Analog Inputs - Phoenix Contact Nanoline Series User Manual

Nanoline
60
PHOENIX CONTACT

Analog inputs

Each analog input must be checked for accuracy.
Two checks must be made:
– Destination – Once a value is observed at the device, a corresponding change must be
observed (regardless of accuracy) at the Nanoline to ensure the sensor is connected to
the right channel.
– Calibration – All the range and offsets or tables for the sensor are set in the software
during the application stage. However, due to line losses, the offset may require
adjustment.
For example, the use of a digital thermometer allows the checking of temperature
sensors. The temperature should be taken as close to the sensor as possible and
checked for accuracy with the reading displayed on the Nanoline. If there is a difference
in readings, a +/- change to the offset can be made to compensate.
Depending upon the input type, measurements of voltage, current, resistance,
humidity, speed, pressure, etc., may need to be checked in a similar fashion.
Where field devices are used, it is normal to provide the controller with a variable voltage or
current signal between 0-5 V DC, 0-10 V DC, 0-20 mA or 4-20 mA. If the device is
commissioned independently, the signal can be measured and compared with the signal
range (e.g., 0-1000 Pascals) and a calibration check made against this value witnessed at
the controller.
4.1.4.7 Control strategy
After all inputs and outputs are functioning correctly and accurately, the control strategy can
be commissioned.
The basis of this stage relies upon the skill of the Application Engineer interpreting the
customer/consultant's specification correctly.
It is the Commissioning Engineer's job to verify that the application meets the specification.
Therefore, an intimate knowledge of the specification is required by the Commissioning
Engineer. Alterations to parameters that are site-dependent must be entered to maximize
the efficiency of the controls employed.
Features, such as automatic mode, manual mode, diagnostics, looping in controls,
destinations of blocks, order of execution of flow charts, messages and data items, need to
be verified at this time.
Every step of the application must be checked to ensure the response is correct as
designed and specified. This part of the commissioning requires knowledge in both controls
and controller logic.
The commissioning of the network falls into the following stages.
– Installation
– Wiring and hardware
– Program application execution
Ethernet installation checks
The controller must be fully operational and the network cable installed. Shielded cable
must be grounded/earthed at one point per leg.
Cable routing must be kept separate from any AC power wiring. The route of the cable
should be verified against the network layout drawing and all input and output destinations
tagged on the cables at each node.
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