How ATMs
Work You’re short on cash, so you walk over to the
automated teller machine (ATM) ,insert your card into the card reader, respond
to the prompts on the screen, and within a minute you walk away with your money
and a receipt. Have you ever wondered about the process that makes your bank
funds available to you at an ATM on the other side of the country ATM
Card vs. Check Card As an alternative to writing checks and
using a credit card, most major banks have teamed up with major credit-card
companies to issue check cards. Check cards are different from
straight ATM cards in a couple of ways. First, check cards are also known as
debit cards because of how they work--instead of getting credit for your
purchase and receiving a monthly bill, like you do with a credit card, a
check/debit card deducts money from your checking or savings account.
Also, while you can only use your ATM card at the ATM machine (and some
grocery stores), you can use a check card at most retailers that accept credit
cards. There are exceptions. Some hotels and rental car services
only accept credit cards because it’s easier, cheaper, and less of a risk to
them than check cards. Those that do accept check cards often put a certain
amount of money in your bank account "on hold" (unavailable to you)-usually the
cost of the room or rental including taxes and other fees, plus a percentage of
the total or a fee to cover possible damages. When you check out of the hotel or
turn in your rental car, the difference between the" hold" amount and what
you’re actually billed .is released back into your account: This is something to
consider when using your debit card to reserve a hotel room or rent a
car. The Way ATMs Work An ATM is simply a data
terminal with two input and four output devices. Like any other data terminal,
the ATM has to connect to, and communicate through, a host processor. The host
processor is analogous to an Internet service provider (ISP) in that it is the
gateway through which all the various ATM networks become available to the
cardholder (the person wanting the cash). Most host processors
can support either leased-line or dial-up machines. Leased-line machines connect
directly to the host processor through a four-wire, point-to-point, dedicated
telephone line. Dial-up ATMs connect to the host processor through a normal
phone line using a modem and a toll-free number, or through an Internet service
provider using a local access number dialed by modem.
Leased-line ATMs are preferred for very high-volume locations because of
their thru-put capability, and dial-up ATMs are preferred for retail merchant
locations where cost is a greater factor than thru-put. The initial cost for a
dial-up machine is less than half that for a leased-line machine. The monthly
operating costs for dial-up are only a fraction of the costs for
leased-line. The host processor may be owned by a bank or
financial institution, or it may be owned by an independent service provider.
Bank-owned processors normally support only bank-owned machines, whereas the
independent processors support merchant-owned machines. Sensing
Bills The cash-dispensing mechanism has an electric eye that
counts each bill as it exits the dispenser. The bill count and all of the
information pertaining to a particular transaction is recorded in a journal. The
journal information is printed out periodically and a hard copy is maintained by
the machine owner for two years. Whenever a cardholder has a dispute about a
transaction, he or she can ask for a journal printout showing the transaction,
and then contact the host processor. If no one is available to provide the
journal printout, the cardholder needs to notify the bank or institution that
issued the card and fill out a form that will be faxed to the host processor. It
is the host processor’s responsibility to resolve the dispute.
Besides the electric eye that counts each bill, the cash-dispensing
mechanism also has a sensor that evaluates the thickness of each bill. If two
bills are stuck together, then instead of being dispensed to the cardholder they
are diverted to a reject bin. The same thing happens with a bill that is
excessively worn, torn, or folded. The number of reject bills is
also recorded so that the machine owner can be aware of the quality of bills
that are being loaded into the machine. A high reject rate would indicate a
problem with the bills or with the dispenser mechanism. Settlement
Funds When a cardholder wants to do an ATM transaction, he
or she provides the necessary information by means of the card reader and
keypad. The ATM forwards this information to the host processor, which routes
the transaction request to the cardholder’s bank or the institution that issued
the card. If the cardholder is requesting cash, the host processor causes an
electronic funds transfer to take place from the customer’s bank account to the
host processor’s account. Once the funds are transferred to the host processor’s
bank account, the processor sends an approval code to the ATM authorizing the
machine to dispense the cash. The processor then transfers the .cardholder’s
funds into the merchant’s bank account, usually the next bank business day. In
this way, the merchant is reimbursed for all funds dispensed by the
ATM. ATM Security ATMs keep your personal
identification number (PIN) and other information safe by using encryption(加密)
software such as Triple DES (Data Encryption Standard). But there are lots of
things that you can do to protect your information and your money at an
ATM. Many banks recommend that you select your own PIN. Visa
offers the following PIN tips: Don’t write down your PIN. If you
must write it down, do not store it in your wallet or purse.
Make your PIN a series of letters or numbers that you can easily remember,
but that cannot easily be associated with you personally-such as birth dates,
initials, house numbers or your phone number. Visa also
recommends the following tips for safe ATM usage: Store your ATM
card in your purse or wallet, in an area where it won’t get scratched or
bent. Get your card out before you approach the ATM. You’ll be
more vulnerable to attack if you’re standing in front of the ATM, fumbling
through your wallet for your card. Stand directly in front of
the ATM keypad when typing in your PIN. This prevents anyone waiting to use the
machine from seeing your personal information. After your
transaction, take your receipt, card and money away. Do not stand in front of
the machine and count your money. If you are using a drive-up
ATM, get your vehicle as close to the machine as possible to prevent anyone from
coming up to your window. Also make sure that your doors are locked before you
drive up to the machine. Do not leave your car running while
using a walk-up ATM. Take your keys with you and lock the doors before your
transaction. If someone or something makes you uncomfortable,
cancel your transaction and leave the machine immediately. Follow up with your
bank to make sure the transaction was cancelled and alert the bank to any
suspicious people. For safety reasons, ATM users should seek out
a machine that is located in a well-lighted public place. Federal law requires
that only the last four digits (阿拉伯数字)of the cardholder’s account number be
printed on the transaction receipt so that when a receipt is left at the machine
location, the account number is secure. However, the entry of your four-digit
personal identification number (PIN) on the keypad should still be obscured from
observation, which can be done by positioning your hand and body in such a way
that the PIN entry cannot be recorded by store cameras or store employees. The
cardholder’s PIN is not recorded in the journal, but the account number is. If
you protect your PIN, you protect your account. Be sure not to use birth dates or your phone numbers as your PIN because they ______.