Honeywell 9782 Series manual Wiring a Device to the Relay Indicating Output Range Status

Conductivity/Resistivity Analyzer/Controller

6.4.3 Wiring a Device to the Relay Indicating Output Range Status

Introduction

If the automatic output range change feature is selected during I/O setup, one relay is dedicated to this function. The relay can be used to control an indicator, or to switch the output to a second channel of a multipoint recorder when the range change occurs (see Figure 6-2). Check the current relay assignments as described in Section 5 to determine whether a relay was assigned to this feature.

This feature closes contacts NC-COM when the output is scaled to the low range (Range 1 in Figure 6-2) and closes contacts NO-COM when scaled to the high range (Range 2 in Figure 6-2).

Interconnections

The range change capability illustrated in Figure 6-2 is accomplished with interconnections shown in Figure 6-3. Similar range identification could be obtained using a 2-pen or event-pen recorder.

Point 1/Terminals 1 - low range (0-1μS/cm)

Point 2/Terminals 2 - high range (0-10 μS/cm)

Resistors “R” across the recorder inputs are needed to ensure that the unused point will remain at the low end of scale. The resistance value can be anything from 500 ohms to 1 Mohm.

Time

(simulated condenser leak)

Range 1	0	.2	.4	.6	.8	1.0
Range 2	0	2	4	6	8	10

a/n 23178

Figure 6-2 Sample Multipoint Recorder Chart Illustrating Auto Output Range

Change for Steam Condensate Monitoring

6-10 9782 Series Conductivity/Resistivity Analyzer/Controller - Operator’s Manual 7/99