FN Errors and Reading the Archive of a Closed Fiscal Drive

"FN Communication Error" can mean a loose ribbon cable, or it could mean the drive is in its final weeks. The difference is fundamental: in the first case, a ten-minute diagnostic helps; in the second, you need to prepare for an unscheduled replacement and, in the worst-case scenario, saving the archive of a dying FN. We break down how to distinguish one from the other and what to do if the storage device didn't survive the closure.

1. Code Family 210–235: Communication Failure or Dying FN#

The exact wording and numbering depend on the fiscal register manufacturer (ATOL, SHTRIH-M, Pirit, Mercury, etc.) and firmware version — check the code against your model's documentation. However, the general principle is the same for most manufacturers: some codes describe a communication or exchange protocol failure (fixed by on-site diagnostics), while others indicate an actual failure of the storage device itself.

Rule of thumb: codes from the "exchange/protocol" family are almost always resolved on-site without replacing the FN; codes indicating a hardware failure require manufacturer expertise and readiness for section 3.

2. "FN Communication Error" Pops Up Periodically — Troubleshooting#

Check in the following order:

1. FN slot connection — the drive is inserted tightly, the ribbon cable/adapter is not bent and does not disconnect during vibration.
2. Contacts — oxidation or dust on the connector contacts (open the case carefully if it is not sealed by a service center).
3. Power supply — voltage drop, low-quality power supply unit, swollen battery on standalone models such as 91F/92F — a frequent cause of intermittent failures (see power diagnostics in the article "ATOL Errors").
4. Firmware — if the error appeared immediately after an update, check the compatibility of the firmware version with the FN model and manufacture date.
5. Persistent error — if the error occurs consistently and does not depend on intervention, it is likely no longer a "communication failure", but hardware degradation of the storage unit: proceed to Section 3 and keep a backup FN on hand in advance (see also "Backup POS").

3. FN died before closing the archive: what to save and how to report#

First of all: documents already transmitted to the OFD before the failure are not lost — their copy remains with the operator. At risk are only those that were queued for sending.

1. Record the breakdown with a certificate/act (service center/CTO) specifying the date and nature of the failure.
2. Send the FN to the manufacturer for examination — their conclusion is required: whether it confirms the memory controller is functional and the archive can be read.
3. Submit an application to unregister the POS in the FNS personal account due to the failure, attaching the act — if the standard FN closure report cannot be generated.
4. Install a new FN and perform a full registration of the POS from scratch, see “Registering a POS with the FNS”.
5. If the manufacturer confirms the possibility of reading — the restored fiscal data is transferred to the FNS, estimated deadline is 60 days from the date of submitting the re-registration application (the same procedure as in the article “Correction receipt in case of POS breakdown”).
6. Transactions that did not get into the FN at all because the POS was physically not working are covered by correction receipts in the usual manner — described in that same section.

4. Need to retrieve a receipt from six months ago — where to look#

Start with the fiscal document attribute (FPD) — it is printed on the receipt on a separate line and allows for a more precise search than by time or amount (see also "Receipts not sending to OFD", section 7). If the OFD has changed since then, the previous operator's archive is usually available for a limited time after contract termination; check this separately.

5. How to read a closed FN: utilities and USB adapter#

A regular POS user cannot "just open" the FN archive via software — a special tool is required:

• FN manufacturer utility — specific to each manufacturer, usually provided upon request via support; it exports fiscal documents in a structured format rather than printing all receipts sequentially.
• USB adapter for FN — a device that connects the removed closed drive directly to a PC, bypassing the POS, for subsequent reading by the utility.

When it is actually needed: to retrieve old documents that are absent from both the OFD and your sales log; to conduct an expert evaluation of a damaged FN (section 3); to prepare data upon request from the tax authority during an audit. In practice, this procedure is almost always performed by a service center or the manufacturer itself — not all FN models support reading after controller damage.

6. Lost Old FN (Mandatory 5-Year Storage) — What Are the Risks#

The obligation to store decommissioned FNs for five years is established and detailed in the article "FN Replacement" (Section 5). If the drive is lost or destroyed ahead of time:

• documents confirmed by the OFD do not physically disappear — their copy remains with the operator; the risk applies only to unverified settlements for which the drive was the sole source;
• during an audit, the absence of an FN that was required to be stored may in itself be considered a violation of storage rules — check with your accountant for the exact scope of liability.

Maintain an inventory list of decommissioned FNs with dates and certificates — losing track of the storage process itself is just as easy as losing the drive.

7. Swapping an FN Between Cash Registers of the Same Legal Entity — Why It Is Not Allowed#

An FN is fiscalized — irreversibly linked to the cash register's registration number and TIN — upon its initial activation (see Section 3 of the article "KKT Registration with the FNS"). Even within the same legal entity, you cannot remove an active fiscal drive from one cash register and install it into another: the cash register will physically not allow operating an FN fiscalized under a different number, and a mismatch between the serial numbers of the cash register and the FN will surface during reporting reconciliation.

The only legal way to transfer is to close the archive, unregister the original cash register, and then install a new FN for the other location. A used drive, even if it has not reached the end of its service life, is suitable only for reading the archive (Section 5).

8. Example#

Restaurant, FFD 1.2. The POS periodically started displaying an "FN exchange error", which cleared on its own after a reboot. A month later, the error turned into code 234 and no longer disappeared. The service center extracted the FN, and the manufacturer confirmed partial readability of the archive. The restaurant filed an application to deregister the POS due to equipment breakdown, installed a new FN, and completed registration anew; the recovered documents were submitted to the FNS within 60 days, while transactions made without the FN during two hours of downtime were covered by correction receipts.

9. How to do this in Cenaly#

• The electronic log POS → Receipts stores a copy of every receipt independently of the FN and OFD — if you need to pull up a receipt from six months ago, start here.
• The Equipment section shows the status of the fiscal register connected via Cenaly Hardware Bridge; recurring communication failures with the FN are visible in live activity as separate events — the problem is visible at the "exchange failure" stage, before the drive actually fails.
• Transactions during diagnostics or FN replacement are registered with a correction receipt in the same place — see the guide to correction receipts.
• After re-registering the POS with a new FN, the cloud portion of Cenaly — menu, settings, history — does not require re-configuration, only a new linking via Hardware Bridge.

10. Frequently Asked Questions#

Are Error 235 and Error 234 the same thing? No. 235 is a memory overflow due to documents not being sent to the OFD, resolved by establishing a connection and planned replacement; 234 is a hardware drive failure requiring expert examination.

What is an FPD and where to find it on a receipt? Fiscal Document Attribute — printed on the receipt as a separate line, the most reliable identifier for searching in the OFD account or FNS portal.

What if the manufacturer could not read the archive of a failed FN? A certificate on the impossibility of reading data is drawn up and attached to the documents submitted to the FNS; transactions for the period are restored based on available data (POS journal, receipt copies) — this is a last resort, consult an accountant.

Will a periodic "FN exchange error" resolve itself after restarting the POS terminal? It might temporarily disappear, but if it recurs regularly, it is a sign of physical degradation rather than a one-time glitch; do not delay diagnostics from Section 2.

Related articles: backup POS, relocation, and updating company details · fiscal storage replacement · registering a POS terminal with the FNS · receipts are not sent to OFD · smart terminals: subscriptions and used devices

This material is for informational purposes only and does not replace consultation with a service center, FN manufacturer, or accountant. Primary sources: Federal Law No. 54-FZ "On the Use of Cash Registers", FNS guidelines on operating cash registers and FN (kkt-online.nalog.ru), operational documentation, and statements from fiscal storage manufacturers.