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Manually Overriding the Backfill Relay
Relay 2 is used as the backfill valve control relay when it is enabled with the BE1 command (see page 20). It
also can be manually overridden directly with the messages described here.
Note
These messages activate or deactivate relay 2 even if the backfill function is disabled. For
example, if relay 2 is being used to control an alarm, deactivating the relay may disable the
alarm.
To activate relay 2, issue the command:
OB
The controller activates the relay.
To deactivate the relay, issue the command:
CB
The controller deactivates the relay.
To report the activation status of relay 2, enter:
RB
The controller responds:
BF
value
where:
BF0 = deactivated
BF1 = activated
Reporting Applied Analog Input Voltage
To report the applied input voltage for the analog setpoint as a percentage of full scale, send the command:
R 0
If the actual voltage input is 100% of the analog setpoint FS range, an example response is:
S
0 100
Slow Pump Introduction
The Slow Pump feature is implemented to allow a gradual change in chamber pressure when transitioning
from the current pressure to a new setpoint.
The enabled Slow Pump feature will constantly adjust the current setpoint along a control curve until the
desired (final) setpoint is reached. Slow pump functions for decreasing, increasing or both decreasing and
increasing pressure setpoints, depending on the setting of the slow pump enable. The desired setpoint and
slow pump rate is programmable via RS232 or DNET commands. When slow pump is enabled, the final
pressure setpoint is approached at the defined rate (Torr/s). Setpoint entry is done in the same manner whether
slow pump is enabled or disabled.
