946 Controller Instruction Manual
pg. 48
The flow set point should be set via the MFC Channel Setup screen as described in
section 6.7.2. Due to the limited space, only 3 digit resolution is displayed (for example, a
set point of 1350 sccm will be displayed as 1.35E+3).
6.7.2 Setup MFC Controlling Parameters for Flow Control
When an MFC is connected to the 946 controller, parameters must be entered and set in order to ensure
the proper operation.
The Mass Flow Controller setup screen can be accessed by moving the green LED indicator to the
desired MFC channel first, then press the
Channel
Setup
button on the 946 front panel. See Figure 6-13.
Setup MFC (sccm) C1
Scale Factor
FD
Relay
Relay 02
Relay 01
Enable
Dir/Ch
SET SP
ABOVE
Hyst
ON
3.00E+1
2.70E+1
BELOW
OFF
8.00E+2
8.80E+2
Zero
NO
FlowRate SP
2.00E+2
1.0E+3
Nominal Range
1.40
OP Mode
Setpoint
NO
Range
1.40E+3
Operation Voltage:
+15 to 24v
Figure 6-13 MFC Setup Information Display
1. Scale Factor
Scale Factor is the gas correction factor ratio between the operating gas and the factory
calibration gas. If the factory calibration gas is nitrogen, the Scale Factor is identical to
the gas correction factor. Typical gas correction factor values are listed in Chapter 13.
Move the cursor to the Scale Factor box, press
Enter
key to highlight the parameter (dark
gray background), use the
and
keys to select desired value, and press
Enter
key
again to save the value. The valid range is 0.1 to 10, with a default setting of 1.00.
2. Nominal Range
Nominal Range is the flow range in SCCM specified on the MFC with its factory
calibration gas. To set the Nominal Range, move the cursor to the Nominal Range box,
press
Enter
key to highlight the text, use the
and
keys to select the full scale flow
rate for the MFC, and then press
Enter
key again to save the value. Note that flow
parameters on the 946 set up screen are always in units of SCCM with a valid range of