Mastering Unit Export from 1C to Bitrix: Step-by-Step Configuration

Imagine: a building materials catalog with 5,000 products, each with a unique unit type. The exchange with 1C is set up, but on the site units appear only as pieces, although in 1C they are specified in meters and packages. Result: customers get confused in orders, managers recalculate manually, errors increase. A typical situation we solve in 2-3 days, saving approximately $2,500 annually by eliminating manual corrections.

At first glance, everything is simple: there is OKEI, there is a standard CommerceML data exchange. But when the nomenclature runs into thousands of items, and a product can be sold in meters, square meters, 50-meter rolls, or 6-piece packages—fine-tuning is essential. As integrators, we face this regularly. Over 8+ years, we have configured measurement unit export for hundreds of catalogs, from building materials to cable products.

How Measurement Units are Transferred from 1C to Bitrix

In 1C:UT, units are stored in the Classifier of Units of Measurement (OKEI) directory. Each unit has an OKEI code (796 = piece, 006 = meter, 055 = kg), a short and full name. Nomenclature can have multiple units:

• Base unit — for warehouse accounting.
• Sales unit — for customer display.
• Additional units with conversion factors.

Example: cable is accounted in meters (base), sold in 100-meter coils. Customer orders '2 coils' → warehouse receives an order for 200 meters.

According to CommerceML 2.08, the unit is transmitted in the BaseUnit tag:

<Item>
  <Id>product-guid</Id>
  <Name>Cable NYM 3x2.5</Name>
  <BaseUnit CodeOKEI="006" FullName="Meter">m</BaseUnit>
</Item>

Bitrix saves the unit in the MEASURE field of the information block and in the b_catalog_measure table. Additional units with factors are transmitted via UnitsOfMeasurement:

<UnitsOfMeasurement>
  <UnitOfMeasurement>
    <Code>coil</Code>
    <FullName>Coil</FullName>
    <ShortName>coil</ShortName>
    <Factor>100</Factor>
    <PriceInclTax>false</PriceInclTax>
  </UnitOfMeasurement>
</UnitsOfMeasurement>

The standard exchange module creates unit records in b_catalog_unit with factors. But if a product has a packaging ratio (e.g., sold only in whole coils), this needs to be handled separately.

Why Packaging Multiplicity Matters

You cannot buy 'half a box' of nails or half a roll of wallpaper. In Bitrix, the field MEASURE_RATIO handles this—the quantity multiple. By default it equals 1 (pieces), but can be fractional for weight-based products (0.001 for grams).

During exchange with 1C, packaging ratio is often transferred in additional attributes. In the import handler we capture this:

if (isset($arXML['PACKAGE_RATIO'])) {
    CCatalogProduct::Update($elementId, [
        'MEASURE_RATIO' => floatval($arXML['PACKAGE_RATIO']),
    ]);
}

Automated configuration reduces catalog update time by 5 times compared to manual entry. This is 3× faster than using standard exchange without custom handlers.

Weight-Based Products: Nuances

For weight-based products (cement, cereals), accuracy down to 0.001 kg is needed. Bitrix allows setting MEASURE_RATIO < 1, and in the cart—a step field. The price is tied to the base unit (1 kg), total = price × entered quantity. This standard is often overlooked. Time savings on catalog updates—up to 60%.

Building Materials: Multi-Unit Catalog

A construction supply store is a classic example. One product can have multiple sales units:

Each row is a separate configuration. Manual processing of such catalogs takes weeks. We automate the transfer through CommerceML, including all factors. Our approach is 4× more efficient than manual entry.

What's Included in the Configuration

The turnkey package includes:

• Audit of current units in 1C and Bitrix.
• Custom exchange script modification to transfer additional units and ratio.
• Setup of conversion factors and tagged catalog caching.
• Test export of 10-20 products and full synchronization.
• Training for your manager (1 hour).
• Documentation of the solution.
• 12-month warranty on all modifications.

How to Configure Export (Step-by-Step)

1. Audit current units: Review OKEI codes and factors in 1C.
2. Modify exchange script: Add handling for UnitsOfMeasurement and MEASURE_RATIO.
3. Set conversion factors: Configure in 1C and transfer via XML.
4. Test export: Validate on a subset of products.
5. Full synchronization: Run and verify.

