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4 FUNCTIONS
MELSEC-QnA
4.7 Error Invalid Station Function
This is a function to treat the remote and local stations that cannot perform data links
due to power off, etc. not as "data-link faulty stations" on the master station and the
local station.
Be careful, however, for errors will not be detected at all if set so.
POINT
If the remote or local station set as the invalid station and also "specified as a reserved
station", the reserved station function has priority.
(1) Setting method
The invalid station specification is performed with parameters (buffer memory
address 14
H to 17H).
Turn on the bit corresponding to the station number to be set as invalid.
However, for the remote/local station which occupies more than 2 stations, turn
on the only bit corresponding to the station number set with the module's station
number setting switch.
The buffer memory configuration is shown below. (1 to 64 indicates station
numbers.)
Address b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
14
H 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
15H 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17
16H 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33
17H 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
(2) Setting example
(a) System configuration example
When specifying the remote station No.3 and local station No.7 as invalid
stations in a system where three remote and two local stations are
connected:
Master
station
Station No. 1
Remote station
(occupies 2 stations)
Station No. 3
Remote station
(occupies 1 station)
Local station
(occupies 1
station)
Station No. 5
Remote station
(occupies 2 stations)
Station No. 4
Modules to be set as error invalid
Local station
(occupies 4
stations)
Station No. 7
(b) Buffer memory setting example
Turn on the 2nd bit, corresponding to station No. 3, and 6th bit,
corresponding to station No. 7. (Set "68" for address 14
H.)
Address b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
14
H 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0
15H 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
16H 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
17H 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0