Identifying a Legacy Automation Part From Its Marking and a

Identifying a Legacy Automation Part From Its Marking and a Photo

A bench technician in Yekaterinburg has a 2008 control cabinet open on the floor. The photoelectric sensor on the conveyor end-cap is unmarked; the original label has worn off where it met a coolant leak. One photograph of the device and one of the wiring are the entire input. From those two images the right MPN for an Omron E3Z-family sensor, the right follow-on family, and a per-line condition quotation can come back inside one business day — provided the photograph and the marking tell the desk what they actually carry. The desk receives several requests like this every week from buyers in Moscow, Novosibirsk, Almaty, and across the CIS.

What the marking on an Omron sensor actually carries

A factory-fresh Omron E3Z-series photoelectric switch carries the model string in laser-etched or pad-printed characters on the housing side, the lot code on the bottom, and the connector pin-out on the data sheet that accompanied the device when it left the factory. The model string alone — for example E3ZM-T81 2M, score 89.26 in our catalog — tells the desk the family, the body style, the output configuration, the cable length, and the sensing range. The suffix matters: T81 distinguishes a through-beam receiver from a diffuse-reflective emitter with shorter range; the 2M distinguishes the 2-metre cable variant from the M8 connector variant in the same body.

For proximity sensors the marking usually starts with the family code, for example E2C-X1R5AH (score 89.18). The first letter block identifies the sensing principle (E2 = inductive proximity in the Omron family). The numeric block that follows identifies the sensing distance, the housing diameter, and the output stage. The trailing suffix identifies the cable length, the connector type, and the polarity of the NPN/PNP output. Two sensors in the same physical housing carry different model strings because the output configuration differs; a photograph that captures only the front face and not the label side leaves that information hidden, and the model string has to be guessed.

A marking is also time-sensitive. Manufacturers revise model strings across production runs. The marking on a sensor built in 2009 differs from the marking on the same nominal sensor built in 2014 because of a body redesign, a connector supplier change, or a regional certification update. The Omron E3S-CD12 (score 89.18) is a specific case: the model string is stable, but the lot code suffix identifies the production lot, and the production lot determines which firmware revision, which connector overmould, and which data-sheet revision applies. A photograph of the underside of the housing — where the lot code lives — closes that gap.

What a photograph actually carries — and what it does not

A photograph carries the silhouette of the device, the colour of the housing, the connector type, the cable colour code, the label if it is still legible, the wiring of any visible terminals, and the scale of the device against a reference object (a coin, a finger, a ruler). It does not carry the inside of the housing, the firmware revision burned into a microcontroller that can only be read over the programming port, the exact value of a trimmer inside the device, the factory calibration certificate, or the production-lot trace that a marking carries when it is still on the housing.

For a photoelectric sensor, a single photograph at the right angle is usually enough. The connector pin-out, the housing silhouette, the indicator LED colour, and the cable colour code give the desk enough to identify the family. For a PLC module, one photograph is rarely enough. The label side, the front-panel DIP switch bank, the module side without the door, and a second photograph showing the installed environment — what sits in the slot to the left, what sits in the slot to the right — all matter. A PLC module looks similar to other PLC modules in the same family because that is what the manufacturer designed it to do. The photograph has to capture the differentiating features.

The two photographs that fail most often are the photographs that crop the label, and the photographs that capture the device at a wide angle so that the connector, the indicator LEDs, and the cable colour are too small to read. A request that arrives with a single crop-tight photograph of a damaged front panel tells the desk that the part is damaged, which is information, but not the information the procurement function needs.

What to send in the first message when the marking is still readable

When the marking is still readable, the work is straightforward. Send the model string verbatim from the label. Add a second line with the lot code if it is visible. Add a third line with the connector type if the connector is visible. Add a fourth line with the cable length if the cable is intact. Send one or two photographs at the right scale so that the desk can confirm what the model string says.

The model string alone, written in the body of the message, often closes the request without further questions. The Omron E3ZM-T81 (score 89.26) and the E3ZM-T61 (score 89.26) are both retro-reflective sensors in the E3ZM family; the suffix T81 distinguishes a longer sensing range from the T61's shorter range, and the 2M suffix identifies the cable length. A request that says "E3ZM-T81 2M, need 4 pieces" arrives at the desk with the working identification already done. The desk's job is to check availability, condition, and per-line indicative price.

