Teledyne 7120 - NDIR analyzer - Manual (Page 20)

2 Installation Model 7120
2-12
Teledyne Analytical Instruments
39 Range 2 ID Contact
19 Range 3 ID Contact
18 Range 3 ID Contact
34 Range 4 ID Contact
35 Range 4 ID Contact
2.3.3.5 Network I/O
A serial digital input/output for local network protocol. At this printing,
this port is not yet functional. It is to be used in future options to the instru-
ment.
2.3.3.6 Remote Valve Connector
The 7120 is a single-chassis instrument, which has no Remote Probe
Unit. Instead, the Remote Valve connector is used as another method for
controlling external sample/zero/span gas valves. See Figure 2-7.
Figure 2-7: Remote Probe Connector Pinouts
The voltage from these outputs is nominally 0 V for the OFF and
15 V dc for the ON conditions. The maximum combined current that can be
pulled from these output lines is 100 mA. (If two lines are ON at the same
time, each must be limited to 50 mA, etc.) If more current and/or a different
voltage is required, use a relay, power amplifier, or other matching circuitry
to provide the actual driving current.
In addition, each individual line has a series FET with a nominal ON
resistance of 5 ohms (9 ohms worst case). This could limit the obtainable
voltage, depending on the load impedance applied. See Figure 2-8.