The CIMScan architecture is very straightforward and easily understood. The simple diagram below shows how it works.

Every sensor has a unique serial number. The serial number and the measurement value are sent to a remote data acquisition device called an eLink. The eLink, in turn, assembles the measurements into messages and forwards them to the CIMScan server ether via direct Internet connection, cell phone data link, or via satellite.

HOW IT WORKS

CIMScan provides three methods for linking remote sites with the server. The least expensive way is to interface directly to the Internet using a DSL router. If DSL is not available, a cellular (GSM) data link can be use. For remote sites outside of cellular telephone coverage, a link through a low earth orbit satellites can be used. These satellites constantly circle the globe at an altitude of 650 to 800 KM and relay short messages uploaded from remote devices. The diagram below shows all three communications possibilities.

1. The outputs from analog and pulse output sensors are converted to a digital value using our I/O Pods. Specialized instruments also take measurements, convert them, and hold the result for transmission to the host eLink controller over a common 4-wire Modbus network.
2. Additional devices can be linked to the network using a pair of wireless transceivers. Line of sight distances from 1-12 miles (1-20 KM) can be achieved.
3. The eLink periodically polls each of the devices attached to the Modbus network and requests their measurement data and assembles it into packets which are stored for transmission to the server.
4. The eLink waits for a satellite to come into range and then uploads uploads the accumulated measurement packets in a message and the satellite stores it. As the satellite moves into range of an earth station, the two establish communications and the satellite downloads all of its accumulated messages. The earth station processes the messages and forwards them to the appropriate appropriate CIMScan server via the Internet.
5. The eLink forwards accumulated message packets to the cellular telephone service provider as SMS messages. The service provider then forwards the messages to the appropriate CIMScan server via the Internet.
6. A direct DSL connection allows the eLink to send measurement data directly to the server via TCP/IP messaging over the Internet.
7. All messages have checks included to insure data integrity.  

DA-4X FOR SATELLITE AND CELLULAR NETWORKS 

The DA-40 eLink has been specially designed to gather measurement data at remote unattended sites and send it back to a CIMScan server via the ORBCOMM Low Earth Orbit (LEO) satellite system. The unit is housed in a NEMA-4X rated enclosure which is usually housed, along with the power system and possibly the data acquisition components, in another waterproof enclosure. DA-44 uses a GSM modem to transfer data to the server via a cellular telephone network. Other than the fact that the antenna connector is RPSMA rather than TNC, the DA-40 and DA-44 are identical as far as the user is concerned.

A variety of solar power systems, like the one shown in the photograph above, are available to power the DA-40/44. The general specifications for the DA-40/44 are shown below.

• Power Requirements: 10-18Vdc Unregulated 2A Max
• Power Consumption: 18W (xmit), 1W (rec), 3W (avg)
• Operating Temp: -40°C to +85°C
• Enclosure: Polycarbonate NEMA-4X Rated
• I/O: PodNet or Modbus RS-485 Serial Port

DA-07 ELINK FOR DIRECT INTERNET CONNECTION

The DA-07 eLink is a very flexible remote data acquisition controller for the CIMScan® monitoring system. The unit can continuously gather measurement data from up to 64 inputs in up to 32 Modbus-RTU devices on a single multi-drop RS-485 communications network. Both instantaneous rates as well as accumulated totals and other hourly statistics are acquired.

The DA-07 sends the measurement data to a CIMScan server computer using the standard TCP/IP protocol over a Local Area Network (LAN) or the Internet. The unit has the ability to buffer up to 5,000 measurements if a LAN fault occurs or the server fails for any reason. The buffered measurements are automatically forwarded to the server when communications is restored.

Click here to download a PDF datasheet on the DA-07 eLinnk Controller.

DATA ACQUISITION UNITS

Our standard Modbus-based I/O Pods can be used with the DA-07/40/44 to interface with analog (DC voltage and 4-20 ma current loop) and pulse/frequency outputs from a wide variety of sensors/transmitters.

The analog input devices have 16-bit A/D converters.

RM-12 WIRELESS NETWORK INTERFACE

CIMTechniques' RM-12 spread spectrum radio modem adds wireless networking capability to any CIMScan system.  The modem can be used indoors or out and operates in the 900 MHz unlicensed band.  As with any I/O Pod, the RM-12 operates from an unregulated 10-30 Vdc power source and can survive in a typical, harsh industrial environment.  Remote operation from battery or solar power is easily accomplished.

The RM-12 is housed in a waterproof (designed to be IP-65 rated), die-cast aluminum enclosure.  A waterproof compression fitting is provided to seal the power and signal cable entry point. The unit can be easily surface or pole-mounted.

Click here to download a datasheet in PDF format on the RM-12.

POWER SUBSYSTEMS

A variety of power subsystems are available for powering the DA series controllers in a remote application. These include various photovoltaic arrays with rechargeable batteries to meet any application requirements. Contact CIMTechniques sales with your exact requirements.

MODBUS-BASED SENSORS/TRANSMITTERS

The following low power Modbus-based sensors are available for direct connection to the DA-07/40/44.

THIRD PARTY INSTRUMENTS

Virtually any sensor/instrument that produces and analog or digital (pulse) output can be connected to the DA-40 through one of the I/O Pods. Also, any instrument that communicates over RS-485 using the Modbus-RTU protocol can be used.