LEYBOLD IONIVAC Series - Page 30

Operation
30
GA09420_002_C0 – (2016-10) –
 Leybold
Synchronization
Synchronization of the master is achieved by testing three bytes:
Byte No Function Value Comment
0 Length of data string 7 Set value
1 Page number 5 (For ITR 90)
8 Check sum of bytes No 1 … 7 0 … 255 Low byte of check
sum
1)
1)
High order bytes are ignored in the check sum.
Status byte
Bit 1 Bit 0 Definition
0 0 Emission off
0 1
Emission 25 μA
1 0 Emission 5 mA
1 1 Degas
Bit 2 Definition
0 1000 mbar adjustment off
1 1000 mbar adjustment on
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 7 Bit 6 Definition
x x Not used
Error byte
Bit 3 Bit 2 Bit 1 Bit 0 Definition
x x x x Not used
Bit 7 Bit 6 Bit 5 Bit 4 Definition
0 1 0 1 Pirani adjusted poorly
1 0 0 0 BA error
1 0 0 1 Pirani error
Software version
The software version of the transmitter can be calculated from the value of byte 6
of the transmitted string according to the following rule:
Version No = Value
Byte 6
/ 20
(Example: According to the above formula, Value
Byte 6
of 32 means software ver-
sion 1.6)