Allen Bradley DF1
The registter's address format: N7:1.2/3
N - Type of data file, such types are available: I, O, S, B, T, C, R, N, F
7 - number of data file (optional for types - I, O, S)
1 - element number
2 - sub-element number (optional)
3 - bit number (optional, does not work with bit - type)