Mitsubishi L26CPU-BT, User Manual

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App - 43 App - 43
APPENDIXES
(2) For remote I/O net mode
LS = BT {27 + (NI 4.8) + (N 30) + (ni 4.8)} + ST + RT + F [
μ
s]
BT: Constant (transmission speed)
Transmission speed 156 kbps 625 kbps 2.5 Mbps 5 Mbps 10 Mbps
BT 51.2 12.8 3.2 1.6 0.8
NI: NI: Final station number (must be a multiple of 8)
Final station number 1 to 8 9 to 16 17 to 24 25 to 32 33 to 40 41 to 48 49 to 56 57 to 64
NI 8 16 24 32 40 48 56 64
N: Number of connected modules
ni:
Total number of occupied stations
ST: Constant
250 + (ni 10)
RT: Retry processing time (only link scans whose slave stations became
abnormal are added)
α + β (number of stations with communication error detected – 1)
α : Retry processing time on the first station
BT (778.5 + R 3)
R: 13.2 + (NI 4.8)
β : Retry processing time on the second and subsequent stations
BT (778.5 + P 3)
P: 10.8
F : Return processing time (only stations with communication errors are
added)
BT 243.1 + ST
(Example) Using the following system configuration when the transmission speed
is 10 Mbps (assuming that there is no faulty station or retry)
1: (occupies 1 station)
Station
number 1
Station
number 2
Station
number 3
Master
station
Remote
I/O station
Remote
I/O station
Remote
I/O station
1 1 1
BT = 0.8 ST = 250 + (ni 10)
NI = 3 8 = 250 + (3 10)
N = 3 = 280
ni = 3
LS = 0.8 {27 + (8 4.8) + (3 30) + (3 4.8)} + 280
= 415.84 [
μ
s]
= 0.42 [ms]