Data Link Processing Time; Link Scan Time - Mitsubishi MELSEC-Q Series User Manual

5 DATA LINK PROCESSING TIME

5 DATA LINK PROCESSING TIME
This chapter explains the data link processing time such as the link scan time and
transmission delay time.

5.1 Link Scan Time

This section explains the CC-Link scan time. The following describes the method for
calculating the normal value and maximum value for the remote net mode or remote
I/O net mode.
[Link scan time (LS)]
(1) For remote net mode
Final station number
5 - 1
LS = BT {27 + (NI 4.8) + (NW
ST + F + TR (µ s)
BT: Constant (transmission rate)
Transmission rate 156 kbps 625 kbps 2.5 Mbps 5 Mbps
BT 51.2
NI: The final station number in a, b and c
(It includes the number of dedicated stations but excludes the
reserved stations, and must be a multiple of 8.)
a: Total number of stations occupied for remote I/O stations
b: Total number of stations occupied for remote device stations
c: Total number of stations occupied for local stations, standby
master station and intelligent device stations
NW: The final station number in b and c
(Includes the number of dedicated stations but excludes the reserved
stations, and must be a multiple of 8.)
1 to 8
NI, NW 8
N: Number of connected stations (excluding reserved stations)
ni: a + b + c (excluding reserved stations)
nw: b + c (excluding reserved stations)
ST: Constant
A: Last station number of remote I/O stations
B: Last station number of remote device stations (including the
number of occupied stations)
C: Last station number of local, standby master and intelligent device
stations (including the number of occupied stations)
(The largest value found in 1) to 3) below. However, 2) is disregarded
when B = 0 and 3) is disregarded when C = 0)
1) 800 + (A
2) 900 + (B
3) For C ≤ 26 : 1200 + (C
For C > 26 : 3700 + {(C - 26)
F: Return processing time {only when there is a faulty station (including
error invalid and temporary error invalid stations)}
Number of faulty stations
9.6) + (N 30) + (ni
12.8 3.2 1.6
9 to 16 17 to 24 25 to 32 33 to 40 41 to 48 49 to 56 57 to 64
16 24 32
15)
50)
100)
25}
118 BT
MELSEC-Q
4.8) + (nw 9.6)} +
10 Mbps
0.8
40 48 56 64
(1 + number of retries)
5 - 1
5