Briefly, an ATM is a data terminal with two input devices and four output devices. Like any other data terminal, an ATM must connect to and communicate with a main processor. The main processor acts like an Internet Service provider (ISP) and is the point of entry through which cardholders (those who want to withdraw cash) can access various networks of ATMs.
Most main processors support dedicated or dial-up ATMs. Dedicated line connected machines are directly connected to the main processor via a four-line dedicated point-to-point telephone line. Dial-up ATMs connect to the main processor through a regular telephone line using a modem and a toll-free number, or through an Internet service provider using a local access number dialed by a modulation mediator.
Because of the high throughput capacity of line ATMs, they are usually used in high-traffic areas, while dial-up ATMs are used in high-traffic areas, where cost is a more important consideration because the initial cost of a dial-up machine is less than half that of a line machine. The monthly running cost of a dial-up machine is a fraction of that of a dedicated machine.
The main processor may be owned by a bank or financial institution, or it may belong to an independent service provider. Bank-owned processors typically support only bank teller machines, while standalone processors support commercial teller machines.
You may be one of millions of automated teller machine users. As we know, each ATM has two input devices:
Card Reader - A card reader can access information stored in the magnetic stripe on the back of an ATM card, debit card, or credit card. The master processor uses this information to route the transaction to the cardholder's bank.
Keypad - The card holder uses keypad input to tell the bank what kind of transaction is required (withdrawal, inquiry, etc.) and the amount of the transaction. In addition, banks require cardholders to enter a personal password (PIN) for authentication. Us federal law requires that PIN data blocks be sent to the main processor in encrypted form.
An automated teller machine has four output devices:
Speakers - Speakers provide sound feedback when the cardholder presses the keyboard.
Display - The display is provided to guide the cardholder through each step of the transaction process. Automated teller machines (ATMs) connected to dedicated lines usually use monochrome or color CRT displays. Dial-up ATMs usually use monochrome or color LCD monitors.
Voucher Printer - Voucher printer provides cardholders with paper transaction credentials.
Banknote outlet - The core of ATM is banknote box and banknote outlet module. The entire bottom of most small ATMs is a box for holding cash.
An automated teller machine has an electronic eye that counts each bill as it pours it out. The bill amount and all information regarding each particular transaction is recorded in the journal. The machine owner regularly prints the journal information and maintains a hard copy of the transaction information for two years during which the transaction takes place. Whenever a cardholder has questions about a transaction, he can request a printed journal of the transaction and then contact the main processor. If no owner can be found who can provide a printed record of the journal, the cardholder needs to notify the bank or card issuer and fill out the relevant form and fax it to the main processor, which resolves the transaction dispute.
In addition to counting each bill with an electronic eye, the ATM also has a sensor that estimates the thickness of the bill. If two bills are stuck together, they are thrown into the demonetization bin and not provided to the withdrawer. This is also true for very old and folded bills.
