hey philipp!
thank you for pointing me in this directions.
first, this is swichting 13 lights with eltakobus.serial on debug:
2024-01-27 08:36:31.901 DEBUG (SyncWorker_5) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 0b, data 01 00 00 09, status = 0x00> - Serialized: a55a6b07010000090010000b0097
2024-01-27 08:36:31.902 DEBUG (SyncWorker_0) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 1a, data 01 00 00 09, status = 0x00> - Serialized: a55a6b07010000090010001a00a6
2024-01-27 08:36:31.902 DEBUG (SyncWorker_0) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 10, data 01 00 00 09, status = 0x00> - Serialized: a55a6b070100000900100010009c
2024-01-27 08:36:31.902 DEBUG (SyncWorker_0) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 19, data 01 00 00 09, status = 0x00> - Serialized: a55a6b07010000090010001900a5
2024-01-27 08:36:31.902 DEBUG (SyncWorker_0) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 07, data 02 64 00 09, status = 0x00> - Serialized: a55a6b07026400090010000700f8
2024-01-27 08:36:31.902 DEBUG (SyncWorker_0) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 11, data 01 00 00 09, status = 0x00> - Serialized: a55a6b070100000900100011009d
2024-01-27 08:36:31.902 DEBUG (SyncWorker_0) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 12, data 01 00 00 09, status = 0x00> - Serialized: a55a6b070100000900100012009e
2024-01-27 08:36:31.903 DEBUG (SyncWorker_0) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 17, data 01 00 00 09, status = 0x00> - Serialized: a55a6b07010000090010001700a3
2024-01-27 08:36:31.903 DEBUG (SyncWorker_0) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 08, data 02 64 00 09, status = 0x00> - Serialized: a55a6b07026400090010000800f9
2024-01-27 08:36:31.903 DEBUG (SyncWorker_0) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 0f, data 01 00 00 09, status = 0x00> - Serialized: a55a6b07010000090010000f009b
2024-01-27 08:36:31.903 DEBUG (SyncWorker_0) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 0c, data 01 00 00 09, status = 0x00> - Serialized: a55a6b07010000090010000c0098
2024-01-27 08:36:31.903 DEBUG (SyncWorker_0) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 18, data 01 00 00 09, status = 0x00> - Serialized: a55a6b07010000090010001800a4
2024-01-27 08:36:31.906 DEBUG (SyncWorker_21) [eltako] [Gateway] [Id: 1] Send message: <Regular4BSMessage from 00 10 00 06, data 02 64 00 09, status = 0x00> - Serialized: a55a6b07026400090010000600f7
2024-01-27 08:36:31.907 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 0b, data 01 00 00 09, status = 0x00>
2024-01-27 08:36:31.909 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 1a, data 01 00 00 09, status = 0x00>
2024-01-27 08:36:31.910 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 10, data 01 00 00 09, status = 0x00>
2024-01-27 08:36:31.912 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 19, data 01 00 00 09, status = 0x00>
2024-01-27 08:36:31.913 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 07, data 02 64 00 09, status = 0x00>
2024-01-27 08:36:31.915 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 11, data 01 00 00 09, status = 0x00>
2024-01-27 08:36:31.916 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 12, data 01 00 00 09, status = 0x00>
2024-01-27 08:36:31.918 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 17, data 01 00 00 09, status = 0x00>
2024-01-27 08:36:31.920 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 08, data 02 64 00 09, status = 0x00>
2024-01-27 08:36:31.921 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 0f, data 01 00 00 09, status = 0x00>
2024-01-27 08:36:31.923 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 0c, data 01 00 00 09, status = 0x00>
2024-01-27 08:36:31.924 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 18, data 01 00 00 09, status = 0x00>
2024-01-27 08:36:31.927 DEBUG (Thread-3) [eltakobus.serial] Sent message: <Regular4BSMessage from 00 10 00 06, data 02 64 00 09, status = 0x00>
2024-01-27 08:36:32.244 DEBUG (Thread-3) [eltako] [Gateway] [Id: 1] Received message: <EltakoWrappedRPS from 00 00 00 18, status 30, data 70>
2024-01-27 08:36:35.104 DEBUG (Thread-3) [eltako] [Gateway] [Id: 1] Received message: <EltakoWrapped4BS from 00 00 00 06, status 00, data 02 64 00 09>
So now what i found…you pointed me towards line 118 in this file: https://github.com/grimmpp/eltako14bus/blob/8a65376e32f56f7cfc17125b670782e91750e3cb/eltakobus/serial.py#L118C9-L118C51
So i thought that line 119 might be the one to tweak in order to make it a bit slower. So i tried…i changed line 119 from
time.sleep(.001)
to
time.sleep(.01)
and the problem is gone. i can now switch a group of 13 lights just fine.