)
Response Example: Set Process Completed
@UP;;??
Response Example: Set Process Failed
@UP;;;?? (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$(FCS)
Else
CalcChkSum = Hex$(FCS)