fix: Fix IntegrityId and response parsing for Browse.

[bvanelli]

This PR does two things for the Browse to work (tested on a S7 15XX):

• Shortens the expected response from 14 to 10 bytes since the response is not expected to carry the SessionId: Can be found on CreateObjectResponse.DeserializeFromPdu, where the SessionId is not expected to be available on the response (only request, therefore you need 4 bytes less).
• Adds the IntegrityId as being optional for the Browse symbolic read. I believe this has to be a incremental number, otherwise the PLC drops the connection. You can this as optional on GetMultiVariablesRequest.Serialize.

There needs to be a "permanent" solution for integrating an incremental IntegrityId, but this changes were enough to acomplish a basic browse.

Here is my example browse:

async def main() -> None:
    async with S7CommPlusAsyncClient() as client:
        await client.connect(PLC_HOST, PLC_PORT, use_tls=True)
        if not client.session_setup_ok:
            logger.warning("Session setup incomplete — browse results may be incomplete")
        variables = await client.browse()
        if not variables:
            print("No variables found.")
            return
        print(f"\nFound {len(variables)} variable(s)\n")

As a heads up, I have tested the async functions, but not the sync one.

[gijzelaerr]

Thanks for this @bvanelli — both fixes are well-motivated and the response header change is independently confirmed by @EliTheCoder's hex dump analysis in #763.

Response header 14 → 10 bytes — correct. The CreateObject response doesn't carry a SessionId field (only the request does). The S7CommPlusDriver reference confirms this. The 4-byte misalignment was causing the parser to consume the entire attribute tree (including ServerSessionVersion) as fake "object IDs".

IntegrityId — a few things to address:

1. Sync/async inconsistency: the async read_symbolic passes with_integrity=False, but the sync _s7commplus_client.py read_symbolic wasn't updated — it still calls _build_symbolic_read_payload(access_area, lids, symbol_crc) with the default with_integrity=True. These should behave the same way.

2. _integrity_id_read initialization: the async client references self._integrity_id_read but I don't see it being initialized or incremented anywhere in this diff. Does the base class set this up? If not, this will raise AttributeError.

3. with_integrity=False for browse: removing the integrity ID entirely for browse reads works as a workaround, but as you note it needs a permanent solution. Worth a # TODO and maybe a tracking issue so it doesn't get lost.

The header fix is solid and I'd be happy to merge that independently if you want to split it out — it unblocks V2 session setup for anyone hitting the framing bug.

[bvanelli]

Hi @gijzelaerr ,

The sync read_symbolic now passes with_integrity=False a5a7508. I tested it with the S7 on the sync path too.

_integrity_id_read initialization

This is initialized here:

python-snap7/s7/_s7commplus_async_client.py

Line 76 in 9678bfa

self._integrity_id_read: int = 0

I believe the incrementing was never implemented, needs to be done in a follow up. It would be a lot easier to tests once we have a stable working browse. It should not matter as of now as this is ignored.

For S7CommPlusClient, I did not include it since it belongs to S7CommPlusConnection, not S7CommPlusClient. Not sure how you want this architecture to look like in the future, so I did not touch it.

Testing

Before my changes (full)

