INFICON SKY CDGxxxD (RS232C) - Manual (Page 3)

tira49e1-a (2010-02) RS232C.cp
3
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
3
2 Constant value for CDG025D 1)
Constant value for CDGxxxD 2)
Constant value for CDG025D 3)
2 Status → "Status byte"
3 Error → "Error byte"
4 Measured value high byte > → "Calculation of pressure value"
5 Measured value low byte > → "Calculation of pressure value"
6 Read command > Read value
7 Sensor type → "Sensor type"
8 Checksum → "Synchronization"
1) CDG025D with output signal 10.00 V (analog)
2) CDG045D, CDG100D, CDG160D, CDG200D with output signal 10.24 V (analog)
3) CDG025D with output signal 10.24 V (analog)
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)
1 Sensor temperature attained 1)
1) for CDG045D, CDG100D, CDG160D, CDG200D only
1.1 Send String
Structure of send string
Status byte
(byte No. 2)