4 limit indicator, Limit indicator, Section 6.4.4 – YSI DIQ/S 182-PR System 182 User Manual

Page 101

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System 182

Relay outputs

6 - 17

ba76024e01

02/2012

6.4.4

Limit indicator

Function

The characteristic of the limit indicator is laid down in the Limit value
UL
, Limit value LL, Hysteresis UL and Hysteresis LL settings. The
fundamentals of the function are described in the introductory chapter
(see section 6.3.2).

In order to set up the Limit indicator function for a relay output, the relay
output must be linked with a sensor (see section 6.2.1).

Settings

Setting

Selection/Values

Explanation

Limit values

UL main variable
LL main variable

UL adjoining var.
LL adjoining var.

Main variable
designates the actual
measured parameter
of the sensor (e.g.
pH, oxygen, etc.).
Adjoining variable
designates an
additional measured
parameter (e.g.
temperature).

Limit value UL

within the measuring
range (sensor-
dependent)

Any upper or lower
limiting value

Limit value LL

Hysteresis UL

0 - 10 % of the
measuring range

Hysteresis for upper
or lower limiting value

Hysteresis LL

Behavior at error

Open
Close
Unchanged

The relay opens,
closes, or remains
unchanged in case of
system errors or
sensor errors (see
page 6-25).

Action

Open
Close

Relay action

Switching delay

0 ... 3600 s

The time period for
which a limiting value
must be exceeded
before the relay
operates.
Prevents frequent
switching for
measured values that
are close to the
limiting value.

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