Customer Solutions

Lookout and FieldPoint Provide Around-the-Clock Monitoring of Biotech Experiment Storage Environments

Author(s):

Ted Brunzie, Data Science Automation, Inc.; David Reed, Data Science Automation, Inc.

Industry:

Life Science

Product:

Compact FieldPoint, Data Logging, Distributed I/O, FieldPoint, Lookout

The Challenge:

Create an automated system to monitor and log equipment temperatures for up to 500 sensors located throughout a state-of-the-art biotechnology research facility. The system must be capable of operating unattended 24 hours a day, and must alert technicians via pager to any out-of-range alarm events.

The Solution:

Acquire and condition the sensor data remotely, using National Instruments FieldPoint nodes located throughout the facility, then communicate the data to a central PC via RS-485. Perform limit checking, logging, and trending of the data with National Instruments Lookout 4 software.

Introduction
In 1999, Genetic Therapy, Inc. (GTI) constructed a new building in Gaithersburg, Maryland to support biotech research. This facility needed a system to provide unattended monitoring and data logging of "microenvironments" used to culture and preserve experiments. Protecting this valuable research meant continuously evaluating a variety of alarm conditions and automatically notifying on-call technicians of equipment failures.

System Configuration
Initial requirements for facilities monitoring called for equipping 383 devices with sensors for measuring temperatures, gas concentrations, and alarm relays. Monitored devices included liquid nitrogen (LN2) dewars, freezers, refrigerators, and cell culture incubators scattered throughout 72 laboratories, storage areas, and hallways on two floors of the building and a separate site nearby, called the G&A building. The widespread physical distribution of the equipment made it necessary to divide the collection of sensors into nine groups or "nodes," each surrounding a remote data acquisition unit.

National Instruments FieldPoint was selected for the remote data acquisition units, supporting the measurement of 362 individual 3-wire RTD temperature probes (measuring "80C to ambient), 11 voltages produced by incubator CO2 concentration monitors (nominally 50 mV), and 21 digital relay closures provided by LN2 tank monitoring units. These channels were acquired using 46 FP-RTD-122 units, 2 FP-AI-110 units, and 2 FP-DI-301 units with external 24 VDC supplies to provide electrical continuity.

The acquired data were communicated to a central Control PC via nine FP-1001 RS-485 network modules on four full-duplex shielded cables, one of which was dedicated to the G&A building. The nine nodes, each consisting of a network module and five or six data acquisition modules, were mounted above the drop ceiling in the hallways for easy maintenance access. The nodes were powered by PS-3 float chargers in parallel with 12-Volt 7-Ahr UPS batteries to ensure continuous operation during power outages.

During building construction, a total of 496 4-wire cables (including 102 spares) were pulled through the ceilings from the data acquisition nodes to the locations of the monitored devices. These cables were fed down the walls to wall plates containing from one to six DB-9S jacks, each with a "Wall Plate Number" denoting room, node, and a serial number. Within the rooms, an additional 3-4 meters of cable connected the corresponding DB-9P plugs to one of the three types of sensors located within the equipment being monitored. Since every wall jack connected to a specific FieldPoint input module, each sensor type used a different set of wires within the cables; configurations were chosen to ensure that a complete circuit formed only when the proper sensor was connected.

System Software
National Instruments Lookout was chosen for developing the Facility Monitoring System (FMS) software, in part because of its flexible, object-oriented nature. It promised fast development, easy modification, built-in data logging and trending, and transparent network connectivity, supporting a client-server architecture. The Enterprise version of Lookout 4.0 with 500 I/O points and four client connection mlicenses covered the requirements for channel count and remote monitoring of the facility by client PCs.

Each of the 500 sensor channels defined in the software was required to have a Hi and Lo alarm limit, both with associated delay periods to provide hysteresis and prevent nuisance alarms. Temporary suspension, used while equipment is off-line for servicing, ensures that alarming will automatically be re-enabled. Scheduled suspension prevents false alarms during scheduled events, such as freezer defrost cycles. During normal operation, alarm delays compensate for researchers opening doors and for closed-cycle refrigerators making brief excursions beyond alarm limits; only sustained operation outside limits results in alarm events.
The channel configuration panel also provides access to a real-time/historical trend plot and another panel with device ownership information. An icon to the left summarizes the "channel state" using a combination of color and shape to indicate if the channel is nominal, above or below limits, in alarm above or below limits, suspended, or if alarm checking is disabled.

Presenting and navigating through such a large number of configurable points called for an innovative method of managing the user interface. The FMS Client Process provides nearly all the operator interface to the system, mainly in the form of a hierarchy of floor plans. Rooms in the facility containing any microenvironments in an alarm state will flash red on the main panel. Otherwise, they show a steady yellow if an environment is out of limits (but not long enough to qualify as an alarm) and white if everything within is nominal.

When an operator clicks the mouse anywhere on a room image, a panel similar to Figure 4 appears, providing additional detail. Monitored devices are represented by an icon showing the channel serial number, the device name, its state icon, and its current value. These icons flash red or yellow as appropriate to draw attention. Clicking on a device icon will open the Channel Configuration panel. Logging and alarm control for all 500 channels was made easy by connecting the acquired channels to a single data table object. Custom alarm objects made possible the sophisticated alarming scheme that would evaluate and page out only legitimate alarm states to on-call technicians, using a numeric code to specify the device type, current value, room number, and serial number. In all, the features of Lookout and FieldPoint made the difference in creating a flexible system fit within a tight schedule and budget.

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