Programming and Operation
3-48
P/N 8040406
C
HELIX TECHNOLOGY CORPORATION
-
TI
CRYOGENICS
Rough Valve Open/Closed
CAUTION
Opening the rough valve when the On-Board Cryopump is turned ON
may cause oil from the roughing pump to backstream into the vacuum
chamber and contaminate the cryopump arrays. A message is dis-
played on the keypad/display warning you about this potential problem.
The fourth parameter of the CONTROL function allows you to open or
close the rough valve as shown in Figure 3-43.
Figure 3-43: Rough Valve Open/Closed Display
Last
Next
Clear
MONITOR
REGEN
SERVICE
CONTROL
RELAYS
HELP
oo
ON
-BOARD
®
Enter
1
2
3
4
5
6
7
8
9
-
0
.
ROUGH V OPEN
Last
Next
Clear
MONITOR
REGEN
SERVICE
CONTROL
RELAYS
HELP
oo
ON
-BOARD
®
Enter
1
2
3
4
5
6
7
8
9
-
0
.
ROUGH V CLOSED