manual

MANAGEMENT FUNCTIONS
201
Once the Heartbeat Message call feature is enabled at the terminal, an in-
ternal timer will be initialized to the number of minutes set in the DELAY
PERIOD parameter at system power-up and after a reset. This timer is
restarted each time a call is made to the host. A call to the host is defined as
any transaction, including financial, balancing and configuration that actually
communicates with the host to the point that the Terminal ID is recognized.
A customer transaction that is declined will reset the timer, while a call that
fails because the host phone number was busy would not.
It is important to remember that as long as transactions are being done on
the terminal on a regular basis, Heartbeat Message calls will not be made.
The sole purpose of these calls is to let the host know that the terminal is
OK when it is NOT performing regular transactions.
Because the primary purpose of the Heartbeat Message call is to let the host
know everything is all right, a Heartbeat Message call that DOES NOT
succeed for any reason is not retried. If the call does fail, the interval timer
will be reset and the terminal will remain in service.
While the concept of the Heartbeat Message call is simple, interpreting the
absence of an expected call must be explained. Listed below are reasons
why Heartbeat Message calls will not be received at the host either when
expected or at all.
Feature Not Turned On
Obviously, if the feature in not enabled, no Heartbeat Message calls will
be made.
Terminal is Doing Transactions
If the terminal does at least one regular customer transaction or balancing
transaction before the interval timer, no Heartbeat Message call will be
made.
Terminal is in Management Function Mode
Heartbeat Message calls are suspended while the terminal is in the Manage-
ment mode, although the interval timer continues to run. If the timer expires
while the terminal is in this mode, the call will be delayed until the terminal
returns to the normal service mode.
Terminal is Out of Service
When the terminal goes out of service, one Heartbeat Message call is made.
After that call, all further calls are suspended until it is returned to normal
service.