Sharp JW-20CM - Manual (Page 41)

8 · 3
8-2 Data transfer required time and communication timing
(1) Required time for data transfer
Time required for a master station to communicate with all the slave stations is determined by number
of connected stations and number of points of all slave stations, as well as number of data bytes of
JW model special I/O modules.
N : Total number of data bytes of all the slave station’s I/O model and JW model special I/O
modules (value to be calculated by number of bytes 8 points)
P : Number of slave stations
136 : Use 136 bits for station address on the communication format and error check function.
1250 : Baud rate; 1.25 M bit/sec.
1.4P + 5.3 : Data processing time of the master station
2.5 : Total sequential send processing of the communication stations.
α : Communication time at executing remote program/remote monitor.
T = + 1.4P + 5.3 + 2.5 (P + 1) + α [ms]
(N + 136 x P) x 2
1250
· If "synchronous" is selected, one scan cycle time of a PC will vary with change of transfer
required time.
· Number of data bytes on the JW model special I/O module is a value set in parameter
address 000600 to 000777
(8)
on the master station.
Remarks