Hold Functions With; Configuring Refractometer System; Configuring Relays - Vaisala K-PATENTS PR-23 Series Instruction Manual

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6.2.7 Hold functions with DD-23
The Digital Divert Control System DD-23 uses the displayed concentration value in its
decision logic. Due to this, the external hold functionality must not be used with a
DD-23, as it could potentially render the system unsafe by freezing the measurement
result.
The "hold during wash" must be used with DD-23. Otherwise the signal damping com-
bined with low nD values caused by the wash process may give erroneous information
to the DD-23 after the wash is over.
The selection of tolerance time with DD-23 requires a careful risk analysis. The use of
the tolerance time functionality does not slow down the response of the instrument
when the instrument is in
function alarm in the DD-23 in case the process pipe becomes empty or some other
reason makes the optical image impossible to interpret. The recommended value for
tolerance time is 5 seconds when a DTR is used in a DD-23 system.

6.3 Configuring refractometer system

The Indicating transmitter has two built-in 4–20 mA outputs (
), two relay contact outputs (
OUTPUT 2
(
SWITCH 1, SWITCH 2, SWITCH 3, SWITCH 4
signed to either sensor A or sensor B.

6.3.1 Configuring relays

For the electrical properties of the built-in relays, see Section 3.3.3. Each of the two
relays can be configured individually to either Sensor A or Sensor B, i.e. 0–2 relays can
be assigned to a sensor. Relays can also be opened and closed manually, mainly to test
them.
To configure the relays, follow the instructions below:
1. Select
5 CALIBRATION
2. Select from the Calibration menu.
3 RELAYS
3. Select the relay, either
4. In the Relay menu (see Figure 6.6) select
either Sensor A or Sensor B.
Note: The current assignment of the relay is shown at the bottom of the Re-
lay menu display, e.g. Figure 6.6 Relay 1 is assigned to Sensor A with function
Low limit.
5. In the relay menu, select
1
NOT DEFINED
2
NORMAL OPERATION
. It does, however, slow down the mal-
NORMAL OPERATION
RELAY 1, RELAY 2
). Each of these resources can be freely as-
from the Main menu.
or , to be configured.
1 RELAY 1 2 RELAY 2
1 SENSOR
to set the relay function:
2 FUNCTION
Factory setting.
Closed contact if diagnostic message is
during (see Section 6.3.2). The contact is also
TION HOLD
closed when message is
PR-23 instruction manual
mA OUTPUT 1, mA
), and four switch inputs
to assign the current relay to
NORMAL OPERA-
.
NO SAMPLE