Models 947, 948 and 960 Leak Detectors Operations and Service Manual
D-2
6
Parallel Enable
Active High
Enables rear panel
PLC Interface.
Input
7
Zero
200 msec high pulse
Begins Auto Zero routine.
Input
9
Auto Cal
200 msec high pulse
Begins Auto Calibrate.
Input
10
Decrement
200 msec high pulse
Decrements the exponent
when in manual ranging.
Input
11
Increment
200 msec high pulse
Increments the exponent
when in manual ranging.
Input
12
Auto Range
Active High
Automatically changes the
exponent to keep the reading
in range.
Input
14
Hold
Not used.
Input
15
Filament Fault
Active High
Active when the selected
ion source filament is
non-functional.
Output
16
Not Ready
Active High
Not ready to run – possible fault. Output
18
CAL OK
Active High
Active when last
CALIBRATE successful.
Output
19
Zeroing
Active High
Active when Auto Zeroing.
Output
21
Calibrating
Active High
Active when Auto Cal.
Output
23
Ready
Active High
Active when system is operating
(inverse of “Not Ready”).
Output
27, 28
+24 VDC for Output Sourcing
Output
Table D-2
Optional Discrete I/O Parallel Interface (J120) (Continued)