For sensors in the E3S family, the same discipline applies. The E3S-CD12 (score 89.18) is a diffuse-reflective sensor in the E3S family; the suffix CD12 identifies the sensing distance and the output configuration. The E3SLS10XB4 (score 89.26) is a slot-type sensor with a fixed cable. The E3SR87 (score 89.18) and the E3SR67 (score 89.18) are retroreflective variants in the same family; the trailing 7 versus 8 distinguishes the response time. A request that arrives with the model string and the cable length usually closes within one business day. For sensors in the E2 family, the E2C-X1R5AH (score 89.18) and the E2BS08KS02MCB120OMS (score 89.18) carry model strings whose suffixes encode the housing, the connector, and the cable — a photograph that captures the marking and the connector ends the identification work in one round. As of September 2026, the catalog carries the full E3S family across the diffuse-reflective, retro-reflective, and slot-type variants, so most requests that arrive with a marking close within one business day.

What to send in the first message when the marking is gone

When the marking is gone, the desk's work moves from identification to triage. Three photographs usually carry enough information: one of the device in its installed position, one of the connector end of the cable, and one of any indication LEDs visible on the housing. If the device has a cover that could be opened without breaking the device, send a photograph of the inside. If the device has a nameplate on the rear or the underside that carries a model string, send a photograph of that nameplate even if the photograph is at an awkward angle.

A request that says "E3Z family, marking unreadable, cable is 2 metres, connector is M8 4-pin, output stage appears to be NPN, photo attached" is workable. The desk can resolve the family from the silhouette, the cable length from the photograph, the connector type from the photograph, the output stage from the wiring if the wiring is visible, and the model string from the intersection of those four data points. The request usually closes in one to three business days, depending on how many of the four data points are visible in the photograph.

A request that says "old Omron sensor, marking gone, please help" is not workable. The desk cannot identify a sensor from a description that does not include a model string, a family, a cable length, a connector type, or an output stage. The first message back is "please send a photograph at a scale that shows the connector and the wiring".

For sensors where the marking has been painted over by a maintenance contractor, a 5-second scrub with isopropyl alcohol often reveals the model string. Where the marking has been laser-etched into a plastic body, even aggressive cleaning will not remove it; the model string is there, just hard to read. Where the marking has been printed on a paper label and the paper label is gone, the model string is gone, and the desk works from the photograph alone.

What the desk does once a part is identified

Once a part is identified, the desk moves through a fixed sequence. The desk checks the catalog for the MPN. If the MPN is in the catalog, the desk reads the part's score, the part's stock state, the part's condition state, and the part's data-sheet link from the catalog record. The catalog record for an Omron E3ZM-T81 (score 89.26) carries the family, the suffix, the cable length, the connector variant, and the data-sheet revision. The desk reads those fields off the catalog, not off the photograph.

If the MPN is not in the catalog, the desk checks the equivalent family in the catalog. The Omron E3Z family includes the E3ZM-T81 2M (score 89.26), the E3ZM-T61 2M (score 89.26), the E3ZM-D62 2M (score 89.1), the E3ZM-R61 2M (score 88.94), the E3ZMT815M (score 89.02), and the E3S-CR61 (score 89.02) in the slot-type variant. The desk works from the catalog, not from the photograph, when the catalog carries the MPN.

If the MPN is in the catalog but the requested quantity exceeds the stock state, the desk reads the catalog record and reports the actual stock state. The desk does not estimate, does not extrapolate, does not guess at future stock. The catalog record carries the actual stock state as of the catalog update timestamp.

How the per-line quotation moves from "we can quote" to "we can ship"

When the desk has identified the MPN and confirmed availability, the desk writes a quotation that lists the MPN, the family, the suffix, the cable length, the connector variant, the quantity, the condition, the per-line indicative price, the per-line MOQ, and the per-line lead time. The quotation is per-line because the desk works per-line: a 40-line mixed-brand BOM carries different conditions, different MOQs, different lead times, and different prices per line.

For a single-MPN request, the per-line quotation is one line. For a multi-MPN request, the per-line quotation is one line per MPN. For a BOM that arrives without model strings, the desk works back to the model string through the identification workflow described above, and the per-line quotation is then one line per MPN. The desk does not combine lines into a single indicative price because the desk cannot combine conditions across lines.

The quotation does not carry a fixed lead time. The desk states "lead time per order" because the actual lead time depends on the actual condition state of the actual stock, which depends on the actual moment of the actual order. The desk does not carry a fixed transit time either; transit depends on the actual route, the actual incoterms, and the actual customs clearance at the destination, all of which the desk reports as "per quotation".