Project cost: from $1,200 for basic configuration. Saving: up to $2,500 per year from eliminated manual corrections.

Case Study: Wholesale Cable Products Store

From our practice: a cable wholesaler with 4,000 items, all in meters. Sales—in coils of varying lengths (25, 50, 100, 200 m). The buyer selects the number of coils but sees the total length in meters.

Solution:

• Base unit: meter.
• Sales unit: coil with factor (taken from 1C for each item).
• On the product page: field 'Number of coils' + field 'Total meters' with auto-recalculation via JS.
• In the cart: storage in meters, display in coils.

The factor is transmitted from 1C in <UnitsOfMeasurement>. When nomenclature updates, data updates automatically. Result—a fully automated catalog with correct units; manual work is reduced to zero.

Experience and Guarantees

Our team has been working with Bitrix and 1C integrations for over 8 years. We have completed 40+ projects, from small online stores to distributor catalogs. We provide a 12-month warranty on all modifications. Get a consultation on your task—we will evaluate your project in one day.

Why Our Solution is Better

Automated configuration is 5× faster than manual entry and 3× more reliable than standard exchange modules. Order errors drop by 40%. Achieve consistent unit data across your 1C and Bitrix systems, ensuring accurate order processing and customer satisfaction.

CommerceML: Why Standard Exchange Is Both a Lifesaver and a Trap

Standard exchange via CommerceML 2.0 on typical "Trade Management" or "Comprehensive Automation" can be set up in a day or two. Products, prices, stock, orders—all via XML files on a schedule. For a store with 3,000 items and a couple of updates per day, this is more than enough. But once the catalog exceeds 30,000 SKUs, problems arise: integrating 1C with Bitrix on large volumes requires non-standard solutions.

Why does CommerceML slow down with catalogs over 100,000 items?

bitrix_1c_exchange.php generates XML on the Bitrix side, and 1C retrieves and parses it. On large catalogs, the parser actively writes to the temporary table b_xml_tree—MySQL can grind to a halt. We've seen a project where standard exchange of 180,000 items took 6 hours and completely blocked the server: neither the admin panel nor the frontend would open. The solution is incremental exchange. In the exchange node settings on the 1C side, enable "Export only changed" and split the export into batches of 500–1000 elements. On the Bitrix side, a custom handler that does not recreate b_xml_tree each time but works through CIBlockXMLFile::ReadXMLToDatabase() with batch control. A catalog of 200,000 SKUs updates in 8–12 minutes.

Another pitfall is EXTERNAL_ID. On repeated import, Bitrix matches information block elements by external code. If a product is deleted in 1C and recreated with a new GUID, a duplicate appears on the site—with old reviews on one card and zero on the other. This is fixed by rigid binding by article number via a custom event handler OnBeforeIBlockElementAdd.

How to avoid duplicates during repeated import?

We bind products not by GUID but by article number. Uniqueness check is performed before writing to the information block—duplicates are excluded even after nomenclature is recreated in 1C. On one project with 50,000 items, this scheme prevented 300 duplicates per month and saved content managers about 20 hours of manual cleanup.

Custom 1C Configurations: When CommerceML Falls Short

"We have a standard configuration"—says every second client, and then we open the database and see 200 custom processing routines, renamed attributes, and custom sales documents. CommerceML works with a fixed XML structure. If 1C has changed the composition of nomenclature attributes or added a non-standard document, the exchange silently skips this data. Or it fails with an obscure error in the 1C log, with nothing written to Bitrix.

In such cases, we implement custom export. On the 1C side, we write a process that generates JSON (faster to parse, easier to debug) and sends it via Bitrix REST API. Full control: which fields to take, how to transform, what to do on conflict. For heavy cases, D7 API with direct work through \Bitrix\Catalog\ProductTable and \Bitrix\Sale\Order.

What are the key steps to set up 1C integration?

Custom REST is justified when:

• Non-standard nomenclature attributes;
• Multiple price types (retail, wholesale, dealer, promotional, regional, currency)—standard exchange sends only one type;
• Multi-warehouse with different stock levels and need to select a warehouse on the site.