DEBUG snap7.connection: TCP connected to 192.168.101.34:102
DEBUG snap7.connection: Sent COTP Connection Request
DEBUG snap7.connection: Negotiated PDU size: 1024
DEBUG snap7.connection: Unsupported COTP parameter: code=0xc1, length=2
DEBUG snap7.connection: Unsupported COTP parameter: code=0xc2, length=16
DEBUG snap7.connection: Received COTP Connection Confirm
INFO snap7.connection: Connected to 192.168.101.34:102, PDU size: 1024
DEBUG s7.connection: === InitSSL === sending (26 bytes): 72 01 00 12 31 00 00 05 b3 00 00 00 00 00 00 00 00 30 00 00 00 00 72 01 00 00
DEBUG snap7.connection: Sent 33 bytes: 03 00 00 21 02 f0 80 72 01 00 12 31 00 00 05 b3 00 00 00 00 00 00 00 00 30 00 00 00 00 72 01 00 00
DEBUG snap7.connection: Received TPKT: version=3 length=31 payload (27 bytes): 02 f0 80 72 01 00 10 32 00 00 05 b3 00 00 00 00 70 00 00 00 00 00 00 72 01 00 00
DEBUG s7.connection: === InitSSL === received (24 bytes): 72 01 00 10 32 00 00 05 b3 00 00 00 00 70 00 00 00 00 00 00 72 01 00 00
DEBUG s7.connection: InitSSL response: version=V1, data_length=16
DEBUG s7.connection: InitSSL response body (20 bytes): 32 00 00 05 b3 00 00 00 00 70 00 00 00 00 00 00 72 01 00 00
DEBUG snap7.connection: Sent 228 bytes: 03 00 00 e4 02 f0 80 16 03 01 00 d8 01 00 00 d4 03 03 0c 47 79 99 78 4f bc 61 3f be f0 62 e4 d8 48 db 90 23 ed fc d0 c5 91 a6 eb 5e 4c 60 92 95 f6 7f 20 bf f5 67 0d c6 56 97 8f 2b 7c 94 9b ad 16 62 3b 60 bf dc 64 00 2d 65 e7 58 e2 bc 6f f8 b3 2a 2a 00 06 13 02 13 03 13 01 01 00 00 85 00 0b 00 04 03 00 01 02 00 0a 00 08 00 06 00 1d 00 17 00 18 00 23 00 00 00 16 00 00 00 17 00 00 00 0d 00 2a 00 28 09 05 09 06 09 04 04 03 05 03 06 03 08 07 08 08 08 1a 08 1b 08 1c 08 09 08 0a 08 0b 08 04 08 05 08 06 04 01 05 01 06 01 00 2b 00 03 02 03 04 00 2d 00 02 01 01 00 33 00 26 00 24 00 1d 00 20 5c 15 ed f6 bd 7e 49 6f 2e eb 63 ce 81 b3 0b 6b 6b c0 92 e4 9f db ea 47 f1 8d 26 da c5 f0 27 4e
DEBUG snap7.connection: Received TPKT: version=3 length=1024 payload (1020 bytes): 02 f0 80 16 03 03 00 7a 02 00 00 76 03 03 1f d3 46 27 d2 66 56 bf a9 bf 33 f8 53 be 96 8f ea 0b f7 31 e1 07 c2 3d 65 4f 68 5f 54 dc f4 73 20 bf f5 67 0d c6 56 97 8f 2b 7c 94 9b ad 16 62 3b 60 bf dc 64 00 2d 65 e7 58 e2 bc 6f f8 b3 2a 2a 13 02 00 00 2e 00 2b 00 02 03 04 00 33 00 24 00 1d 00 20 e7 25 e6 b8 db 6c c7 ec d0 69 6d ab a9 d1 68 cf 64 fa 08 95 29 0a 9d 97 a8 a5 d8 0e 12 00 3b 54 14 03 03 00 01 01 17 03 03 00 17 3a 33 9f b9 68 c6 e0 0a 31 c0 38 3e b4 16 b7 04 ca e7 bb e2 e2 ee cc 17 03 03 02 c3 d4 bc 7a e7 2f 78 a3 60 8e 3c 7f 15 49 6e d2 ee 0f 80 c6 59 a2 3a 3b 47 c7 b1 07 b9 c3 17 27 75 91 91 c0 31 99 d7 c5 10 c8 43 e7 21 6d 4d a1 e9 02 42 32 20 64 38 d1 62 0f 87 87 51 ff 3f bd 3d 68 5e e1 62 b8 a5 ec 91 6f 72 d5 6f 62 58 3e f1 2f 66 12 c6 be 3f b0 65 fd cc dd ba 10 33 2c 28 f0 33 aa d8 a3 c3 ce f5 c9 02 d2 b1 f8 5c 6c d5 46 5a ba 83 82 d8 fd 75 65 20 ba 36 04 0c c9 75 9d 64 06 c3 9b 48 9b e7 a2 d6 49 f1 48 0a e3 e4 b0 42 41 c3 44 7c 3a 64 60 56 2a 4b a9 6d 82 c6 65 3c 98 fd 68 88 9f 99 e8 d7 b4 00 7c 8f 5e 17 ee 2a e6 43 f4 4f 1d 42 a3 52 2d db 47 85 6b 52 b8 e5 c2 05 b5 3f b8 72 18 e9 bb 20 61 93 3b d6 a3 27 62 a7 73 b0 ed ad ef 6e 32 02 6e 05 b3 aa 3d 1f 9c 33 85 6f dd 1e 63 e5 14 a9 dd f7 8a a2 ff 95 34 06 27 a4 13 a9 b2 8c 77 37 71 58 13 7f e2 6f 5f e2 7d ee a2 39 cf 65 27 62 ca ef a2 be c9 41 19 14 12 f2 13 ed 28 cd 2b 4c 31 1a 4e b8 e1 5b f6 ae b2 cd 51 20 24 34 e3 5a e0 e1 c8 d9 36 e3 6e 8d d0 a2 c5 30 67 f4 12 ca a1 3d cc 76 6e bb c1 08 ae 26 1f 18 d6 35 c3 05 87 fa 0a 40 b0 cf 3e b8 99 1d fb 73 f4 9f 4e 57 0a a4 30 ab a5 35 84 88 36 71 89 b5 70 7d 0b 3c ff 00 b4 74 dc b6 3a e1 0c 00 d3 83 98 bc a7 d2 27 07 ed d9 28 e0 e6 f9 b1 91 44 f8 c7 0d dd f7 f3 8e 47 51 93 3a dd 4d a4 de 8d 50 12 95 a7 ec e8 fb 8c 4d 7d b9 01 bf 5c a1 79 6f 32 15 62 bd b0 bf f9 ea db 27 8e a0 f4 f2 f0 fa de 98 e6 dc 09 9e 9d 4e 1e 95 79 d6 40 dc f3 c6 0e e0 ca 7b 4c 23 d3 8e bb cc 0e a2 7e 38 4b ce ac 57 d2 59 b6 f6 09 a0 c1 35 80 da 8a a5 34 b0 67 03 d3 ba 38 33 0f 93 6f 46 e8 c9 f7 3c 79 0b d6 31 49 d2 8d 93 d4 b4 39 bb 9d fb 44 e7 ca de 38 bb 31 85 72 91 20 fd ca a7 d6 c6 66 65 b2 8e 36 e8 e2 f5 ba de 24 6b 9a 79 95 e0 14 4c 03 6b f3 3d ce c2 a4 75 e9 e7 6d 50 22 e7 74 5a 13 ec 40 c3 e6 bc 23 27 0d dc 86 a2 ce 5a 24 75 ae 8d b3 0c 34 4a 35 2d ab 6f 68 47 b8 46 69 bf 51 46 b5 11 44 d7 91 d3 f8 db 67 52 01 6a 44 d1 42 ce b6 bf 29 e4 4e f0 ad eb ca 08 e8 81 77 78 c4 14 82 32 be ab 5b 31 e7 a1 d8 2a 9b 83 24 1e fc 5c 9f a7 78 fb 7c b8 5a 24 c6 12 ca 3e 1e 5b 17 45 90 16 53 0e 7b 4e 93 81 b6 cb 46 d4 c4 5c 08 1f ff 00 3c 9b 51 80 d7 cf 5d d0 5a e9 fc cc e4 3b d1 0e cc fb e6 6e 85 02 38 54 93 17 03 03 00 5f 46 b6 36 35 93 25 4b 1c c6 b8 3b 94 ed dc a7 9b 76 bf 63 8c 46 33 3d e2 5c be dd 08 55 56 77 cd 3f 4a 5a 89 3d 1e a9 0b d0 48 9f 40 ad 10 2b 74 09 56 4a 2d 98 17 92 35 d4 66 fe 09 61 f0 a3 65 a9 6b 7f de af 9d ed 18 d0 d8 a6 ec bb 74 22 b4 00 dd 8f 39 68 de 3a c7 19 85 ad b7 34 c9 ca 17 03 03 00 45 0f 42 e9 63 55 32 59 db 0a 4a 9b 9b 51 70 8c cd 9e c5 dd b3 ea c3 b0 80 e4 17 0b 11 12 fb f3 98 87 ca c7 e3 43 4a 5c
DEBUG snap7.connection: Received TPKT: version=3 length=37 payload (33 bytes): 02 f0 80 45 78 eb 87 8b 15 58 bb f0 f6 5f dc 3f fd 55 3b f4 b5 ee f6 53 4b 47 89 dd 79 43 8d c2 cb
DEBUG snap7.connection: Sent 87 bytes: 03 00 00 57 02 f0 80 14 03 03 00 01 01 17 03 03 00 45 a0 fa f9 b9 82 f7 a2 03 85 ae 53 12 e7 d2 ce 60 87 82 90 67 c3 5b 0c af ad ab f8 13 8f df 97 04 e5 4d ab 41 e0 c6 87 7e ed af 7b 96 f9 3c 31 50 a6 01 62 13 09 a6 bb 30 8b d2 1c 8a 7f 49 e2 58 28 43 36 6a 14
WARNING s7.connection: Could not extract OMS exporter secret: 'SSLObject' object has no attribute 'export_keying_material'
INFO s7.connection: TLS 1.3 activated (tunneled inside COTP frames)
DEBUG s7.connection: === CreateObject === sending (66 bytes): 72 01 00 3a 31 00 00 04 ca 00 00 00 01 00 00 01 20 36 00 00 01 1d 00 04 00 00 00 00 00 a1 00 00 00 d3 82 1f 00 00 a3 82 2c 00 12 80 c3 c9 01 a1 00 00 00 d3 81 7f 00 00 a2 a2 00 00 00 00 72 01 00 00
DEBUG snap7.connection: Sent 95 bytes: 03 00 00 5f 02 f0 80 17 03 03 00 53 01 50 cc c5 bc d2 bd 7a de 15 c8 3b 16 f3 55 2d ec 75 9a 1f 3c 08 6c 18 b1 85 08 51 2e 9a d8 37 13 3c 2c f8 a8 62 20 19 38 c6 4d 95 fe 6d ca 48 c4 4f 09 02 85 9e 4b 49 09 4a b9 0a b5 97 a8 55 9f 6e 23 1b 51 64 59 04 0b af a0 15 09 06 90 16 c7 a2 eb