When the marking is unreadable and the photograph is not enough

The desk closes the request without a quotation in three situations. The first is when the marking is unreadable, the photograph is not enough to identify the MPN, and the buyer's engineer cannot add any further data. The second is when the MPN is identified but the requested MPN is on a restricted list — for example, an MPN whose follow-on family is in scope for a customer qualification that the desk cannot certify. The third is when the MPN is identified but the desk cannot read the catalog record for the MPN, because the catalog does not carry the MPN, and the desk has no equivalent family in the catalog.

In all three situations, the desk writes the request down, returns the desk's reading of the photograph, and asks the buyer for further data. The desk does not estimate the MPN, does not guess at the family, and does not write a quotation that says "indicative for an equivalent family" without explicit buyer agreement.

What the desk does not do

The desk does not repair the device. The desk does not refurbish the device. The desk does not issue a certificate of conformity for the device. The desk does not write a report that asserts the device is interchangeable with a different family; that work belongs to the buyer's engineering function. The desk does not write a safety case for the device. The desk does not quote a fixed lead time. The desk does not quote a fixed transit time. The desk does not estimate customs clearance at the destination.

For a buyer who needs a repair, a refurbishment, a qualification report, a safety case, or a fixed lead time, the desk writes the request down and refers the request to the appropriate specialist. The desk works on finding parts, not on certifying parts, and the desk's quotation reflects the desk's actual scope.

What this means for the inquiry workflow

The inquiry workflow is a fixed sequence. The buyer sends a photograph and a marking. The desk reads the model string off the marking and the connector and the cable length off the photograph. The desk checks the catalog. The desk writes a per-line quotation. The buyer confirms or amends the per-line quotation. The desk places the order. The desk reports the order back to the buyer with the per-line condition and the per-line indicative price locked.

The desk does not work from a single crop-tight photograph. The desk does not work from a description that does not include a model string. The desk does not estimate a price for an MPN that the desk has not read off a catalog record. The desk does not combine conditions across lines. The desk does not write a quotation that includes a fixed transit time or a fixed lead time. The desk works from the photograph, the marking, and the catalog record, in that order, and stops at the first point where the desk cannot read any one of the three. Send your BOM or the photograph and the marking through the inquiry form, and the desk replies with a per-line quotation inside one business day where the marking and the photograph identify the MPN.

Worldwide delivery when the marking and the photograph tell the desk what the MPN is

For a buyer outside China, the desk ships the identified MPN under the incoterms stated on the quotation. The desk works EXW from the desk's warehouse, FCA from the desk's loading dock, DAP to the buyer's named place, or DDP to the buyer's named place where the quotation states DDP. The desk does not guarantee a fixed transit time; the desk's quotation states the route and the incoterms and lets the carrier state the actual transit time. The desk ships to Russia, to the Russian regions, and to the CIS under DDP where the quotation states DDP, and the desk does not write the route as a service commitment.

The desk does not issue EAC certification or TR CU certification. The desk does not act as an importer of record for the buyer. The desk does not write a customs declaration that names a tariff heading outside the desk's working scope. The desk writes the desk's quotation as a desk's quotation, and the buyer's customs broker or the buyer's qualified specialist signs the customs declaration at the destination.

We screen end users and end uses, classify before quoting, and decline transactions that cannot be screened. Independent distributor, not an authorised channel.

What an inquiry from Russia or the CIS looks like in practice

A buyer in Moscow with a legacy Omron E3S-CD12 sensor on a bottling line, the marking partly worn, sends a photograph, a wiring sketch, and the line's PLC family in the body of the inquiry. The desk reads the model string off the photograph, confirms the wiring against the catalog's data-sheet link for the E3S-CD12 (score 89.18), and writes a per-line quotation with the MPN, the condition, the per-line indicative price, the per-line MOQ, and the per-line lead time as "per order". The quotation is per line; the buyer confirms or amends; the desk places the order; the desk reports back.

A buyer in Novosibirsk with a legacy Omron E2C-X1R5AH proximity sensor (score 89.18) on a coal-handling conveyor, the marking partly painted over, sends a photograph of the connector, a photograph of the cable, and the part's function in the inquiry body. The desk reads the connector off the photograph, the cable length off the photograph, the function off the description, and writes a per-line quotation for the E2C-X1R5AH or for the equivalent in the E2C family depending on the catalog record. The quotation is per line; the buyer confirms; the desk ships.

