Tehama Wireless Design Group TW112 MDT TW112 User Manual User Guide
Tehama Wireless Design Group Inc. MDT TW112 User Guide
User Guide
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Tehama System (3rd Gen.) Installation Overview
General Description
The Tehama AMR system consists of three device types to remotely monitor various
environmental and utility readings and provide the data to a central database or PC for formal
presentation and reporting. Metering Data Transceiver (MDT TW-111 and TW-112) devices will
be placed in all locations requiring local monitoring of data. The MDT devices will transmit time
stamped data to the DCAP device (DCAP TW-222), which receives the data and stores it in a
Database. The database information is available over Ethernet on the local LAN or the Internet.
For MDTs that are out of range from the DCAP, Repeater devices (RPT TW-222) are added in
appropriate locations to relay the data between MDTs and the DCAP.
The system operates in the 915MHz ISM bands using off-the-shelf Semtech RFIC radios. The
system operates either as a FHSS over 60 narrow band frequency channels, incorporating a
bidirectional communication link with Acknowledge (ACK) messages to ensure all data reaches
the DCAP or as a DTS non-hopping spread spectrum with 842kHz Bandwidth. The MDTs are
battery operated, bursting data packets at pre-programmed times then shutting down to conserve
battery life, estimated to exceed 5 years. The DCAP and Repeater units are line powered.
With a typical MDT transmission rate of one per hour (four per hour for Time of Use applications),
a single DCAP can accommodate up to 1000 MDTs. There is no limit to the number of repeaters,
though an average installation where MDTs are spread out in each living space will require one
Repeater for every 20-30 MDT/MDTs.
Figure 1: Typical System
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A system consists of two or three types of hardware, and a software program:
• A DCAP Unit
• A variable number of MDT units, each with 2 AA batteries
• A variable number of Repeater units (optional, depending on size of installation) with
external DC power supply.
• Tehama Configuration Utility (CIT) running on a PC
Warning
NOTE: THE MANUFACTURER IS NOT RESPONSIBLE FOR ANY RADIO OR TV INTERFERENCE
CAUSED BY UNAUTHORIZED MODIFICATIONS TO THIS EQUIPMENT. SUCH MODIFICATIONS
COULD VOID THE USER’S AUTHORITY TO OPERATE THE EQUIPMENT
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Tehama Configuration & Installation Tool (CIT)
You should have received a copy of the Tehama Configuration and Installation Tool (CIT)
software. If not, please contact support@tehamawireless.com and request the link. The CIT
runs on a Windows based PC. More detailed information can be found in our training class
materials or the Tehama QuickStart Guide available on our web site.
The tool can be run on the PC either prior to or during a site installation, or when new MDTs are
added to a system. The tool is used to add configuration data to the database. Examples of
configuration data include the name, type, and location of equipment an MDT is connected to,
and alarm trigger settings for the different MDTs.
Data Collecting Access Point (DCAP) Setup
This step configures the Internet settings for the DCAP and lets you set unique passwords for
remote access.
• Screw in the Antenna that came with the unit.
• Power up the DCAP with the supplied power adaptor.
• Attach the DCAP to your local LAN with the supplied Ethernet cable.
• Launch the CIT tool on the PC
• If a static IP or non-default passwords are desired, attach the supplied USB cable to your
computer and to the DCAP. If this is the first time attaching to a DCAP, Windows may
respond with a “found new hardware” message. Follow the steps to let Windows download
the driver software. Your PC will need to be connected to the Internet to download the
drivers.
• Go to the DCAP -> Configure via USB menu item. The Serial Port field should be
automatically populated with the correct COM port
• Click on the Get button to see the current settings
• DCHP (Dynamic IP Address) is the default. If you want a static IP, select static and fill
out the extra fields.
• Set the MySQL database passwords for both users and click “Set”. Clicking on the
“Default Vals” button will fill the fields with the factory default passwords. This is
provided as a convenience if password security is not an issue (for example in an
evaluation system).
• Click on the “Create a Site Entry” button to auto-fill a Site entry with the information
from this panel.
• Unplug the USB cable. It is not needed again unless you need to change the IP address
or the database passwords at a future time.
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MDT Configuration
All MDT come from the factory with a default factory-set configuration; there is no user
changeable setup of an MDT. It need only be connected to the meter and turned on. A
number of different MDTs are available, our most popular being a single pulse input unit with a
one-hour transmission interval. See our web site for other variations available.
MDT and Repeater devices come from the factory in a powered off state. They can be powered
on using a hidden button under the Tehama Wireless logo.