DEBUG snap7.connection: Received TPKT: version=3 length=517 payload (513 bytes): 02 f0 80 17 03 03 00 fa c7 22 e7 f8 ab 52 74 29 ac c5 db 3b 67 5e 07 a9 64 38 99 dc 36 3f 5f 82 5e e4 f2 d2 0b 77 9d f0 ec bd a6 81 40 cd 9f a8 4b 6c e4 f6 5c f9 09 25 a0 f8 8f e1 d2 bb c4 95 8d a8 e2 a2 a5 85 c8 2b f7 28 3d 51 71 0e b3 ac ba 34 80 1a 19 2e ee 8d e0 10 cd 57 54 33 df 0a 76 d1 5e 81 d4 21 44 fc 0a 41 76 20 fe 0c 38 6b d3 35 65 3d ce 90 2e d0 99 70 3c 98 c0 20 bb 7a 24 94 7b c8 a7 1b 9d 38 97 ca ce 77 d0 c4 de f0 61 07 aa 4f 26 0b 9c 1a 89 4d 77 d2 9f d1 a9 fd 3e 82 e4 65 3f 99 1c d3 b1 60 16 18 d8 f4 ef 0d f3 a2 52 c2 f6 38 28 33 cf fd d1 e4 98 b5 86 5a 66 de f8 97 dd b9 f0 b9 42 ca 66 17 78 f1 fc 74 f7 ba 37 c6 28 5c b0 ca 0b 3c 44 64 4c 1d 0f b3 41 73 31 a0 6b 5d 20 21 a4 af c4 34 c4 1d 7c 50 b1 f4 92 8a 20 ca a1 21 fd 8b 1a d7 ec 1b 88 20 30 01 17 03 03 00 fa 2f 1a 39 2b fc 19 dc 36 38 c2 4c cc bd 35 39 da 78 62 79 c4 2b 88 71 b2 33 45 b2 f0 85 52 77 ec 9d 87 69 1a d3 60 67 48 f8 1f 91 d2 a3 b2 fd b7 c4 55 77 1d 95 b7 dc e5 d3 66 f9 0a 4c 12 16 07 4f e1 dc 3f 26 bc 4e dc a5 1c b6 c0 af c9 2e aa 3e df 9a 75 44 28 61 6a d2 9e bb 0c 0c c0 3d 78 00 dd 88 1c ec 81 07 51 90 f8 06 39 90 57 35 c5 3b cc 3c 99 7d 2f 84 19 88 2f 3b 73 7a 2b 6e 29 60 9f c6 59 9d c2 90 6e 35 17 41 a1 d7 01 5e de d9 ec 93 5d 19 75 2d cb 4e a8 1e 9e a1 cc 8f 27 ca 4d ed be cc ad 72 fd 29 a2 f8 81 3c 8c 68 f9 15 f4 cd 48 9b b8 cb 97 85 3c 4f 4d 57 fd 82 e2 b9 e0 53 0f c2 6f 88 6f 3b 58 58 74 94 67 42 33 e9 77 14 f2 32 ee 72 34 82 45 18 21 3a 32 e4 7f 89 eb 17 4b b4 89 87 45 76 30 ab 17 78 46 79 4d 3f 55 01 e6 dc c4 98 8d b1 38
DEBUG snap7.connection: Received TPKT: version=3 length=254 payload (250 bytes): 02 f0 80 17 03 03 00 f2 39 49 ea 7e 34 9a b9 db 00 7a ac 57 17 3d b0 e7 06 d3 b6 d6 5b 6a 14 59 4a f6 d7 3d ed 8e 64 35 82 fa 6f a6 d1 68 6e b3 23 f4 3c 8a 35 ec ee f2 08 9a 47 c0 06 d7 c1 16 12 8a 97 58 60 38 86 72 60 ac e1 51 41 8e 0f a1 0f 24 97 c8 4b 41 a0 9e d6 2c 53 e3 ac f6 25 d2 74 ab b0 9a 85 19 5f d0 34 c2 fb e6 6e b7 d1 15 ff a4 13 5a 00 06 70 da 9d 8c b8 95 ea fa 5e 3c 23 44 f5 d7 0b f3 c9 31 fa 22 4e 6e e5 ad 5d 82 1a 1b b3 87 6b 9c 64 26 40 71 06 f9 2e 68 40 88 5b 5d 90 0c 0b 97 46 e3 63 62 fa 03 0b 16 38 56 3b 9f 9a 78 36 29 d0 5c c3 37 ac bc 77 67 70 f7 47 8b eb e7 04 a7 85 9b 56 33 a1 7a 30 e9 c8 70 b6 27 bf 0e 75 d8 d2 39 19 2e 34 63 4c 88 dd 81 09 bc 91 7c 31 82 ff 3b c9 05 c1 09 cd 6a f9 5c ff af 53 98 05 b0 a0 f8 9f 11
DEBUG s7.connection: === CreateObject === received (225 bytes): 72 01 00 d9 32 00 00 04 ca 00 00 00 01 36 00 02 87 80 80 99 30 87 80 80 99 31 a1 00 00 01 20 82 1f 01 00 a3 81 69 00 15 13 30 30 3a 31 38 31 42 37 42 30 38 34 37 44 31 31 36 39 34 a3 82 2b 00 04 02 a3 82 2d 00 15 1c 4f 4d 53 50 5f 31 32 2e 30 30 2e 30 33 2e 31 39 5f 33 35 2e 31 39 2e 30 30 2e 30 31 a3 82 2f 10 02 14 ff 3e 4a 55 84 af 61 5a 0a cb d4 c5 42 e0 f9 90 49 a8 4c e8 a3 82 32 00 17 00 00 01 3a 82 3b 00 04 86 00 82 3c 00 04 85 40 82 3d 00 04 84 81 84 40 82 3e 00 04 84 81 84 40 82 3f 00 15 1a 31 3b 36 45 53 37 20 35 31 32 2d 31 43 4b 30 31 2d 30 41 42 30 3b 56 32 2e 39 82 40 00 15 0a 32 3b 33 34 33 36 36 32 34 37 82 41 00 03 00 03 00 a2 00 00 00 00 72 01 00 00
DEBUG s7.connection: CreateObject response: version=V1, data_length=217
DEBUG s7.connection: CreateObject response body (221 bytes): 32 00 00 04 ca 00 00 00 01 36 00 02 87 80 80 99 30 87 80 80 99 31 a1 00 00 01 20 82 1f 01 00 a3 81 69 00 15 13 30 30 3a 31 38 31 42 37 42 30 38 34 37 44 31 31 36 39 34 a3 82 2b 00 04 02 a3 82 2d 00 15 1c 4f 4d 53 50 5f 31 32 2e 30 30 2e 30 33 2e 31 39 5f 33 35 2e 31 39 2e 30 30 2e 30 31 a3 82 2f 10 02 14 ff 3e 4a 55 84 af 61 5a 0a cb d4 c5 42 e0 f9 90 49 a8 4c e8 a3 82 32 00 17 00 00 01 3a 82 3b 00 04 86 00 82 3c 00 04 85 40 82 3d 00 04 84 81 84 40 82 3e 00 04 84 81 84 40 82 3f 00 15 1a 31 3b 36 45 53 37 20 35 31 32 2d 31 43 4b 30 31 2d 30 41 42 30 3b 56 32 2e 39 82 40 00 15 0a 32 3b 33 34 33 36 36 32 34 37 82 41 00 03 00 03 00 a2 00 00 00 00 72 01 00 00
DEBUG s7.connection: CreateObject response header: opcode=0x32 function=0x04CA seq=1 session=0x00000CB1 transport=0x80
DEBUG s7.connection: CreateObject response payload: 80 99 30 87 80 80 99 31 a1 00 00 01 20 82 1f 01 00 a3 81 69 00 15 13 30 30 3a 31 38 31 42 37 42 30 38 34 37 44 31 31 36 39 34 a3 82 2b 00 04 02 a3 82 2d 00 15 1c 4f 4d 53 50 5f 31 32 2e 30 30 2e 30 33 2e 31 39 5f 33 35 2e 31 39 2e 30 30 2e 30 31 a3 82 2f 10 02 14 ff 3e 4a 55 84 af 61 5a 0a cb d4 c5 42 e0 f9 90 49 a8 4c e8 a3 82 32 00 17 00 00 01 3a 82 3b 00 04 86 00 82 3c 00 04 85 40 82 3d 00 04 84 81 84 40 82 3e 00 04 84 81 84 40 82 3f 00 15 1a 31 3b 36 45 53 37 20 35 31 32 2d 31 43 4b 30 31 2d 30 41 42 30 3b 56 32 2e 39 82 40 00 15 0a 32 3b 33 34 33 36 36 32 34 37 82 41 00 03 00 03 00 a2 00 00 00 00 72 01 00 00
DEBUG s7.connection: Session created: id=0x00000CB1 (3249), version=V1
DEBUG s7.connection: ServerSessionVersion not found in CreateObject response
WARNING s7.connection: PLC did not provide a scalar ServerSessionVersion attribute. This is the V1-initial S7-1200 firmware band (FW < 4.5 predating TLS) which sends a Struct(314) value and requires the proprietary SessionKey handshake — not yet implemented in python-snap7 (tracked in issue #710). Falling back to legacy PUT/GET: db_read/db_write will work, browse() will not.
INFO s7.connection: V2 IntegrityId tracking enabled
INFO s7.connection: S7CommPlus connected to 192.168.101.34:102, version=V2, session=3249, tls=True
DEBUG s7.client: S7CommPlus session setup not OK, disconnecting
DEBUG snap7.connection: Sent 55 bytes: 03 00 00 37 02 f0 80 17 03 03 00 2b 33 3a 2a 28 db dd 05 4c 49 11 87 36 6b 36 87 1d 61 ec 0d 60 0c 4d 48 d3 d4 f2 d1 c3 84 a1 1b d3 7f fb f6 4a 1a a2 5a b0 16 19 ca
INFO snap7.connection: Disconnected from 192.168.101.34:102
INFO s7.client: S7CommPlus not available, using legacy S7 for 192.168.101.34:102
INFO snap7.client: S7Client initialized (pure Python implementation)
DEBUG snap7.connection: TCP connected to 192.168.101.34:102
DEBUG snap7.connection: Sent COTP Connection Request
DEBUG snap7.connection: Negotiated PDU size: 1024
DEBUG snap7.connection: Unsupported COTP parameter: code=0xc1, length=2
DEBUG snap7.connection: Unsupported COTP parameter: code=0xc2, length=2
DEBUG snap7.connection: Received COTP Connection Confirm
INFO snap7.connection: Connected to 192.168.101.34:102, PDU size: 1024
DEBUG snap7.connection: Sent 25 bytes: 03 00 00 19 02 f0 80 32 01 00 00 00 01 00 08 00 00 f0 00 00 01 00 01 01 e0
DEBUG snap7.connection: Received TPKT: version=3 length=27 payload (23 bytes): 02 f0 80 32 03 00 00 00 01 00 08 00 00 00 00 f0 00 00 01 00 01 01 e0
INFO snap7.client: Negotiated PDU length: 480
INFO snap7.client: [192.168.101.34 R0/S1] Connected to 192.168.101.34:102 rack 0 slot 1
INFO snap7.client: Auto-tuned max_parallel=4 (PDU=480)
INFO s7.client: Legacy S7 connected to 192.168.101.34:102
Traceback (most recent call last):
  File "/Users/brunno.vanelli/Documents/git/python-snap7/example/s7commplus1_browse_sync.py", line 127, in <module>
    variables = client.browse()
  File "/Users/brunno.vanelli/Documents/git/python-snap7/s7/client.py", line 303, in browse
    raise RuntimeError("browse() requires S7CommPlus connection")
RuntimeError: browse() requires S7CommPlus connection

