Operation
32
GA09420_002_C0 – (2016-10) –
Leybold
Admissible input strings
For commands to the transmitter, six defined strings are used:
Byte
No
Command
0 1 2 3 4
2)
Set the unit mbar in the display
3
16
62
0
78
Set the unit Torr in the display
3
16
62
1
79
Set the unit Pa in the display
3
16
62
2
80
Power-failure-safe storage of current
unit
3 32 62 62 156
Switch degas on
(switches itself off after 3 minutes)
3 16 93
148 1
Switch degas off before 3 minutes
3
16
93
105 214
2)
Only low order byte of sum (high order byte is ignored).
4.7
Profibus Interface (ITR 90 P)
This interface allows operation of ITR 90 P with part number
230030 and
230031
in connection with other devices that are suited for Profibus operation. The physical
interface and interface firmware of ITR 90 P comply with the Profibus standard
(
→
[4], [5]).
Two adjustable switching functions are integrated in the ITR 90 P. The corre-
sponding relay contacts are available at the sensor cable connector (
→
20, 34).
The basic sensor and sensor electronics of all ITR 90 transmitters are identical.
Caution
Caution: data transmission errors
If the transmitter is operated via RS232C interface and Profibus
interface at the same time, data transmission errors may occur.
The transmitter must not be operated via RS232C interface and
Profibus interface at the same time.
4.7.1 Description of the Functions
Via this interface, the following and further data are exchanged in the standardized
Profibus protocol (
→
[3]):
•
Pressure
reading
•
Pressure unit (Torr, mbar, Pa)
•
Degas
function
•
Transmitter
adjustment
•
Status and error messages
•
Status of the switching functions