The big circle in the photo below shows where the hidden button is located on the enclosure. It
may take a few times to get the feel of the button, but an LED to the left gives you feedback
when the button is pushed.
Turn ON or Off (MDT only):
- Press & hold button until LED blips off, then release.
Power-up LED Flashing:
- Listening for DCAP or Repeater: LED flashes slowly
- Trying to Connect to DCAP: Flashing changes from slow to fast
- Successful Connection: LED stays solid for 10 seconds.
- If NOT successful, LED goes out without the 10 second on
Check the status of an MDT or Repeater by tapping the button
- Unit is OFF: Two flashes after button is released
- Unit is Asleep and NOT connected to Network: One flash only
- Unit will wake up within one hour and try to re-connect to
Network. This is usually an indication of poor placement or
inadequate Repeater coverage.
- Unit is Connected and operating normally: LED on for 10 seconds
- Green is good link, Orange an OK link, Red is poor link
Reset Count (MDT Only): Press and hold button until power-up
flashing sequence starts (12-15 seconds)
MDT to Meter wiring
Refer to our many wiring diagrams on our web site for wiring instructions from the many
different meters available.
Device Placement
Warning: All radio devices should be placed at least 8 inches (20 cm) away from
people in order to minimize RF exposure.
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With the DCAP Unit powered up, the repeater backbone should next be placed. Start with units
closer to the DCAP/AP, and use the LED feedback indication to verify the range is acceptable.
At first just the minimum numbers of repeaters can be placed, and it is necessary that they be
within range (solid 10 second LED “flash” when button pushed) for the backbone to be reliable.
Repeater to Repeater (or DCAP) range in open field scenarios is in excess of 1/2 mile, however
building construction materials, terrain, and poor location choices can reduce this down to
hundreds of feet or less.
Once the initial Repeater placement is complete, the MDT placement phase begins. Again the
LED feedback can be used to verify that MDTs are communicating with the network. Additional
repeaters can be placed in areas where MDTs are unable to connect to the backbone. MDT to
Repeater (or DCAP) range in open field scenarios is in excess of 1500 feet, however building
construction materials, terrain, and poor location choices can reduce this down to a hundred
feet or less.
The CIT software can also be used in the placement phase to provide more detailed information
such as Link Quality and Signal Strength readings generated by MDT and Repeaters.
Mounting Guidelines
Units should never be placed directly on a metal surface or within a metal enclosure. Mounting
on a metal surface will significantly affect the radio performance of the device, be it an MDT or
a Repeater.
Recommended placement
- Mount on nearby wall away from meter and copper /metal piping
or conduit.
- RF performance is best when mounted on wallboard
- Use keyhole shape to mount on screw in wall
- Designed for #6 Drywall screw
- Separate case to tighten screw if desired
- Note Antenna Pattern shown on the right.
- Radio signal slightly attenuated along the long axis of the MDT
case
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FCC/IC Compliance information for
MDT TW-111, MDT TW-112, RPT TW-222 and DCAP TW-222
Contact:
Tehama Wireless
2607 7th Street, Suite G
Berkeley, CA 94710
415.495.7344
info@TehamaWireless.com ©2017 Tehama Wireless Design Group
www.TehamaWireless.com Rev.1709
Users in the US
The device complies with Part 15 of the FCC rules. Operation is subject to the following two
conditions:
(1) this device may not cause harmful interference, and
(2) this device must accept any interference received, including interference that may
cause undesired operation
Users in Canada
This device complies with Industry Canada license-exempt RSS standard(s). Operation is
subject to the following two conditions:
(1) this device may not cause interference, and (2) this device must accept any interference,
including interference that may cause undesired operation of the device.
This equipment complies with IC radiation exposure limits set forth for an uncontrolled
environment and meets RSS-102 of the IC radio frequency (RF) Exposure rules. This
equipment should be installed and operated keeping the radiator at least 20cm or more away
from person's body (excluding extremities: hands, wrists, feet and ankles).
Pour les usagers résidant au Canada
Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio
exempts de licence.
L'exploitation est autorisée aux deux conditions suivantes :
(1) l'appareil ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter
tout brouillage radioélectrique subi, même si le brouillage est susceptible d'en compromettre le
fonctionnement.
Cet équipement est conforme aux limites d'exposition aux rayonnements énoncées pour un
environnement non contrôlé et respecte les règles d'exposition aux fréquences
radioélectriques (RF) CNR-102 de l'IC. Cet équipement doit être installé et utilisé en gardant
une distance de 20 cm ou plus entre le dispositif rayonnant et le corps (à l'exception des
extrémités : mains, poignets, pieds et chevilles).