After my changes (partial, collapsed all browse calls)

DEBUG snap7.connection: TCP connected to 192.168.101.34:102
DEBUG snap7.connection: Sent COTP Connection Request
DEBUG snap7.connection: Negotiated PDU size: 1024
DEBUG snap7.connection: Unsupported COTP parameter: code=0xc1, length=2
DEBUG snap7.connection: Unsupported COTP parameter: code=0xc2, length=16
DEBUG snap7.connection: Received COTP Connection Confirm
INFO snap7.connection: Connected to 192.168.101.34:102, PDU size: 1024
DEBUG s7.connection: === InitSSL === sending (26 bytes): 72 01 00 12 31 00 00 05 b3 00 00 00 00 00 00 00 00 30 00 00 00 00 72 01 00 00
DEBUG snap7.connection: Sent 33 bytes: 03 00 00 21 02 f0 80 72 01 00 12 31 00 00 05 b3 00 00 00 00 00 00 00 00 30 00 00 00 00 72 01 00 00
DEBUG snap7.connection: Received TPKT: version=3 length=31 payload (27 bytes): 02 f0 80 72 01 00 10 32 00 00 05 b3 00 00 00 00 70 00 00 00 00 00 00 72 01 00 00
DEBUG s7.connection: === InitSSL === received (24 bytes): 72 01 00 10 32 00 00 05 b3 00 00 00 00 70 00 00 00 00 00 00 72 01 00 00
DEBUG s7.connection: InitSSL response: version=V1, data_length=16
DEBUG s7.connection: InitSSL response body (20 bytes): 32 00 00 05 b3 00 00 00 00 70 00 00 00 00 00 00 72 01 00 00
DEBUG snap7.connection: Sent 228 bytes: 03 00 00 e4 02 f0 80 16 03 01 00 d8 01 00 00 d4 03 03 86 90 6f f5 a2 28 90 65 de fb 75 dd c2 48 01 c2 6d 5e 13 2b 28 76 69 08 6b 8f 54 e8 ae 92 ac 78 20 8a 37 6f 6c c9 fc cf d8 52 ef 69 98 cb f9 14 4c 40 d7 8b 98 2b 41 73 38 d6 2b 2e 70 c3 8a f3 7b 00 06 13 02 13 03 13 01 01 00 00 85 00 0b 00 04 03 00 01 02 00 0a 00 08 00 06 00 1d 00 17 00 18 00 23 00 00 00 16 00 00 00 17 00 00 00 0d 00 2a 00 28 09 05 09 06 09 04 04 03 05 03 06 03 08 07 08 08 08 1a 08 1b 08 1c 08 09 08 0a 08 0b 08 04 08 05 08 06 04 01 05 01 06 01 00 2b 00 03 02 03 04 00 2d 00 02 01 01 00 33 00 26 00 24 00 1d 00 20 dd 98 cb ec ac ef 52 19 e4 a1 22 cf b2 cb bf 57 51 cc af c0 e0 47 8b a3 7b 5a 97 ce b6 75 ce 0a
DEBUG snap7.connection: Received TPKT: version=3 length=1024 payload (1020 bytes): 02 f0 80 16 03 03 00 7a 02 00 00 76 03 03 43 ab ec ef e6 37 c4 40 9c 46 3e bb e9 53 ea ab ce 82 0e 0c 27 3a 40 01 7d cf b2 55 3f c2 2c c4 20 8a 37 6f 6c c9 fc cf d8 52 ef 69 98 cb f9 14 4c 40 d7 8b 98 2b 41 73 38 d6 2b 2e 70 c3 8a f3 7b 13 02 00 00 2e 00 2b 00 02 03 04 00 33 00 24 00 1d 00 20 f8 fa 64 a5 48 fb a0 3e 2f d7 7f d6 d2 bd 5c d4 4f 23 41 5a 26 ab d4 e6 79 92 e8 0b 3c d5 01 11 14 03 03 00 01 01 17 03 03 00 17 56 12 ab 68 2c b2 73 88 7f 28 9b 48 13 b2 30 81 1a aa 85 1e c2 05 24 17 03 03 02 c3 e0 9b fd 6c 97 63 6c a6 c9 9c e3 c9 84 3b 64 42 a5 88 50 79 a1 a5 b1 d0 81 f5 d0 6a b3 43 86 3f 7d e5 f5 d5 fa 2c ca d3 cb d6 2d 48 51 33 5b c0 2a 79 fa 00 52 c5 dd 35 7b 1e 9d c1 6b 47 27 4d d5 55 b8 25 5f 46 c6 17 9d d5 f2 ad 08 ef d6 0f d3 93 18 fa 0d 70 b2 af af 21 56 ee 44 57 a2 40 38 f9 fd e1 af da d5 86 c3 ac ef b7 94 3e 1c 1a f5 0d fa 4b 5e 2d 0f 88 b8 4d ba a9 05 15 38 0c 4f d8 ab c4 0a aa 22 21 0f af 2a 42 e1 9b 09 97 73 b2 e4 0c 08 20 c1 cf 24 ef 1c 07 a6 05 64 9d 98 91 61 c6 a5 0e 9c 79 a1 14 b4 17 a3 50 58 8e a7 ca ae f0 2c 60 3a 54 7c 63 65 b4 02 5a 6a b8 4d 9a 64 d8 3e dd 1f 82 90 0b e4 04 e0 35 27 a7 f4 18 8d 66 31 08 56 e8 fd 0b 95 90 4c de 9c 4c 6f 7b 05 1b ef 6d ee 61 e0 9d 9b f0 d2 c8 e8 80 3f a3 71 e9 af 7c d1 f8 f4 4b 27 7a 08 71 57 29 93 ae 07 56 f5 41 93 f5 da 98 44 21 87 b9 b4 49 b2 03 35 50 95 2b 85 61 c5 7b 9b 14 72 76 96 2d 2c 36 e6 06 85 90 8f 9c 01 3c c1 05 86 15 f1 eb 0f df 43 1c 27 93 77 d5 06 f8 9d 98 bf 5f 4a f9 e9 96 57 88 90 c2 a9 2a c7 cb 9e 63 e2 bd 7e 9d 58 b2 fe c4 00 9a d7 ad c2 62 ce 1d c7 f5 65 f2 2d 4d 4b 9d 33 db d3 95 1c d8 9b 30 9a 63 d6 25 55 9e 7d 04 4d b8 13 69 a3 ec 40 16 0c cf fb 77 5c dc f5 36 7a 31 f9 03 bb 51 84 f3 cc 4d 10 cc 42 42 1a 7e 59 e6 de d3 30 89 47 3f 85 4f cc a7 48 37 eb 1b 48 a3 11 65 08 fd 43 6d e4 f8 cf 27 a7 0d d4 51 c9 38 92 be 28 24 c8 5f 2b 20 10 50 fe a0 54 e9 2a ef f0 a1 af 25 c7 81 17 89 e2 5a 71 2e dd 11 19 c7 12 34 57 53 83 8c 6b 2a f0 dc 46 79 68 ba bb 84 db 95 66 31 09 cf c9 ad d8 ce d3 c8 bb 3c eb e4 50 49 3c 20 7e dc c4 9d 77 63 8f 3c 08 3c 30 53 de b8 93 50 ac d7 16 f1 69 6b d2 ba 20 e4 bd 84 46 8f 9f 55 2e 0d b2 65 1c 33 85 5c 32 6b 66 4c 62 13 68 5b 4a a7 53 20 91 2d c5 71 38 6b bb 61 7f 02 50 33 fe 80 90 07 8a 63 41 13 84 c1 3c df d3 66 78 20 94 03 89 ab e9 f1 0e 4e 7a c6 f5 ac 80 03 6f 4c 2e 6a d3 59 4f ef 4a cf 4d 17 d5 5c b6 36 8b 6d f7 9a 7f 5c 06 03 01 bd 5d d7 e5 89 02 4b 40 43 47 df 81 e5 73 a5 68 76 df 90 81 85 1f 84 95 e6 c8 e8 ad 4b 01 ec 0c 05 04 22 ac 98 19 16 69 bc 87 49 0d 6d a6 f6 3b 74 00 e3 6e 00 ba 6c aa 70 8e 96 67 69 7c f9 10 fc 3f 8f 0f f9 8b c1 a8 d4 ca 85 33 b9 0d e4 f6 15 f5 17 03 03 00 60 b7 d9 42 89 bd 39 af 33 73 d9 b2 da 88 3a dc e5 73 2f ac 9b 31 d8 0e 38 32 6f 25 56 fd 88 05 cc b6 81 b3 00 7e 22 95 3d 50 f4 f5 e0 70 06 75 b2 f8 6b 6d fa 45 b7 0b 6a 4b c5 cd c3 b2 0f 1e cf 55 01 cb 86 e9 70 61 51 86 8d 37 db d6 4d e6 0c a8 6b c7 d9 af dd 5c db ba 40 d6 f8 2c 53 a4 93 17 03 03 00 45 0b 90 58 c0 42 2f 6d e5 25 01 11 d3 30 fb 7a 4d ea 4f 41 cb 79 b4 55 64 8b c8 94 9f 2b 38 26 7c d8 84 f5 52 3d 72
DEBUG snap7.connection: Received TPKT: version=3 length=38 payload (34 bytes): 02 f0 80 52 cc fe b0 42 49 77 d6 c1 2f b6 29 0f fb 0f 10 ed 63 5a fb 6a db f8 69 de 61 ef d5 cc 69 70
DEBUG snap7.connection: Sent 87 bytes: 03 00 00 57 02 f0 80 14 03 03 00 01 01 17 03 03 00 45 91 8e 33 2e 33 4d 2a 25 7d 13 9b 41 a2 49 d1 09 9e 98 08 f6 06 8e 37 8c 21 e9 a6 a3 90 16 38 aa cb af c1 29 8b 30 a8 52 99 2e 07 cf a5 b1 25 8c 64 e7 3a 91 33 3a 33 5e 1a 18 71 13 82 00 52 f2 fa 18 b2 22 08
WARNING s7.connection: Could not extract OMS exporter secret: 'SSLObject' object has no attribute 'export_keying_material'
INFO s7.connection: TLS 1.3 activated (tunneled inside COTP frames)
DEBUG s7.connection: === CreateObject === sending (66 bytes): 72 01 00 3a 31 00 00 04 ca 00 00 00 01 00 00 01 20 36 00 00 01 1d 00 04 00 00 00 00 00 a1 00 00 00 d3 82 1f 00 00 a3 82 2c 00 12 80 c3 c9 01 a1 00 00 00 d3 81 7f 00 00 a2 a2 00 00 00 00 72 01 00 00
