Number Of Connectable Slaves - Mitsubishi A1SJ71PB92D User Manual

3. SPECIFICATIONS
3.3.3

Number of connectable slaves

Please calculate the number of the slave which can be connected under the following
(1) and (2) conditions.
(1) Restrictions on maximum data length of slave station error
information
The maximum data length of the slave station error information that the
AJ71PB92D/A1SJ71PB92D can receive varies with the minimum station number
and maximum station number of the slave stations set in the parameters, and can
be calculated using the following expression.
Maximum data length of acceptable error information [bytes] = Min
N = Min((a - b + 1)
a: Maximum station number of slave station
b: Minimum station number of slave station
: Min(a, b) = A or B, whichever is smaller
If the maximum data length (Max_Diag_Data_Len) of the error information
described in the GSD file of a slave station is greater than the value calculated by
the above expression, normal communication may not be made with that slave
station.
If normal communication cannot be made, try the following methods:
(a) Set the station numbers of the slave stations with no unused numbers in
between.
(b) Make setting on the slave station side to shorten the maximum data length of
the error information. (If possible)
(c) Using two or more AJ71PB92D/A1SJ71PB92D, reduce the number of slave
stations per module.
(2) Restrictions on parameter data length of slave station
The parameter size which can be set in AJ71PB92D/A1SJ71PB92D should meet
the following formula.
Note that the system construction which does not meet the following formula
causes the error of 1302
n
5 + (number of parameter blocks of each slave station)
i = 1
n = number of slave stations
(number of parameter blocks of each slave station) = sum total of the numbers of parameter
5, 300)
.
H
blocks calculated by each slave station
3-8
MELSEC-A
12600
, 244
N - 10
128