Link Scan Time; Precaution - Mitsubishi A1SJ61BT11 User Manual

15 FUNCTIONS (FUNCTION VERSION B OR LATER)

15.7.4 Link scan time

LS s
: In remote net mode (theoretical value)
: In remote I/O net mode (theoretical value)
4000
3000
2000
1000
0

15.7.5 Precaution

When the remote I/O net mode is used, the link scan time (LS) is given by the following
expression.
LS = BT {25.0 + (NI × 4.0) + (N × 28.0) + (ni × 4.0)} + ST
+ { Number of communication faulty stations × 48 × BT × Number of retries} [µs]
BT : Constant (transmission speed)
Transmission speed
BT
NI : Last station number (shall be the multiple of 8)
N : Number of connected modules
ni : Total number of occupied stations
ST : Constant
ST = 200 + (ni × 20)
: Only when there is a communication faulty station.
A difference in link scan time between the operations in the remote I/O net mode and
the remote net mode (conventional mode) is shown below.
10 20
Figure 15.4 Link scan time
Set the remote I/O station number sequentially. Otherwise the unset station will be
detected as an error, thus affecting the link scan time.
156kbps 625kbps
51.2 12.8
30 40
15 - 13
MELSEC-A
2.5Mbps 5Mbps
3.2 1.6
50 60
Number of remote I/O stations station
10Mbps
0.8
64