DEBUG snap7.connection: Sent 95 bytes: 03 00 00 5f 02 f0 80 17 03 03 00 53 00 d4 f7 8b 07 0e 8c 9f 74 b1 47 59 ab 89 6d 38 4c 24 cb e7 34 d8 dc cd bf 6d aa ad 83 a3 ab 47 e7 ec 26 e8 3d ba 3f fa 47 e0 1b 83 6b 67 8a d5 76 b6 be 53 46 de fb 46 e6 d5 91 fa 50 22 52 91 48 9f 8c 2c b4 39 45 19 fa 80 08 f9 ae 8e 96 b5 3f 3b 3d
DEBUG snap7.connection: Received TPKT: version=3 length=517 payload (513 bytes): 02 f0 80 17 03 03 00 fa 05 51 83 52 60 7e af f7 b6 7f 95 72 e1 1b 10 b1 64 9b 5f 31 36 22 f2 6c 68 a6 a0 58 18 ba 0e ec 92 66 22 e3 3a dc c0 3c 00 0a 5d fa 8f aa 20 bd 1b 39 0b 01 23 e3 2d 03 72 fc 00 1a 1d 32 90 b4 16 0c f6 f5 03 13 c7 3f 00 dc ec ea 59 35 5c 88 a6 80 ba 50 c6 ae c4 6a 00 db dd f1 15 58 4e 39 1e f0 84 02 dd b0 19 17 10 f0 bc 67 d3 d4 82 a1 f7 bf d2 0e c5 78 0a bf 82 2c 1e 9b 6b ec 7e 1a 7a 2b ab 06 99 dd 7c d6 e8 22 50 9f e5 e8 f5 44 df f2 7e 3e 9d 2d 32 53 fa 51 a2 13 5e e6 26 ce fa a2 b1 a6 96 76 33 91 d3 4f 63 f1 a6 35 39 54 a6 84 45 1f 79 a4 0c ea 38 bd 8a 1e 53 dc c9 82 5b 7e 64 96 21 96 41 f7 d2 ef 95 43 51 0a 82 0f 4e ac 1e 0a 06 11 7a cf 14 c8 88 32 21 04 2e 33 95 75 4b fc fe f5 1a db 1e 68 b6 17 a9 88 2f 5f 1e e5 af da 2a 14 6c c9 ac 95 17 03 03 00 fa 2e 5b cc 4c a7 55 03 c2 5e 65 64 72 27 fb 61 04 23 0a dc 2d 09 97 28 47 97 5f 78 39 c7 48 30 70 87 9a 01 28 cb 32 b6 44 30 27 20 d5 c6 19 10 50 f3 b1 d4 fb 61 d6 66 ec e1 26 f5 e2 19 c0 3b 15 74 e4 58 4d b0 b6 21 3b 67 82 2e 40 e2 c1 e7 16 a0 cd e2 bd ea e2 1e bb 18 67 dd e3 8d 73 d7 99 29 d9 7f 02 36 54 a3 12 e8 9e 9c 42 5a 84 33 2d 2e 34 3c c3 b8 dd 0c c7 a7 f7 cf 57 31 23 01 45 dc 81 cb f0 fa 3c 85 ed 16 54 54 ee 31 64 29 af 35 17 5a dc f3 7a 80 53 84 cf 01 1e 81 23 8c ef 25 5d e2 e1 7a 78 8a e7 ae c2 59 cd e0 44 bc f9 09 a2 f0 82 8a 3e 22 67 ea f1 19 ac 6e 74 b5 09 71 72 c8 3b a2 09 69 64 fb 3b 56 b2 e2 78 79 ac 90 3d c1 7d 50 01 59 0d ed 89 fa 6c eb a0 6c 02 63 88 f8 d5 a3 c7 61 e2 f5 4f 2e e3 ef 49 da 5c 5b 04 27 ed a9 23 bf 62 18 53
DEBUG snap7.connection: Received TPKT: version=3 length=254 payload (250 bytes): 02 f0 80 17 03 03 00 f2 cd ef c0 0d ce 43 16 68 1a 75 cc 4c 95 fe 11 b5 a9 d4 e1 5f 75 82 68 9c ae a4 eb 34 c1 8c 48 9c 4b 6d 9c ac ff c3 7d ff 52 1f 7f f4 57 65 58 83 c1 be fc 8f 89 ea b5 cb 11 f0 8c af a0 62 1a e7 33 4b a4 b3 e9 91 07 1e 30 b4 f6 7f 76 2c 1f b8 20 1f f2 37 58 a1 22 1e b6 5a 1e 30 81 fc 76 00 c2 43 40 66 a2 d9 71 b1 7b 4d fe d8 7a 4e 62 59 b1 9a c8 ab 91 e6 48 f4 46 82 55 c4 ae 16 68 ac b1 b0 61 98 86 d3 b8 0b 56 23 41 35 21 af 5e 8c 2b 20 f1 62 c7 eb 26 a4 92 80 d1 f2 e0 d4 cd ff 22 dd a2 70 cd 2b bb ff cf a8 14 36 f6 9c 01 84 65 9c e9 5b d8 54 d3 92 be c2 9b 83 83 54 aa 6f 83 3c 66 c0 f9 01 6b 5e a2 0d 12 cf eb 0a 7a 3b 7e 00 d7 68 68 a5 64 ad 4c 8b 5f b5 23 9b 6a 56 d5 78 6f bb c9 25 02 91 d3 af 6c 8d e2 38 64 16 95 5a
DEBUG s7.connection: === CreateObject === received (225 bytes): 72 01 00 d9 32 00 00 04 ca 00 00 00 01 36 00 02 87 80 80 99 30 87 80 80 99 31 a1 00 00 01 20 82 1f 01 00 a3 81 69 00 15 13 30 30 3a 31 38 31 42 37 42 30 38 34 37 44 31 31 36 39 34 a3 82 2b 00 04 02 a3 82 2d 00 15 1c 4f 4d 53 50 5f 31 32 2e 30 30 2e 30 33 2e 31 39 5f 33 35 2e 31 39 2e 30 30 2e 30 31 a3 82 2f 10 02 14 8b 03 cd a4 5c 6d 65 ce 18 9c a4 3a a9 4f 43 29 73 1d 91 28 a3 82 32 00 17 00 00 01 3a 82 3b 00 04 86 00 82 3c 00 04 85 40 82 3d 00 04 84 81 84 40 82 3e 00 04 84 81 84 40 82 3f 00 15 1a 31 3b 36 45 53 37 20 35 31 32 2d 31 43 4b 30 31 2d 30 41 42 30 3b 56 32 2e 39 82 40 00 15 0a 32 3b 33 34 33 36 36 32 34 37 82 41 00 03 00 03 00 a2 00 00 00 00 72 01 00 00
DEBUG s7.connection: CreateObject response: version=V1, data_length=217
DEBUG s7.connection: CreateObject response body (221 bytes): 32 00 00 04 ca 00 00 00 01 36 00 02 87 80 80 99 30 87 80 80 99 31 a1 00 00 01 20 82 1f 01 00 a3 81 69 00 15 13 30 30 3a 31 38 31 42 37 42 30 38 34 37 44 31 31 36 39 34 a3 82 2b 00 04 02 a3 82 2d 00 15 1c 4f 4d 53 50 5f 31 32 2e 30 30 2e 30 33 2e 31 39 5f 33 35 2e 31 39 2e 30 30 2e 30 31 a3 82 2f 10 02 14 8b 03 cd a4 5c 6d 65 ce 18 9c a4 3a a9 4f 43 29 73 1d 91 28 a3 82 32 00 17 00 00 01 3a 82 3b 00 04 86 00 82 3c 00 04 85 40 82 3d 00 04 84 81 84 40 82 3e 00 04 84 81 84 40 82 3f 00 15 1a 31 3b 36 45 53 37 20 35 31 32 2d 31 43 4b 30 31 2d 30 41 42 30 3b 56 32 2e 39 82 40 00 15 0a 32 3b 33 34 33 36 36 32 34 37 82 41 00 03 00 03 00 a2 00 00 00 00 72 01 00 00
DEBUG s7.connection: CreateObject response header: opcode=0x32 function=0x04CA seq=1 session=0x70000CB0 transport=0x36
DEBUG s7.connection: CreateObject response payload: 00 02 87 80 80 99 30 87 80 80 99 31 a1 00 00 01 20 82 1f 01 00 a3 81 69 00 15 13 30 30 3a 31 38 31 42 37 42 30 38 34 37 44 31 31 36 39 34 a3 82 2b 00 04 02 a3 82 2d 00 15 1c 4f 4d 53 50 5f 31 32 2e 30 30 2e 30 33 2e 31 39 5f 33 35 2e 31 39 2e 30 30 2e 30 31 a3 82 2f 10 02 14 8b 03 cd a4 5c 6d 65 ce 18 9c a4 3a a9 4f 43 29 73 1d 91 28 a3 82 32 00 17 00 00 01 3a 82 3b 00 04 86 00 82 3c 00 04 85 40 82 3d 00 04 84 81 84 40 82 3e 00 04 84 81 84 40 82 3f 00 15 1a 31 3b 36 45 53 37 20 35 31 32 2d 31 43 4b 30 31 2d 30 41 42 30 3b 56 32 2e 39 82 40 00 15 0a 32 3b 33 34 33 36 36 32 34 37 82 41 00 03 00 03 00 a2 00 00 00 00 72 01 00 00
DEBUG s7.connection: Session created: id=0x70000CB0 (1879051440), version=V1
INFO s7.connection: ServerSessionVersion captured: 87 bytes
DEBUG s7.connection: === SetupSession === sending (146 bytes): 72 02 00 8a 31 00 00 05 42 00 00 00 02 70 00 0c b0 36 70 00 0c b0 01 01 82 32 01 00 17 00 00 01 3a 82 3b 00 04 86 00 82 3c 00 04 85 40 82 3d 00 04 84 81 84 40 82 3e 00 04 84 81 84 40 82 3f 00 15 1a 31 3b 36 45 53 37 20 35 31 32 2d 31 43 4b 30 31 2d 30 41 42 30 3b 56 32 2e 39 82 40 00 15 0a 32 3b 33 34 33 36 36 32 34 37 82 41 00 03 00 03 00 00 00 00 04 e8 89 69 00 12 00 00 00 00 89 6a 00 13 00 89 6b 00 04 00 00 00 00 00 00 72 02 00 00
