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YSI DIQ/S 182-MOD System 182 User Manual

Page 92

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Relay outputs

System 182

6 - 6

ba76025e01

02/2012

Monitoring limiting

values using one or two

relays

Fig. 6-1

Switching points for relays with the function of a limit indicator

A switching delay (t) can be set up for each relay for switching
processes. This is the time period for which a limiting value must be
exceeded before the relay switches. This prevents frequent switching if
the measured values are close to the limiting value.

1

Upper limit value (relay 1) exceeded

2

Selected switching delay t1 for relay 1 expired
Relay 1 switches

3

Hysteresis for upper limiting value (relay 1) undercut

4

Selected switching delay t1 for relay 1 expired
Relay 1 switches back

5

Lower limit value (relay 2) undercut
Selected switching delay t2 for relay 2 expired
Relay 2 switches

6

Hysteresis for lower limiting value (relay 2) exceeded
Selected switching delay t2 for relay 2 expired
Relay 2 switches back

Time

Measured
value

UL

LL

Hysteresis UL

Hysteresis LL

3

5

Relay 1

Relay 2

4

1

2

t1

t1

6

t2

t2