User`s guide

4-2
4.1.3 Establishing Cellular Service for CSD
A cellular account must be activated with the local service provider prior to placing a
DCM-200 into service. Many GSM service providers offer some sort of data support, but
their marketing focus may be on Internet connectivity or short-message services (SMS,
used to send text messages to and from cellular phones). This does not necessarily
mean that they support all forms of data transfers. The service provider must support
asynchronous circuit-switched data (CSD) exchange at 4800 or 9600 baud. The baud
rate must match the baud rate of the central computer’s modem. Sometimes this
capability may be included as part of a standard voice package, or it may be an add-on
feature at extra cost. It may be necessary to contact the technical support department of
the provider to determine if CSD is supported.
One consideration when ordering service is the frequency of calls to and from the DCM-
200. A call that requests all of the data from the electric meter could take as long as 15
minutes. Each service provider offers different packages that include a fixed number of
minutes per month for a fixed price. However, when this number is exceeded, the cost
per each additional minute can be very high. Also, there are variations in the way
“minutes” are measured. For example, a call lasting 1 minute 10 seconds may be
considered to be a 2-minute call by some providers. It might be possible to purchase
less expensive packages that have additional “weekend” or “evening” minutes, and then
schedule the DCM-200 to place calls during those times. Some plans offer the 1
st
minute free when the phone is called. This might be advantageous if the DCM-200 is
going to be called often by the central computer.
Another consideration when ordering service is the location of the DCM-200 with respect
to the service provider’s network. It is best to describe where the units will be located
and where they will be calling, otherwise you could be charged “roaming” or long-
distance fees. Some providers offer free long distance or no roaming charges as part of
their basic plans.
The final consideration is the direction of the calls. If the DCM-200 is to originate calls,
then the service must support “mobile-originate” service. If the unit is to receive calls,
then “mobile-terminate” service is required.
The service provider will need the following information:
• Type of cellular service desired. In this application it would be with async circuit-
switched data (CSD) mode enabled.
• Data mode is to support 4800 or 9600 baud operation. This rate must match the
speed of central computer’s modem.
• Mobile-originate and/or mobile-terminate service.
• Number of minutes per month.
• Location of the DCM-200 and the location of central computer (to determine if
“roaming” or long distance charges apply).
• The service provider may need to know the “IMEI” number printed on the radio.