Module protocol 

ECR17 application-message builders — the bytes that go between STX and ETX.

Every field is fixed-width and validated: a value that overflows its field returns Ecr17Error::FieldOverflow so a malformed frame is never produced. Ported from the reference C++ Ecr17Protocol.

payment_type is the single request digit: '0' auto, '1' debit, '2' credit, '3' other (see crate::types::PaymentCardType).

Functions

build_additional_tags

Additional data for GT / tokenization 'U' (variable).

build_card_verification

Card verification 'H' (39 bytes).

build_close_session

Close session 'C' (26 bytes).

build_enable_ecr_print

Enable/disable ECR printing 'E' (11 bytes).

build_extended_payment

Extended payment 'X' (167 bytes).

build_incremental

Incremental pre-auth 'i' (176 bytes).

build_payment

Payment 'P' (167 bytes).

build_pre_auth

Pre-auth 'p' (167 bytes).

build_pre_auth_closure

Pre-auth closure 'c' (176 bytes).

build_reprint

Reprint ticket 'R' (22 bytes).

build_reversal

Reversal 'S' (26 bytes); stan = "000000" reverses the last payment with no STAN check.

build_send_last_result

Send last result 'G' (22 bytes).

build_status

Status 's' (10 bytes; lowercase code per spec).

build_totals

Totals 'T' (26 bytes).

build_vas

VAS 'K' (variable, length-prefixed XML, max 1024 bytes).

format_tokenization_tag

Formats the TAG 5 content for tokenization (Intesa-style mapping): "0COF0TRK<contract>|0FNZ03" (unscheduled/one-click) or "0REC0TRK<contract>|0FNZ03" (recurring). recurring selects 0REC vs 0COF.