Today, fortunately, things are very different – and very
much better.
Multipurpose
or
Universal
Line Cards are in
common use, and each (like the CP-220A's REC-1 or
REC-11) can handle a wide range of formats. Thus, in most
cases, Central Stations no longer have to purchase
specialized Line Cards or require specific accounts to call
particular phone numbers. Furthermore, virtually all
modern control panels can be programmed to transmit data
in any one of a wide range of formats, making concerns
about the compatibility between the alarm system and the
Central Station equipment a thing of the past.
So how do the multipurpose Line Cards in the Central Station
receiver distinguish between the various Reporting Formats
they may receive? From page B-1 and
Section 1, Getting
Acquainted,
we learned that a
handshake
(
acknowledgement
)
tone is produced by the Central Station Receiver whenever it
answers an incoming call, indicating that it's ready to receive
data. In effect, the
handshake
tone "invites" the communicator
to transmit its message to the Central Station.
Both
PARAMETER 62
and
PARAMETER 07
(see pages
2-59 and 2-14, respectively) allow us to specify which of the
three types of handshakes currently used in the
communication process will be produced when the CP-
220A's Line Card answers the call. If the communicator
recognizes the handshake, it generates the alarm message
in the format that it was programmed to produce. If the
handshake is not recognized, no response will be
forthcoming, and the receiver will produce the next
handshake specified in
PARAMETER 62/PARAMETER 07
– and again wait for a response. Based upon which
handshake was used by the receiver, and the subsequent
message generated by the communicator, each Line Card in
the CP-220A will be able to reconstruct the report and send
it to the display.
All of this is "transparent" to the operator, and with most of
the
non-Contact I.D.
reporting formats that follow, what is
displayed on the CP-220A (and subsequently sent to the
printer and to the Automation System) can be easily
interpreted, no matter which communication protocol is being
used.
Page B-4 Appendix B:
CP-220A Central Station Receiver
Communication Formats
Hook-Up and Installation Manual