CRC error, start block occasionally corrupted

[janneojala]

Most of the time I am getting no readings from Aidan 7534 due crc errors, occasionally readings are published correctly.

It seams that start block is corrupted:

11:44:59	[D]	[data:270]	��9� 7534
11:44:59	[D]	[data:270]	
11:44:59	[D]	[data:270]	0-0:1.0.0(240124114500W)
11:44:59	[D]	[data:270]	1-0:1.8.0(00009491.279*kWh)
11:44:59	[D]	[data:270]	1-0:2.8.0(00000000.000*kWh)
11:44:59	[D]	[data:270]	1-0:3.8.0(00000177.088*kVArh)
11:44:59	[D]	[data:270]	1-0:4.8.0(00000513.777*kVArh)
11:45:00	[D]	[data:270]	1-0:1.7.0(0003.232*kW)
11:45:00	[D]	[data:270]	1-0:2.7.0(0000.000*kW)
11:45:00	[D]	[data:270]	1-0:3.7.0(0000.000*kVAr)
11:45:00	[D]	[data:270]	1-0:4.7.0(0000.664*kVAr)
11:45:00	[D]	[data:270]	1-0:21.7.0(0001.568*kW)
11:45:00	[D]	[data:270]	1-0:22.7.0(0000.000*kW)
11:45:00	[D]	[data:270]	1-0:41.7.0(0000.013*kW)
11:45:00	[D]	[data:270]	1-0:42.7.0(0000.000*kW)
11:45:00	[D]	[data:270]	1-0:61.7.0(0001.621*kW)
11:45:00	[D]	[data:270]	1-0:62.7.0(0000.000*kW)
11:45:00	[D]	[data:270]	1-0:23.7.0(0000.000*kVAr)
11:45:00	[D]	[data:270]	1-0:24.7.0(0000.474*kVAr)
11:45:00	[D]	[data:270]	1-0:43.7.0(0000.000*kVAr)
11:45:00	[D]	[data:270]	1-0:44.7.0(0000.114*kVAr)
11:45:00	[D]	[data:270]	1-0:63.7.0(0000.000*kVAr)
11:45:00	[D]	[data:270]	1-0:64.7.0(0000.000*kVAr)
11:45:00	[D]	[data:270]	1-0:32.7.0(233.6*V)
11:45:00	[D]	[data:270]	1-0:52.7.0(233.6*V)
11:45:00	[D]	[data:270]	1-0:72.7.0(234.6*V)
11:45:00	[D]	[data:270]	1-0:31.7.0(007.1*A)
11:45:00	[D]	[data:270]	1-0:51.7.0(000.4*A)
11:45:00	[D]	[data:270]	1-0:71.7.0(006.8*A)
11:45:00	[D]	[data:270]	!9ABA
11:45:00	[I]	[crc:281]	Telegram read. CRC: 27B5 = 9ABA. PASS = NO

When reading succeeds, start block is correctly "/ADN9 7534"

11:46:19	[D]	[data:270]	/ADN9 7534
11:46:19	[D]	[data:270]	
11:46:19	[D]	[data:270]	0-0:1.0.0(240124114620W)
11:46:19	[D]	[data:270]	1-0:1.8.0(00009491.398*kWh)
11:46:19	[D]	[data:270]	1-0:2.8.0(00000000.000*kWh)
11:46:19	[D]	[data:270]	1-0:3.8.0(00000177.088*kVArh)
11:46:19	[D]	[data:270]	1-0:4.8.0(00000513.784*kVArh)
11:46:20	[D]	[data:270]	1-0:1.7.0(0003.209*kW)
11:46:20	[D]	[data:270]	1-0:2.7.0(0000.000*kW)
11:46:20	[D]	[data:270]	1-0:3.7.0(0000.000*kVAr)
11:46:20	[D]	[data:270]	1-0:4.7.0(0000.691*kVAr)
11:46:20	[D]	[data:270]	1-0:21.7.0(0001.575*kW)
11:46:20	[D]	[data:270]	1-0:22.7.0(0000.000*kW)
11:46:20	[D]	[data:270]	1-0:41.7.0(0000.014*kW)
11:46:20	[D]	[data:270]	1-0:42.7.0(0000.000*kW)
11:46:20	[D]	[data:270]	1-0:61.7.0(0001.620*kW)
11:46:20	[D]	[data:270]	1-0:62.7.0(0000.000*kW)
11:46:20	[D]	[data:270]	1-0:23.7.0(0000.000*kVAr)
11:46:20	[D]	[data:270]	1-0:24.7.0(0000.484*kVAr)
11:46:20	[D]	[data:270]	1-0:43.7.0(0000.000*kVAr)
11:46:20	[D]	[data:270]	1-0:44.7.0(0000.113*kVAr)
11:46:20	[D]	[data:270]	1-0:63.7.0(0000.000*kVAr)
11:46:20	[D]	[data:270]	1-0:64.7.0(0000.065*kVAr)
11:46:20	[D]	[data:270]	1-0:32.7.0(233.7*V)
11:46:20	[D]	[data:270]	1-0:52.7.0(233.4*V)
11:46:20	[D]	[data:270]	1-0:72.7.0(234.6*V)
11:46:20	[D]	[data:270]	1-0:31.7.0(007.0*A)
11:46:20	[D]	[data:270]	1-0:51.7.0(000.4*A)
11:46:20	[D]	[data:270]	1-0:71.7.0(006.8*A)
11:46:20	[D]	[data:270]	!D76F
11:46:20	[I]	[crc:281]	Telegram read. CRC: D76F = D76F. PASS = YES

Any ideas what might cause this?