Models 947, 948 and 960 Leak Detectors Operations and Service Manual
2-10
2.3.2 BCD J121 Outputs
Table 2-3 provides the J121 output connections.
23
Ready
Active High
Active when system is operating
(inverse of “Not Ready”).
25
Ground return for J120 only
27, 28
+24 VDC for Output Sourcing
Table 2-3
J121 Output Summary
Pin on
J121
Signal Name
Momentary
or Level
Description
1, 2
Ground for J121
3
LSD A
Active High
BCD Leak Rate
4
LSD B
Active High
BCD Leak Rate
5
LSD C
Active High
BCD Leak Rate
6
LSD D
Active High
BCD Leak Rate
7
MSD A
Active High
BCD Leak Rate
8
MSD B
Active High
BCD Leak Rate
9
MSD C
Active High
BCD Leak Rate
10
MSD D
Active High
BCD Leak Rate
11
LSD A
Active High
BCD Leak Rate
12
LSD B
Active High
BCD Leak Rate
13
LSD C
Active High
BCD Leak Rate
14
LSD D
Active High
BCD Leak Rate
15
MSD A
Active High
BCD Leak Rate
16
MSD B
Active High
BCD Leak Rate
17
MSD C
Active High
BCD Leak Rate
18
MSD D
Active High
BCD Leak Rate
20, 21
+24 VDC for Output Sourcing
24, 25
Ground for J121
Table 2-2
J120 Input Connections (Continued)
Pin on
J120
Input Name
Momentary or Level
Description