Teledyne 4020 - Hydrocarbon analyzer - Manual (Page 37)

Total Hydrocarbon Analyzer Installation
Teledyne Analytical Instruments 21
(Reset by pressing the STANDBY button to remove
power. Then press STANDBY again and any other
button except SYSTEM to resume
Further detail can be found in Chapter 4, Section 4.5.15.
Table 3-4: Alarm Relay Contact Pins
Pin Contact
45 Threshold Alarm 1, normally closed contact
28 Threshold Alarm 1, moving contact
46 Threshold Alarm 1, normally open contact
42 Threshold Alarm 2, normally closed contact
44 Threshold Alarm 2, moving contact
43 Threshold Alarm 2, normally open contact
36 System Alarm, normally closed contact
20 System Alarm, moving contact
37 System Alarm, normally open contact
3.3.3.6 D IGITAL R EMOTE C AL I NPUTS
The digital remote calibration input accepts 0 V (off) or 24 VDC
(on) for remote control of calibration. (See Remote Calibration
Protocol below.) See Table 3-5 for pin connections.
The remote cal inputs are shared by the digital range selection mode.
When the user selects the digital range selection mode, the input is used
by the analyzer for range selection. See Section 4.6.13.3 Digital Mode.
Zero: Floating input. A 5–24 V input across the + and –
pins puts the analyzer into the Zero mode. Either side
may be grounded at the source of the signal. A 0–1
volt across the terminals allows Zero mode to
terminate when done. A synchronous signal must
open and close the external zero valve appropriately.
Span: Floating input. A 5–24 V input across the + and –
pins puts the analyzer into the Span mode. Either
side may be grounded at the source of the signal. A