Endress+Hauser Liquiline Control CDC90, Operating Instructions Manual

Page: 87 / 118

Liquiline Control CDC90 Operation
Hauser 87
Function = Controller
Function Options Info
Actuator type Selection
• None
• Unipolar(-)
• Un)
Factory setting
None
Here you specify what part of the controller
should power the relay.
Un) is the part
of the manipulated variable which the controller
uses to increase the process value (e. g. for
heating purposes). On the other hand, select
Unipolar(-) if you want to connect an actuator
to the relay that causes the controlled variable to
drop (e. g. for cooling purposes).
Cycle duration
Operating mode = PWM
Shortest turn-on time to
999.0 s
Factory setting
10.0 s
‣
Specify the cycle duration within which the
duty cycle should be varied (only PWM).

The settings for Cycle duration and Shortest turn-on time mutually affect one another. The following
applies Cycle duration ≥ Shortest turn-on time .
Shortest turn-on time
Operating mode = PWM
0.3 s to Cycle duration
Factory setting
0.3 s
Pulses that are shorter than this limit value are
not output in order to conserve the actuator.
Maximum frequency
Operating mode = PFM
1 to 180 min -1
Factory setting
60 min ‐ 1
Maximum number of pulses per minute
The controller calculates the pulse duration
based on this setting.
Outputting diagnostic messages via the relay
If a relay is defined as a diagnostic relay ( Function = Diagnostics ), it works in the "fail-
safe mode" .
This means that the relay is always energized ("normally closed", n.c.) in the basic state if
an error is not present. In this way it can also indicate a drop in voltage, for example.
The alarm relay always works in the failsafe mode.
You can output two categories of diagnostic messages via the relay:
• Diagnostic messages from one of the 4 Namur classes
• Diagnostic messages which you have individually assigned to the relay output
A message is individually assigned to the relay output at 2 specific points in the menu:
• Menu / Setup / General settings / Extended setup / Diagnostics settings / Diag. behavior
(device-specific messages)
• Menu / Setup / Inputs /<Sensor>/ Extended setup / Diagnostics settings / Diag. behavior
(sensor-specific messages)
Before being able to assign the relay output to a special message in Diag. behavior
you must first configure Outputs /Relay x:y or / Alarm relay / Function = Diagnostics .