beautypg.com

Teledyne 9070 - O2 and CO2 Food package analyzer (preliminary) User Manual

Page 18

background image

The two 4 to 20 mA DC output channels are capable of driving into a 1000

Ω load.

Channel 1

(Oxygen %)

Load

Connect a maximum

load of 1000 ohms.

Output is 4 to 20mA

DC isolated.

Channel 2

Load (optional)

CH1 O/P+
CH1 O/P-
CH2 O/P+
CH2 O/P-

27
28

25
26

Figure 3.4 Connections for Transmitter Output Channels.

3.4

CONNECTING THE ALARMS

A common alarm, which should be connected for all installations initiates on alarms functions described below. Three
additional alarm relays are available for selectable functions as listed in Section 4.2 and 4.3. Each relay has normally
closed contacts. The contacts will open in alarm condition except for the optional horn function which operates with
normally open contacts. Relays are connected as follows:

Relay

Terminal

Numbers

Common Alarm

29 & 30

Alarm 2

31 & 32

Alarm 3

33 & 34

Alarm 4

35 & 36

Common Alarms All of the following conditions will cause a common alarm -

ADC Calibration Fail

DAC Calibration Fail

Oxygen Sensor Fail

Oxygen Heater Fail

Oxygen Sensor TC Open

Gas Pump Fail

Mains Frequency Check fail

Oxygen Gas Calibration Check Error

Carbon Dioxide Sensor Fail

Watchdog

Timer


The watchdog timer is a special alarm. It will force the common alarm to activate in the event of a microprocessor
failure. There will not be an alarm message displayed, but the Analyzer will reset.

Alarms can be accepted by either pressing the alarm button (viewing the alarm messages), or by temporarily closing a
switch connected to terminals 16 & 17, REM ALARM RESET.

Alarm relay 2 to 4 Select any one or all of the following for each relay. Refer to Section 5.5, steps 45 to 47

High oxygen

Low oxygen

Very low oxygen

Oxygen sensor under temperature

Calibration check in progress

Alarm horn function (Relay 4 only)

3.5

CONNECTING THE HORN RELAY

Page 18

Teledyne Analytical Instruments 9070 Oxygen Analyzer