MKS 651C, Instruction Manual, Page: 65 / 172

Chapter Five: Local Operation How To Activate Set Points
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How To Activate Set Points
Activating a set point causes the 651 unit to control to that set point. To activate a set point,
press the appropriate set point key (A through E).
The system responds by illuminating a light in the set point key and controlling according to the
selected set point. The front panel display changes to reflect the activated set point. That is, the
display at the top shows the actual pressure and the display at the bottom shows the valve
position.
The light remains lit in the set point key until another set point (or valve function), is chosen.
How To Identify an Out-of-Range Condition
An out-of-range condition occurs at ±105% of F.S. (±10.5 Volts at sensor input) and is displayed
as a positive or negative polarity. An example of a positive out-of-range condition for a set point
is shown below.
SP A 3.000 Torr
PRES +++++++
An example of a negative out-of-range condition displayed on the default screen is shown below.
PRES - - - - - - Torr
POS 0.0 %