ISKRA MT174
ISKRA MT174 (230/400V, rated 85A) mostly used in Saxonia this seems to have some noticable semaphores wich can be visualy inspected:
KD = lid/cover open (there must be a switch somewhere) BAT = internal battery low DÜ = transmission mode FF = "Fatal" counter (?) SET = counter in program mode
The IR-Interface is claimed to be IEC 62056-21 mode C (asynchron, half-duplex, 300 - 19.200 baud, 7bit, even parity, 1stop (1_7D_1P_E_1S) and it is bidirectional. So one can also send something over that interface. There's an optional RS485 wire interface on some models.
The "Fatal counter" is a hex value 8bit flag register:
0 = Firmware error 1 = Counter parameter checksum error 2 = energy/maximum checksum error 3 = not used 4 = not used 5 = not used 6 = maintenance warning level (?) 7 = not used
