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These figures are not competing estimates of the same population. They come from three different ZoomEye queries: one looked for hosts answering on TCP port 102, one classified devices as PLCs, and one fingerprinted assets as Siemens S7. Each filter asks a different question, so each can return a different total.
What the three counts represent
An excerpt from the exact-title article reports the following ZoomEye results: 161,907 hosts answering on TCP port 102, 95,749 devices classified as PLCs, and 173 assets fingerprinted as Siemens S7. The excerpt presents them as results of separate queries, not as counts of one identical set of devices. The excerpt does not provide query strings or collection details, so these figures cannot be independently reproduced from the available information.
| Reported result | Filter being described | What it indicates |
|---|---|---|
| 161,907 hosts | Responding on TCP port 102 | A service was reachable and answered on that port, according to the reported query. |
| 95,749 devices | Classified as PLCs | The query’s device classification identified PLCs; the excerpt does not establish the classification method. |
| 173 assets | Fingerprint identified as Siemens S7 | The query matched a Siemens S7 fingerprint; this is a narrower product-identification result. |
These categories need not be nested perfectly. A port scan counts responders regardless of whether the service is a Siemens controller; a broad PLC classification is a device-category filter; and an S7 fingerprint is a product-specific match. The excerpt does not state whether results were deduplicated or how the filters overlap.
Why TCP port 102 matters—and what it does not prove
Siemens documentation describes RFC 1006 over TCP port 102 as S7 communication with a controller for programming and diagnostic purposes. That makes the port relevant when discussing Siemens S7 systems, but a response on TCP 102 alone does not verify that the endpoint is a Siemens PLC. Siemens STEP 7 V21 cybersecurity documentation identifies this communication path.
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Siemens ProductCERT also describes device management over TCP port 102 (ISO-TSAP) for S7-1200 devices. Its advisory concerns specified device versions and vulnerabilities, rather than every endpoint that answers on the port. Siemens ProductCERT advisory recommends protecting network access with appropriate mechanisms.
Reachability is not the same as vulnerability
A reachable service can warrant security attention, but the reported port count does not show that those hosts are vulnerable or exploitable. CISA’s 2021 advisory for a vulnerability in the Siemens SIMATIC NET CP343-1 describes a denial-of-service condition involving TCP port 102 and recommends limiting access to the port to specific IP addresses, for example with a firewall. That is product-specific guidance, not evidence that the 161,907 hosts in the reported query were affected. CISA advisory for Siemens SIMATIC NET CP343-1
In its S7-1200 advisory, CISA/ICS-CERT states: “Critical devices should not directly face the Internet.” The advice is to reduce exposure, not to infer that every Internet-reachable response represents a compromised or vulnerable controller. CISA/ICS-CERT S7-1200 advisory
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The counts are reported search results, not independently verified totals of unique devices or vulnerability findings. The available excerpt does not supply the exact ZoomEye query syntax, scan timestamp, geographic scope, or deduplication method. Because those details affect what a search engine counts, treat the values as point-in-time query outputs whose full methodology is not established here.
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- PC adapter USB is the optoelectronic isolated adapter for industrial design. There is anti-surging& anti-lightning protection for the USB and RS485 interface. It support hot plug. Its suitable for S7-300/400/200 series PLC. In particular, it applies to the strong interfere industrial scene and the safeguard in the circuit guarantees the safely running of the system.
- 7972-0CB20-OXAO is optical isolation for industrial design in USB port and RS485 ports are equipped with surge protection and lightning protection circuitry for Siemens S7-300 / 400 and S7-200 series PLC full range PLC. Particularly suitable for interferences fragile industrial field communication port, the circuit in a variety of protective measures to ensure the safe operation of the system.
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- Features and technical indicators: software version STEP7 V5.2 and above, STEP7 Micro /Win 4.0 and above. MPI baud rate 19.2Kbps, 187.5 Kbps. PPI baud rate 9.6Kbps, 19.2Kbps, 187.5Kbps. The MPI port automatically adapts to the communication rate of 19.2Kbps and 187.5Kbps, 500Kbps, 1.5M Kbps DP master communication.
- Working temperature: -20-+75°C, long-distance communication, communication distance 1000m (RS485 end, when the baud rate is 187.5Kbps)
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- Port 102 result: indicates hosts answering on that port in the reported query, not a confirmed Siemens device count.
- PLC result: reflects a generic device classification, not a count of Siemens S7 systems.
- S7 result: reflects a product fingerprint match, not a vulnerability assessment.
- All three: lack enough disclosed query and collection details in the excerpt for independent reproduction.
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