parking_solution/wiki/entities/rongta-printer.md

type, tags, sources, updated

type	tags	sources	updated
entity	parking hardware printer device		2026-09-09

Rongta 80mm thermal printer

The chosen ticket/receipt printer: a Rongta RP-series 80mm network thermal printer (and the many ESC/POS-compatible OEM clones that share its firmware). Driver rongta in packages/devices implements device-adapter-pattern.

Transport & protocol

• ESC/POS over a raw TCP socket on port 9100 (the JetDirect/RAW convention). The driver opens the socket, writes the ESC/POS byte stream, and closes GRACEFULLY.

  Graceful close — fixed 2026-06-19. sendRaw() previously did write(payload) then destroy() on the write callback. But a Socket.write() callback fires when bytes reach the local kernel buffer, NOT when the peer has read them — so destroy() could send a TCP RST that truncates the job mid-stream, leaving the printer a desynced ESC/POS stream (raster garbage). Now it end(payload) (write + FIN, a clean half-close) and resolves on the socket's close event — which only fires after the printer has drained the bytes. A timeout after the write completed is treated as success (some printers never send their own FIN), so a delivered job is never spuriously failed. A latent bug found while diagnosing the KP-300H garbage; it was NOT the cause of that (see overflow gotcha below) but is a real truncation risk on its own.

• No authentication on the print socket — anyone who can reach port 9100 can print. Like every other field device it must sit on the isolated device VLAN (network-isolation). There is no real HTTP/control boundary on the device (same posture as dingtian-relay).
• Health check is a TCP connect probe to 9100. The print socket exposes no status protocol we rely on; the print itself is the real reachability test (failover attempts the print).
• Live status comes from the device's own web page http://<host>/prn_stat.htm (port 80), which decodes Cover Open / Cutter Error / Paper End / Paper Near End / Off-Line into Yes/No. We scrape that rather than hand-decode DLE EOT — this clone's DLE EOT reply bytes do not match the canonical ESC/POS bit layout (verified on hardware), so trusting the device's own decode avoids a false-healthy. Implemented as readStatus(); see printer-status-monitoring.
• USB transport (added 2026-06-24). The same driver can instead drive a printer over a local USB usblp char device (/dev/usb/lp0) — config.transport (tcp-ip | usb) picks the wire behind one render layer (the ESC/POS bytes are identical). The status web page is a network feature, so a USB Rongta degrades to reachability-only monitoring (open-the-node probe, no paper/cover verdict — the same honesty floor as the Cashino). Driving USB depends on the appliance image (usblp bound + a udev write-access rule) — a provisioning step, open-questions #14. Full rationale in printer-usb-transport.

Deployment (this site)

• First printer verified reachable at 10.0.10.6:9100 from the host (TCP connect OK, 2026-06-14).
• Two printers configured (as of 2026-06-18), by role — see printer-roles-failover:
  • entry-dispenser — 10.0.10.9, outside at the lane; the driver takes the entry ticket. This unit is a Cashino, not a Rongta: it prints the same ESC/POS stream but serves no /prn_stat.htm status page, so it runs on the generic ESC/POS driver (id escpos — renamed from cashino 2026-07-06, migration 0023; reachability PING only, no paper/cover status) — see printer-status-monitoring, printer-usb-transport.
  • booth-receipt — 10.0.10.10, inside the booth; receipts, AND the backup that prints the entry ticket if the outside dispenser is offline. This unit is a Rongta (rongta driver, full status-page monitoring).
  • Not a Rongta, its own driver since 2026-09-09: the K200L (Xprinter/ICS XP-K200L family; LAN board calls itself "POS-80") — the park-buzi unit and the lab's 10.0.10.11 unit. Same five-row status table under /prt_status.htm (not /prn_stat.htm), served without HTTP headers, so it has the k200l driver with a raw-socket fetch. See k200l-printer.

Ticket rendering

printTicket(TicketData) builds ESC/POS: ESC @ init, centered/bold/double-size header, lane, ticket id, issued-at, feed + partial cut (GS V B). CP437/ASCII subset. The entry ticket encodes the id as a 1D Code128 barcode (GS k).

printSubscriptionCard(SubscriptionCardData) (added 2026-06-18) renders a 2D QR of the subscription code via ESC/POS GS ( k (model 2, EC level M) — firmware-rendered, no bitmap dependency — plus the code as text + holder/validity. Used for the auto-printed + reprintable subscription card. (Verified: the GS ( k store/print byte sequences + the embedded code appear on the wire against a TCP capture.)

printReceipt(ReceiptData) (added 2026-06-18) — the payment receipt / exit voucher (booth-exit-flow). Same ESC/POS preamble; figures + amount, optional Code128 + grace.

CP852 codepage — two gotchas found on a real misprint (2026-06-18)

The driver selects CP852 (Latin-2) via ESC t 18 and maps the Albanian letters to their CP852 bytes. A printed voucher surfaced two encoding bugs, both now fixed in printer-escpos.ts:

• Uppercase Ë was mapped to 0xEB — wrong. In CP852 0xEB is ű; the correct byte for Ë (U+00CB) is 0xD3. The title BILETË DALJE / FATURË PAGESE printed garbled until fixed. (Lowercase ë = 0x89 was always correct.) Anyone extending the CP852 map must verify bytes against the actual Unicode.org CP852.TXT, not guess.
• Intl.NumberFormat injects a NO-BREAK SPACE. Formatting ALL money yields "1000 Lekë" (separator = U+00A0, sometimes U+202F narrow NBSP) — neither is in CP852, so it printed as 1000?Lekë. line() now normalises U+00A0/U+202F → a plain space before encoding. Any Intl-formatted value on a ticket is affected, not just money.

KP-300H barcode overflow — only the Cashino garbled (2026-06-19)

The Cashino entry dispenser printed raster garbage on entry tickets while the booth Rongta printed the same byte stream cleanly. Root cause was barcode line-overflow, not corruption: a 13-digit Code128 at module width 3 (~534 dots) overran the KP-300H's 72mm = 512-dot line; the Rongta's 80mm (576) had room. Plain-text-only prints were clean, isolating it to the GS k barcode. Fix: shorten the ticket id 13→11 digits (~468 dots — fits 72mm) — see ticket-encoding for the geometry. Module width must stay 3: a test at width 2 scanned but returned truncated values. General rule: size firmware barcodes/QRs to the narrowest deployed printer's usable dot width.

Human dates on printed slips — Albanian (2026-06-19)

stamp() now formats timestamps as 19 Qershor 2026 10:48:25 (Albanian month, 24h with seconds) instead of YYYY-MM-DD HH:MM. Month names are a hardcoded SQ_MONTHS table (the appliance browser's ICU lacks Albanian locale data — see i18n). stamp is exported as formatStampSq so the shift shift shares the one Albanian date format. Applies to ticket issue time, receipt entry/paid rows, and subscription validity dates (date-only). Consistent with the "i18n" rule.

Status

Driver written and compiles; entry-ticket layout is a first pass; live status monitoring is implemented and verified (printer-status-monitoring). The receipt/exit layout and the cash-drawer kick (ESC/POS ESC p) are not yet implemented — they arrive with the exit/payment flow. Replaces the generic "Epson TM / Citizen" booth-printer line in bom.