MKS 937B - Page 22

MKS 937B Operation Manual
22
 The control status of ion gauges
 The auto zero channel for pirani/CP/CM sensors
 Leak checking status (activated by the leak check button)
 System self-checking information (board status, sensor status, pressure range, and etc)
 Front panel locking status (when REMOTE is displayed, the front panel is locked remotely)
Controller operation is very simple. For example, to access the system setup screen, simply push the
System Setup button. This permits single-screen access and adjustment for all of the control and
display parameters for each sensor connected to the controller. An LED indicates the current active
channel and all of the parameters associated with the sensors are displayed by pushing the Channel
Setup button.
In addition to the pressure values displayed on the screen, three types of analog signals are also
shown:
 Buffered analog outputs for each sensor (up to 6). These buffered analog signals respond
immediately to sensor signal changes, therefore, can be used in critical fast control
applications.
 Logarithmic/linear analog outputs for each pressure sensor (up to 6) ranging from 0 to 10 V.
The scale for these analog outputs can be adjusted as desired. While these linear signals are
somewhat simpler to deal with than the sensor-dependent buffered analog signals, there is a
longer time delay (<100 msec) due to the signal processing required by the microprocessor.
 There are also combined analog outputs (up to 2) available. By combining the sensors with
different measurement ranges (such as Pirani and cold cathode sensors), analog signals with
much wider range are available. This eliminates the requirement for switching/selecting the
sensor. The time delay for these analog outputs is around 100 msec.
Twelve (12) mechanical relays with independently adjustable controller relay set points allow the
937B to control the operation of critical components in a vacuum system such as valve or a pump.
The set point parameters are nonvolatile, remaining unchanged after powering down or during a
power failure. They may be set or disabled from either the front panel or the optional communications
module.
The Controller also has control set points to turn off ion gauges at higher pressures, extending the
operating lifetime before maintenance is required (for both cold cathode or hot cathode).
Direct computer communication is available to control front panel functions or read pressure and
other information remotely. A RS232/485 serial port is available and the communication protocol can
be selected from the System Setup panel.