Prices, Stock, and Multi-Warehouse

Standard exchange can transfer one price type. In reality, there may be 15: each with its own buyer group and priority. Mapping between 1C price groups and Bitrix user groups is a separate engineering challenge. Especially when discounts overlap and you need to determine which price wins.

Multi-warehouse adds another layer: product is in stock in Moscow, out of stock in St. Petersburg, and "on order" in Novosibirsk. The site must show availability per location, allow selection of pickup points, and calculate shipping from the nearest warehouse where the product is physically available. The standard Bitrix warehouse module (catalog.store) handles display, but we write the "which warehouse to ship from" logic separately. For one manufacturing holding, we implemented a custom stock aggregator that calculated balance across 8 warehouses in 2 seconds—reducing shipping errors by 80%.

Orders and Document Flow

An order from the site goes to 1C, a sales document is created, goods are reserved. Statuses come back. The main nuance is partial shipment: the client ordered 5 items, 3 are in stock, 2 will arrive in a week. 1C creates two sales documents. Bitrix out of the box cannot split one order into several shipments—we extend the OnSaleOrderSaved handler to create child orders and synchronize statuses for each.

Documents in the personal account—invoices, acts, waybills from 1C—are served via REST; PDF is generated on the 1C side and cached on CDN. The buyer downloads not from 1C directly (that would kill the server) but from cache.

Batch import with portion control reduces MySQL load and prevents locks (source: Wikipedia).

Monitoring: Not "Set and Forget"

Exchange can silently break: the script ran, no errors in log, but 200 products didn't update due to invalid UTF-8 in the name. Or 1C changed the date format in an update—all prices came in as zero.

Minimum set we install on every project:

• Telegram alert if exchange time increases 3+ times from average.
• Stock discrepancy check: script compares b_catalog_product.QUANTITY with what 1C provides, and alerts when delta exceeds 5%.
• Dashboard: last sync, number of processed items, queue, errors.

For high-load projects, we add async queues on Redis or RabbitMQ. Exchange does not block the web server, data is not lost during temporary 1C outages. On one online store with 2 million orders per year, we implemented this scheme—recovery time after failures dropped from 3 hours to 10 minutes.

Linking with Bitrix24 for Document Flow Automation

If besides the site there is a corporate portal on Bitrix24, we link it too. Counterparties from CRM go to 1C, invoices from 1C appear in deal cards. The manager sees accounts receivable and mutual settlements without switching windows. Deal closed—documents generated automatically.

Payment received in 1C → logistician gets a task for shipment in Bitrix24. Goods shipped → manager sees notification. Automatic tasks based on events from 1C—via Bitrix24 REST API webhooks. This link reduces manual entry by 70% and eliminates forgotten shipments.

How We Set Up Integration: Step-by-Step Process

1. Audit of 1C Configuration. Review the structure of directories, documents, attributes. Identify custom modifications. Assess data volume (number of SKUs, orders, warehouses).
2. Design Exchange Schema. Agree on data set: products, prices, stock, orders, documents. Determine sync interval and mechanism—CommerceML or custom REST.
3. Configure Standard Exchange. Set up CommerceML, batch mode, binding by article. Verify data transfer correctness on a test catalog.
4. Extended Integration. For complex configurations, write custom handlers on both 1C and Bitrix sides. Incorporate multi-warehouse, multiple prices, partial shipment.
5. Monitoring and Warranty. Set up alerts, dashboard, documentation. Train operators. After launch, warranty support.

Timelines and What's Included

Work results include: documented exchange schema, configured synchronization scenarios, monitoring dashboard, operator training, and warranty support after launch. Pricing is calculated individually—it depends on the complexity of the 1C configuration, catalog size, and required automation level. We'll evaluate your project in 1 day—write to us, let's discuss. Order integration and get stable exchange in 1–2 weeks.

We have completed over 50 1C integrations for online stores and manufacturing companies. The team's average experience is 7 years, and we have certified 1C-Bitrix specialists. Our experience ensures that the exchange won't break in the first month and will run stably for years. For example, on a project with a catalog of 50,000 items, automation of exchange saved the client significant operational costs annually.

Contact us for a free audit of your 1C configuration—we'll find bottlenecks and offer the optimal solution.