B5 ATM
Needs: Supporter
The ATM and its host, ATM transactions, dispensing and partial dispense, ATM keys, card retention and balancing.
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What this module covers
You will be able to
- Describe the ATM, its devices and the ATM–host leg
- Follow withdrawal, balance, transfer, deposit and PIN change
- Handle dispense failures and partial dispense (field 95)
- Load ATM keys
- Explain card retention, surcharge and balancing
The lesson
- Why it matters
- The concept
- Transactions
- Dispensing
- Keys
- Operations
- Common mistakes
- What to test
In the module
- The lesson, with diagrams, common mistakes and what to test
- A worked example you can change: Dispensing, and a partial dispense
- Practice: 4 kinds of generated exercise, each with a step-by-step solution
- A quiz of 9 questions
Key terms
- ATM (Automated teller machine)
- A self-service terminal for withdrawals, balance inquiries, transfers and often deposits, run by an ATM host.
- ATM host
- The system that drives the ATMs: it sends screens and state tables, receives transaction requests, authorises through the networks and tells the ATM what to dispense.
- Card retention (Card capture)
- The ATM keeping the card, on the issuer's instruction (pick-up response codes) or because the cardholder did not take it.
- Cash balancing (Reconciliation)
- Comparing the notes counted out of the cassettes with the host's totals of dispensed amounts.
- Cassette
- A container of notes of one denomination in the ATM dispenser. The host knows each cassette's denomination and count.
- Dispense
- The ATM counting out and presenting the notes after the host's approval.
- Electronic journal
- The ATM's log of every transaction and device event, used to settle disputes and balance the machine. It is masked like any log.
- Note mix
- How many notes of each denomination the ATM dispenses for an amount, chosen from what the cassettes hold.
- On-us
- A transaction where the acquirer is also the issuer, such as your own bank's ATM. Off-us transactions go through a network.
- Partial dispense
- When the ATM pays out less than approved because of a jam or empty cassette. The host must send a partial reversal with the dispensed amount in field 95.
- Retract
- The ATM pulling back notes the cardholder did not take. The amount is reported to the host, which may reverse it.
- Solicited status
- The ATM's report back to the host after carrying out a reply, such as 'dispensed' or 'device fault'. Unsolicited status reports events nobody asked about.
- State table
- The ATM's program, downloaded from the host: each state shows a screen, waits for an input and moves to the next state.
- Supervisor mode
- The ATM mode used by staff to replenish cassettes, print totals and clear faults; the ATM is out of service meanwhile.
- Surcharge (ATM access fee)
- A fee the ATM owner adds for a cardholder of another bank, disclosed on screen and carried in field 28.
- Transaction reply (ATM reply)
- The host's answer to the ATM: the next state, the screen, the notes to dispense and what to print.
- Transaction request (ATM request)
- The ATM's message to its host once the cardholder has chosen a transaction: card data, PIN block, the keys pressed and the amount.
The lesson, worked example, practice and quiz open with a supporter pass, which you can try free for 7 days.