DEBUG snap7.connection: Sent 175 bytes: 03 00 00 af 02 f0 80 17 03 03 00 a3 18 0a 38 82 40 54 c0 28 44 6a 90 22 06 79 0a d6 bc d5 65 fd 60 5d 2c 42 c6 ba 24 23 4b 7a 15 28 94 53 58 24 ff bb 1b 2b 7b 4a 7e 5a cb a9 79 b3 b2 d7 58 36 27 63 09 23 ba af db e2 6c 43 96 cb d8 9b 9c 79 17 4a c9 8b e0 34 30 e4 d9 ea 56 71 58 e6 2a 79 d7 f2 9c 1f 27 da a9 70 78 55 8c 90 d0 03 f7 ae 39 bb 56 8c 46 ed 9f 3e 45 1a 6c 5b 07 bb 26 b3 81 41 4a d2 c9 47 4d 89 66 f5 ee a7 20 8f fd 3a 79 8e 92 92 5c 25 5e f7 82 f7 18 d2 b3 0b 47 75 29 60 ef 4f 8c 87 2e ca 07 bf f5 50 08 ed 0a
DEBUG snap7.connection: Received TPKT: version=3 length=54 payload (50 bytes): 02 f0 80 17 03 03 00 2a d7 6e a6 22 60 b1 83 cb ee 59 31 71 19 80 96 6d 6c 2f dc 45 e4 f8 0a 16 bb 2d 4f e9 03 01 a8 75 96 01 bb c4 3d 93 2b d4 81 dd
DEBUG s7.connection: === SetupSession === received (25 bytes): 72 02 00 11 32 00 00 05 42 00 00 00 02 34 00 00 00 00 00 00 00 72 02 00 00
DEBUG s7.connection: SetupSession response: function=0x0542
INFO s7.connection: Session setup completed successfully
INFO s7.connection: V2 IntegrityId tracking enabled
INFO s7.connection: S7CommPlus connected to 192.168.101.34:102, version=V2, session=1879051440, tls=True
INFO s7.client: Connected to 192.168.101.34:102 using S7CommPlus
INFO snap7.client: S7Client initialized (pure Python implementation)
DEBUG snap7.connection: TCP connected to 192.168.101.34:102
DEBUG snap7.connection: Sent COTP Connection Request
DEBUG snap7.connection: Negotiated PDU size: 1024
DEBUG snap7.connection: Unsupported COTP parameter: code=0xc1, length=2
DEBUG snap7.connection: Unsupported COTP parameter: code=0xc2, length=2
DEBUG snap7.connection: Received COTP Connection Confirm
INFO snap7.connection: Connected to 192.168.101.34:102, PDU size: 1024
DEBUG snap7.connection: Sent 25 bytes: 03 00 00 19 02 f0 80 32 01 00 00 00 01 00 08 00 00 f0 00 00 01 00 01 01 e0
DEBUG snap7.connection: Received TPKT: version=3 length=27 payload (23 bytes): 02 f0 80 32 03 00 00 00 01 00 08 00 00 00 00 f0 00 00 01 00 01 01 e0
INFO snap7.client: Negotiated PDU length: 480
INFO snap7.client: [192.168.101.34 R0/S1] Connected to 192.168.101.34:102 rack 0 slot 1
INFO snap7.client: Auto-tuned max_parallel=4 (PDU=480)
INFO s7.client: Legacy S7 connected to 192.168.101.34:102
DEBUG s7.connection:   IntegrityId: read=0
DEBUG s7.connection: === SEND REQUEST === function_code=0x04BB seq=3 session=0x70000CB0
DEBUG s7.connection:   Request header (14 bytes): 31 00 00 04 bb 00 00 00 03 70 00 0c b0 34
DEBUG s7.connection:   IntegrityId (1 bytes): 00
DEBUG s7.connection:   Request payload (19 bytes): 00 00 00 03 00 01 01 00 00 02 81 69 93 59 00 00 00 00 00
DEBUG s7.connection:   Full frame (42 bytes): 72 02 00 22 31 00 00 04 bb 00 00 00 03 70 00 0c b0 34 00 00 00 03 00 01 01 00 00 02 81 69 93 59 00 00 00 00 00 00 72 02 00 00
DEBUG snap7.connection: Sent 71 bytes: 03 00 00 47 02 f0 80 17 03 03 00 3b 3c ca e9 b3 e9 4b 3b 01 7e cb 46 d7 80 50 7b 63 d3 81 a5 ec b5 51 b6 36 4e 5d 9a da b1 93 f8 52 ef 5b 28 52 46 ed 18 08 75 68 ba 6e da 3e fc bb 6f 64 72 4e e4 9f db be 58 f1 52
DEBUG snap7.connection: Received TPKT: version=3 length=1009 payload (1005 bytes): 02 f0 80 17 03 03 03 e5 9f 8b 0e 8e dd a9 a3 0a df 63 ac 81 df 46 99 1c 7c d2 31 3f a0 e2 64 0d 2e fa 12 cc 1d eb f8 5a ee 49 3f c5 ca 49 df 19 f7 a9 75 ee 02 0e cf 81 44 05 0d 05 fd 70 c3 31 fd f4 0f 11 21 72 e8 c0 16 07 1a ea 1d 0b b6 27 b2 0a a9 26 1b 10 b5 c1 4d af fa 51 51 7f 91 31 02 15 66 74 15 c3 42 40 f7 cd 15 3b f6 6d 13 be 01 be 7f ee e5 09 ba 55 1e 2f 81 0f 21 6f da 3d f3 2d 60 6a 52 d2 4f 25 fb 87 72 5c 8b da aa 76 f4 c0 64 b1 51 52 6c 1b cc 79 49 32 24 e7 b3 33 b2 7c c5 7f 06 90 4e 3c 50 d8 e7 b5 0a 03 4d 4d e6 dc 82 39 ec 6b fa 13 73 57 53 3b da ea 02 2b 34 e7 38 a6 e4 51 a0 6e 90 3e 9a 1b 19 98 66 ea 76 05 6b c7 2e e2 7f 45 ba 59 79 b7 dc e0 f1 fc b5 f4 61 ee 61 aa 74 00 36 9c 49 71 ca 19 77 9a f8 b7 3b b2 51 d0 9c 2d d8 21 08 1d 8e c4 af 1a e3 b6 26 5c fd fc ca 55 06 cb 83 66 12 59 19 4a 3b 69 cf 68 73 d1 dd 76 ed 1c b1 e8 5b 17 4b 40 0a 7e 36 3b c9 48 50 ca da ad d9 49 47 d9 d9 3d 1b 8f cc ad 04 fc 57 e5 95 89 e6 c3 75 f3 ad 04 31 fa 00 67 6e 64 51 73 d3 27 64 23 70 8c f8 bd f6 d3 6a 89 46 db 80 86 df d5 fc d5 8c 56 cd 75 54 1c e7 fc 26 62 5a 07 b0 6c 61 36 f2 97 e1 b6 54 05 7a bb 66 09 d6 c1 be c4 4a 57 82 67 a3 91 88 45 aa 4b 8c 5b c0 51 3b eb a0 e7 fe 83 6d 93 7f 94 b0 9e 4d 49 61 0d ef 20 e2 03 5f 84 ea ff 38 06 1a 9c 5f c8 8f 99 6d 29 37 17 82 ea f8 34 da 92 f9 05 6e 90 7e 91 72 08 f3 53 a1 ed fc a1 36 d8 3c 25 c3 c3 bc aa df 2c ec 11 13 13 43 d7 12 55 36 26 89 8b 19 50 74 59 6d 0c c0 35 53 cc 86 d8 65 ca 31 75 7c 9b 66 b2 49 9c e1 8c d7 7c a3 60 86 3e 75 9c 5d 22 3b 11 59 00 45 58 34 0e 07 26 e2 f8 ce 6d e7 1e 34 45 55 09 b3 9d d4 7c 99 b3 6a 1a 23 e7 91 23 d7 88 73 44 d1 b1 c2 a7 07 fb 07 68 6b 2d e4 b3 11 b7 d2 ed 70 3e 6f cc ae 16 1d f1 0b e4 fd 1e de c4 a4 7d 7e 7d d6 a6 d7 06 85 5d 56 8d 7f 07 d8 88 d5 c9 92 93 ec 6c 90 59 42 eb 82 cb 76 8f 36 03 ca 1b 7e 91 08 70 a3 08 2a a0 1d 18 fe 27 c7 4c 3b fa fb c3 cf c0 a0 13 ec 4c 29 f0 36 7a f7 ce fa 9c 53 c6 c4 02 ee fb 3f 9d bc a3 db a8 96 97 94 80 fa fc 6a d5 4e 98 82 a6 0e 74 15 5d 8a e2 2c a4 65 f3 89 f5 e1 47 04 1d ac 18 33 0f 58 84 6d 75 cd 55 b0 7c 95 9f 19 03 55 c5 b8 ca 4a 0f 64 e3 dc 2b 39 95 58 ab 20 11 12 a3 08 4f 3d cd 4e ce 5f 2f f0 c2 c2 6b 07 d4 4a 64 88 9d 85 3e c8 6f ee 85 36 6b 44 28 8e 46 68 a1 3d 1d 8f 78 5e ae bb 28 8f 96 2c 67 89 40 5d 3e e2 7c 67 02 4e 44 d4 6c 8d f0 fc 0d fe bd fa de d7 df 48 33 b1 ab 8a 6c 51 41 b2 45 ac 0d c2 c7 ce 41 e1 ae 0b 7d 9a 5d 2d 2d c6 d8 f9 5a 9b c7 d4 83 86 a1 13 b3 8c 5a ec d3 33 cc 4c 8f 7e 08 1d 44 9e 61 8b 5b ee 76 ee 41 e5 03 58 fc 26 1f e2 7a ad 6e d9 6b 1b da da 1e 0d 41 07 ce 7a 63 03 69 c6 21 23 0d 2a 5b 28 f8 7a 59 fa 1a 0c 8b 35 49 09 c1 45 15 9e c2 00 eb 5a 8c 1c c3 95 87 2e b0 88 7a 53 34 c2 45 62 f4 d3 bd 1e 74 8d 10 a2 cc 61 51 75 bb 0e 30 64 8a d2 2f 85 03 41 74 80 4b 4f dc df 81 ce 2c e7 70 63 55 5e 94 0f 3a 32 ee 4d 8b 33 60 4f c0 6c 69 68 e0 78 f1 eb fa 12 da 35 26 76 87 8c 8c cc 26 f1 8a d0 cb f8 b8 ce e8 e6 2c 81 a3 67 80 6f 82 26 f2 fc 75 7e 49 5f 2f 68 6f a6 fd 49 90 2f 60 57 0b 8b 8b 24 90 b2 cd d6 50 46 37 76
...

