946 Controller Instruction Manual
pg. 92
Set Combination Channel Parameter
Combo #1
Combo #2
High Middle
Low
C2
B1
A1
NA
NA
NA
Enable
Disable
Enable
Figure 8-8 Setup Screen for Setting Combination Channel Parameters
Once the combination sensors are selected, enable the combined analog output. If invalid channels are
selected, the Enable indicator will stay in the Disabled mode.
The following rules may be used to simplify the combination configuration.
•
The combination must include at least two pressure sensors.
•
NA is when no sensor is assigned
•
If either a Cold Cathode or Hot Cathode is included in the combination, it must be assigned as the
low-pressure range sensor (“Low” in Figure 8.8).
•
If a Pirani or Convection Pirani sensor is included in the combination, it must be assigned as the
middle pressure range sensor (“Middle” in Figure 8.8).
•
When a Pirani or Convection Pirani is used in combination, only HC/CC can be assigned to the
low-pressure range sensor.
•
Only capacitance manometer can be assigned as the high-pressure range sensor.
•
If two or more capacitance manometers are used in a combination, the full scale (f.s) of the high
range CM must be greater than or equal to the f.s. of the middle range CM, which in turn must
have a f.s. greater or equal to the f.s. of the CM used for low range.
•
When multiple capacitance manometers with same full-scale ranges are set in combination, the
output is the average of the outputs from the CMs in combination.
•
Only logarithmic analog output is available for combined analog output.
Combination pressure settings can also be accomplished using following serial commands:
•
Query the pressure
@
254PC1?;FF
for corresponding pressure of combined Aout 1 and @
254PC2?;FF
for the pressure
of combined Aout 2.
•
Set the sensor combination
@
254SPC1!HH,MM,LL;FF
and @
254SPC2!HH,MM,LL;FF
.
Here,
HH, MM
and
LL
are the
channels
(A1, A2, B1, B2, C1, C2, NA)
corresponding to the sensor assigned to High, Middle, and Low range
segments.