Operation; Before Switching On; Configuring The Data Exchange - Pfeiffer PPT 100 Operating Instructions Manual

6 Operation

6.1 Before switching on

6.2 Configuring the data exchange

Parameter overview
Reading the actual
pressure value
[P:740]
After switching on the power supply, the transmitter is ready for operation. However, it is
advisable to wait for a stabilization period of 5-10 minutes before measurement, and to
operate the transmitter without interruption during the measurement process.
The pressure measured in the Pirani range depends on the gas type. To adjust for differ-
ent gases, a corresponding gas type correction factor can be set on the transmitter; this
generates correct measurements in the pressure range below 1 mbar. The gas type cor-
rection factor is factory-set for air and N
Communication is carried out, depending on the address selector switch setting, via the
serial RS-232 interface using the relevant display units or via RS-485 using the Pfeiffer
Vacuum protocol:
● 9600 baud
● 8 data bits
● 1 stop bit
● no parity
# Name
DeGas
40
Sensor on/off
41
Switch mode
49
Actual error code
303
Software version
312
Component name
349
Pressure in [mbar]
740
Pressure set point
741
Correction value
742
(Pirani)
Correction value
743
(Bayard-Alpert)
Correction value
743
(CC sensor)
Parameters are displayed in square brackets as a three-digit number in bold font. The
designation may also be stated if necessary.
Example: [P:312] Software version
Pressure value as the value to be queried and also as equalization (see below) are trans-
mitted by means of a string in the format "aaaabb", whereby "aaaa" is the mantissa and
"bb" the exponent with offset 20 of an exponential number. "aaaa" is therefore in the
range "1000" (for 1.000) to "9999" (for 9.999). The individual characters of the string are
the numbers "0" (ASCII 48) to "9" (ASCII 57).
Example: "104223" represents 1.042 x 10
mbar.
to 1.00 (see p. 18, chap. 10.3).
2
Data type Handling
6 - boolean_new readable, writable
7 - u_short_int readable, writable
7 - u_short_int readable, writable
4 - string read-only
4 - string read-only
4 - string read-only
10 - u_expo_new readable, condition-
ally writable
7 - u_short_int only writable
2 - u_real readable, writable
2 - u_real readable, writable
2 - u_real readable, writable
+3
mbar, "750015" represents 7.500 x 10
Operation
-5
11