Found 20733 variables
DEBUG snap7.connection: Received TPKT: version=3 length=220 payload (216 bytes): 02 f0 80 17 03 03 00 d0 65 c5 4c 04 6d 93 26 4a ae 40 5d ef 36 26 0d d2 57 84 a5 30 28 8e be 2e 5d 3c 0c a1 df 6d 93 96 f1 d6 fc 87 9b 39 87 e2 0e 7b 7d 0f 7b a7 f8 38 98 60 dd 37 b7 59 40 10 8c 0e 61 87 c1 f3 c4 b8 c6 19 97 3a ba 80 94 dc d5 da 4b 88 cc 47 e1 b4 13 b5 24 86 70 de 1e 52 b0 69 c6 b1 00 ab 55 d9 45 ab 04 26 d9 43 7f 69 4d 88 d7 75 2e ae 57 71 fa e1 48 f6 a4 85 b0 d1 2e 1b 05 bd 5a 79 00 ce dc 0f a4 6e 4e 42 eb 5e 16 46 79 ec 68 b5 a6 95 af 8a 6a 49 59 72 2c 83 82 26 20 c2 7e a9 ca ab 99 a5 50 ff 03 1a 8a 5b c0 40 32 2d 8c 92 5e e3 bd 90 3d f5 22 7c 4a 70 c6 2b 21 22 c3 01 fc a0 d5 17 12 59 fb 2b c3 e2 3f 4a 26 1f 45 2d 2a 41
INFO snap7.connection: Disconnected from 192.168.101.34:102
INFO snap7.connection: Disconnected from 192.168.101.34:102
INFO snap7.client: Disconnected from 192.168.101.34:102
INFO snap7.client: Disconnected from 192.168.101.34:102

