4. Wireless Modem Setup
Cautionary Note:
In some cases the signal strength of the wireless network (e.g., GSM cellular
network) will not be very strong at the physical location where the Power Monitoring
Device (RTU) must be installed. Examples of such locations would be a remote area
outside the city where network coverage is poor, or an industrial building where thick
concrete walls or other factors have degraded the signal.
Please ensure that wireless network reception is available at the installation location
of your RTU during the design and proposal phase of your project. You can test this
by trying to use your own personal mobile phone near the location of the RTU. Also,
if you place your GPRS modem at the intended installation location and power it on,
there are diagnostic commands available through Windows Terminal programs (e.g.,
Hyperterminal) that will report the actual signal strength. Please consult the
documentation of your GPRS modem for more information.
In some cases, additional work will be required to allow the GPRS modem to access
the wireless network. For example, in the case where reception inside an industrial
building is poor, you may consider mounting an antenna on the roof of the building
and routing a cable from the antenna to the modem.
The modem used in this example is the MultiTech MultiModem GPRS modem
(Model: MTCBA-G-F4).
http://www.multitech.com/PRODUCTS/Families/MultiModemGPRS/
The following settings should be considered:
a) SIM card and mobile service provider: your wireless modem uses a SIM card
to connect to the cellular phone network. This card will be issued by the
mobile service provider. Please ensure that you have GPRS (Data Services)
enabled for your SIM card. Also, your mobile service provider should give you
a list of the Access Numbers (phone numbers) for your SIM card. In some
cases, different numbers are used for voice calls and data calls. For reading
meter data, the data access number is used.
b) Basic modem setup: generally speaking, most wireless modems can be
configured via the Serial Port (RS-232). Using a terminal program such as
TeraTerm or HyperTerminal, you can make a serial connection from your PC
to the modem. Please consult the manual for your modem for detailed
information on AT commands. In this example, we configure the Baud Rate of
communication (which affects the link between the modem and the ION
meter), the number of rings before the modem will answer, and other
parameters. The following text shows the required settings for the MultiTech
modem – these should be entered after powering up the modem:
(210 strony)
(237 strony)
(33 strony)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Komentarze do niniejszej Instrukcji