1 interface protocol, 1 send string – INFICON Cube CDGsci (RS232C) User Manual
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tira90e1 (2014-01) RS232C.cp
1 Interface
Protocol
The complete send string (frame) is nine bytes (byte 0 … 8) long. Bytes 1 … 7 form
the data string.
Byte No.
Function
Value
Comment
0
Data string length
7
Constant value
1
Page No.
4
Constant value for CDGsci
1)
2 Status
→ "Status byte"
3 Error
→ "Error byte"
4
Measured value high byte
<value
>
→ "Calculation of pressure value"
5
Measured value mid byte
<value
>
→ "Calculation of pressure value"
6 Read
command
<value
>
Read
value
7
Measured value low byte
1)
<value
>
→ "Calculation of pressure value"
8 Checksum
→ "Synchronization"
1)
The "Sensor Type" that is accessible via Byte 7 in all other CDGs can now be deduced
from address 56 (Exponent) and 57 (Mantissa).
Bit 0
Definition
0
Continuous output of measured value
1
Individual measured value (polling)
1)
1)
→ 8, "DataTxMode". Send a read command of any parameter to the gauge for
requesting a send string.
Bit 2
Bit 1
Definition
1
0
Manual setpoint setting
1
1
Zero adjust active
Bit 3
Definition
0
⇔ 1
Toggle bit, changes with every string
received correctly
Bit 5
Bit 4
Definition
0
0
Current pressure unit mbar
0
1
Current pressure unit Torr
1
0
Current pressure unit Pa
Bit 6
Definition
0
Standard measurement mode
1
Reserved for internal use
Bit 7
Definition
0
Heating
1
Sensor temperature attained
1.1 Send String
Structure of send string
Status byte
(byte No. 2)