A buyer in Kazakhstan with a legacy Omron E3SLS10XB4 slot-type sensor (score 89.26) on a packaging machine, the marking fully readable, sends the model string in the body and the photograph of the connector. The desk reads the model string, confirms the catalog record, and writes a per-line quotation in one step. The quotation is per line; the buyer confirms; the desk ships.

The takeaway

Send a photograph that captures the model string, the connector, and the cable. Send a marking when the marking is still readable. Send the function of the part in the body of the inquiry, not as a comment. The desk works from the photograph, the marking, and the catalog record, in that order, and the desk's per-line quotation is the desk's per-line quotation. For a buyer who needs a per-line quotation for a 40-line BOM that arrives without model strings, the desk's identification workflow applies line by line, and the desk's quotation reflects the desk's actual identification work per line. Request a quote through the inquiry form on the desk, attach the photograph and the marking, and the desk replies with a per-line quotation inside one business day where the marking and the photograph tell the desk what the MPN is. The desk is an independent distributor of industrial automation parts, not an authorised channel for any of the brands it ships from, and the quotation reflects that scope.

By aoctrl sourcing desk · 2026-09-25 · independent distributor · not an authorised channel for any brand listed · data through September 2026

Data Notes:

The Omron MPNs cited (E3ZM-T81 2M, E3ZM-T61 2M, E3SLS10XB4, E2C-X1R5AH, E3SR87, E3SR67, E3S-CD12, E2BS08KS02MCB120OMS, E2FQX10F1, E3ZM-D62 2M, E3SCL25MOMS, E3SCD11, E2C-EDR6-F, E3ZMT815M, E3S-CR61, E3SCL2M1J03MOMS, E3SCL15MOMS, E3ZM-R61 2M, E3SDCP21IL2OMS, E3SCT615MOMS, E2K-X15MY1, E3SCT112MOMS, E3SCL22MOMS, E2K-X4MY1) and their catalog scores are read from the aoctrl catalog and are not estimates.
The desk does not write a quotation with a fixed lead time or a fixed transit time; both are per quotation and per order.
The desk does not issue EAC certification, TR CU certification, or any qualification report that asserts the device is interchangeable with a different family; that work belongs to the buyer's qualified specialist.

FAQ

What can a photo and a marking actually tell an independent desk about a legacy part?

A photo and a marking together carry the silhouette of the device, the model string if it is still on the housing, the connector type, the cable length, the cable colour code, and the wiring of any visible terminals. They do not carry the firmware revision burned into a microcontroller that can only be read over the programming port, the factory calibration certificate, or the production-lot trace.

How do I photograph a legacy sensor so the desk can identify it?

Capture the device at a scale that shows the connector and the cable. Capture the marking if the marking is still readable. Capture the wiring if the wiring is visible. Avoid crop-tight photographs of the front face; the front face rarely carries the model string. Send the photograph through the inquiry form and the desk replies inside one business day.

Can the desk identify an Omron E3Z-family sensor from a single photograph?

Yes, when the photograph captures the marking and the connector and the cable. The Omron E3Z family includes the E3ZM-T81 2M (score 89.26), the E3ZM-T61 2M (score 89.26), the E3ZM-D62 2M (score 89.1), the E3ZM-R61 2M (score 88.94), and the E3ZMT815M (score 89.02), and the family works on a suffix system that distinguishes the body style, the sensing distance, the output configuration, and the cable length. Send the photograph via the inquiry form and the desk returns a per-line quotation inside one business day where the marking and the photograph identify the MPN.

What if the marking is gone and the photograph is not enough?

The desk writes the request down and returns the desk's reading of the photograph. The desk then asks for one of: a photograph of the inside of the device, a photograph of the connector, a photograph of any indication LEDs visible on the housing, or a second photograph at a scale that shows the wiring.

Does the desk quote a fixed lead time on a per-line quotation?

No. The desk's quotation states lead time per order because the actual lead time depends on the actual condition state of the actual stock, which depends on the actual moment of the actual order.

Does the desk ship to Russia and the CIS?

The desk ships under the incoterms stated on the quotation. The desk works EXW, FCA, DAP, or DDP, and where the quotation states DDP, the desk ships under DDP. The desk does not write the route as a service commitment. We screen end users and end uses, classify before quoting, and decline transactions that cannot be screened. Independent distributor, not an authorised channel.

What does the desk not do from a photograph and a marking?

The desk does not repair the device, does not refurbish the device, does not issue a certificate of conformity, does not write a qualification report that asserts the device is interchangeable with a different family, does not write a safety case, and does not quote a fixed lead time or a fixed transit time. The desk is an independent distributor, not an authorised channel for any brand.