Brooks Instrument 5851EM - Manual (Page 8)

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Brooks ® Models 5965, 5851EM
Section 1 Introduction Installation and Operation Manual
X-TMF-5965-5851EM-MFC-eng
Part Number: 541B122AAG
September, 2009
• Fast response control permits rapid gas settling times with minimal
over/undershoot.
• Soft start provides a flow ramping function which slows down the
introduction of process gas for those processes which cannot tolerate
rapid flow transition. Refer to section 2-7 and Figure 1-1.
• Valve override permits the user to fully open and close the control
valve independent of the command setting. Refer to Section 2-6.
Figure 1-1 0 to 100% Command Step, Soft Start Enabled
• Low command flow cutoff (Auto shut-off) prevents the valve from
opening whenever the setpoint is less than 2% of full scale.
• Output limiting prevents possible damage to delicate data aquisition
devices by limiting the output signal of the mass flow controller.
• Valve off (Note 1) is accessed via Terminal J on the card Edge or Pin 4
on the D-Connector version. This feature allows the user to close,
independent of the command signal, the control valve by supplying TTL
level low signal to the proper terminal. This function is useful when
performing repetitive flow operations or as a safety shutdown. Refer to
section 2-6.
• Valve test point/purge (Note 1) is accessed via Terminal D on the
Card Edge or Pin 7 on the D-Connector version. This feature allows the
user to monitor the control valve voltage during operation. Also, ground-
ing this terminal causes the control valve to fully open independently of
the command signal. Refer to Section 2-6. Note: Grounding this
terminal with a Model 5965/5851EM supplied with a normally open
valve will cause the valve to fully close.