[EliTheCoder]

Confirming this works on a second CPU model. Tested the sync path (a5a7508) against a 6ES7 515-2TM01-0AB0, FW V2.9 over TLS — same firmware band as @bvanelli's 1512, different CPU:

ServerSessionVersion captured: 88 bytes
Session setup completed successfully
S7CommPlus connected ..., version=V2, session=..., tls=True
protocol: Protocol.S7COMMPLUS
Found 5144 variable(s)

Browse returned 5144 tags with correct names/types/offsets (data_type, opt_address/nonopt_address all populated). So the 14→10 header fix + with_integrity=False combo works on the 1515-2TM too, sync client included.

Two notes for whoever picks up the follow-ups:

1. export_keying_material isn't a per-environment issue — it can't work on stdlib ssl at all. CPython's ssl module never wrapped SSL_export_keying_material, so hasattr(ssl.SSLSocket, "export_keying_material") is False on any stock build (mine: Python 3.11.13, OpenSSL 3.0.13). The OMS-exporter-secret warning will fire for everyone; browse works anyway because it doesn't depend on legitimation. Wiring up the OMS/legitimation path will need a TLS backend that exposes the exporter (pyOpenSSL / cryptography FFI), not just a newer OpenSSL.

2. Re: the IntegrityId increment TODO — happy to help test once someone implements it. Browsing 5144 symbols completed fine without it, but I haven't exercised anything that needs the incrementing counter yet.