WHEATBRIDGE ::Data Acquisition: Global Options

COLLECTING DATA: HONG KONG TO BISMARK, ANCHORAGE TO CAPE TOWN

Our experience with ethernet data collection--in other words multithreaded network data transactions--is both broad and deep. We have worked on a number of projects in which we convert serial, one-at-a-time transactions into simultaneous ethernet polls. What once might have taken 20 minutes to poll a chain of devices (or computers) we can now accomplish in seconds, spawning hundreds of threads simultaneously that each collects a piece of data over an intranet, fiber network, or the Internet itself. We can help you collect data globally--from a temperature sensor in Hong Kong to a web posting in Bismark, North Dakota--using simultaneous, asynchronous connections.

When speaking of industrial process telemetry, one has to mention SNMP, which stands for Simple Network Management Protocol. There is nothing simple about SNMP. It is a family of protocols that provide a means for monitoring and controlling networked devices. SNMP devices are usually referred to as "smart" devices. Using SNMP makes device management more involved and its installation more complex.

SNMP is nevertheless very powerful and it permits active management tasks such as modifying and applying a new configuration through remote modification of variables, which are organized in hierarchies. These hierarchies and other metadata (such as type and description of the variable), are described by Management Information Bases (MIBs). Usually these MIB files are based on standards, such is NTCIP. We have experience building a number of drivers for these types of devices, such as matrix or variable message signs, encoders and decoders, and switches. Devices of these kinds have hundreds of configuration options.

We also have experience developing data collection drivers for less complex proprietary systems, such as camera pan-tilt-zoom-and-focus. We have written camera device drivers for RS485 (and ethernet IP to Serial) for Pelco D, Pelco P,AD422, Fastrax, DynaColor, JVC, Panasonic (STX/ETX) protocols.

Other device protocols allow an application to communicate with the sensor over a dedicated TCP/IP link and simple ASCII string transactions. They allow for the transfer of data (per time-interval), event data, and other data strings as well as the alteration of some sensor configuration settings, such as sensor clock time, duration of time or interval for data aggregation, baud rate, reconnect retries, inter-message delays, HDLC groups and addresses, host address, names, and data classification.

We build agents launched as triggers within databases such as MS-SQL, and we also build them as services accessible through WMI protocols, web services, stand-alone pollers, port listeners, and database tables shared by multiple users.

Nevertheless, implementation from a developer's point of view remains fairly straightforward.