Note

Basic sensors communication concepts are described on the corresponding page

Pfeiffer pressure gauges

Pfeiffer manufactures a range of pressure gauges and controllers with several different standards and communication protocols. The code has been tested with Pfeiffer TPG260 series controller (specifically, TPG261) and Pfeiffer DPG202 controller.

The main device classes are pylablib.devices.Pfeiffer.TPG260 and pylablib.devices.Pfeiffer.DPG202.

Software requirements

The devices provide a bare RS232 interface, so any appropriate USB-to-RS232 adapter should work.

Connection

Since the devices are identified as COM ports, they use the standard connection method, and all you need to know is their COM-port address (e.g., COM5):

>> from pylablib.devices import Pfeiffer
>> gauge = Pfeiffer.TPG260("COM5")
>> gauge.close()

Operation

TPG260 series

The operation of this gauge is fairly straightforward, but there is a couple of points to keep in mind:

  • On measurement error TPG260.get_pressure() returns None. To get the underlying issue, you can use TPG260.get_channel_status()
  • By default, the pressure is always returned in Pa regardless of the display units. This behavior can be overridden by setting display_units=True in TPG260.get_pressure().
  • In case an error occurs, you can use TPG260.get_current_errors() to get the list of currently active errors and TPG260.reset_error() to reset them.
  • This communication protocol for 350-series gauges (361, 362 and 366) is similar, so the device class should also be able to work with them. However, it has not been tested.

DPG202/TPG202 controller

There is a variety of different controllers which implement a similar protocol: DPG202 and TPG202, as well as a variety of RS485-controlled gauges (e.g., CPT200). It is based on requesting parameters with certain 3-digit numbers. These are fairly consistent between the devices, for example, 312 stands for the software version, 740 for pressure, and 349 for the device name. However, different devices implement different subsets of these parameters. The supplied class provides a generic interface through DPG202.get_value() and DPG202.comm() methods, which, correspondingly, request or set a value of a given parameter given its number (e.g., 740) and datatype (e.g., "string", "u_expo_new", or "u_short_int"). Both of these pieces of information are usually provided in the controller or gauge manual in the Parameter overview (or similar-named) section. Currently the device class provides only the most basic functionality:

>> from pylablib.devices import Pfeiffer
>> gauge = Pfeiffer.DPG202("COM5")
>> gauge.get_pressure()  # pressure in Pa
9.78E4
>> gauge.get_value(740,"u_expo_new")  # request the parameter directly, yields pressure in mBar
9.78E2
>> gauge.close()