5
(2) Performance specifications of MELSECNET data link system and
A1SJ71AR23Q
Table 2.2 Performance specifications of MELSECNET data link system and A1SJ71AR23Q
Item
Specifications
MELSECNET data link system
MELSECNET
mode
MELSECNET II
mode
MELSECNET II
composite mode
Maximum
applicable link
points per
station
Input (X)
Up to the maximum number of I/O points for the CPU module
used in the master station is applicable.
(The total number of link points for slave station is equal to the
number of link using points for the master station)
Output (Y)
Maximum link
points in a
system
B
1024 points
(128 byte)
4096 points (512 byte)
W
1024 points
(2048 byte)
4096 points (8192 byte)
Maximum link
points per
station
Master
station
1024 byte
1024 byte (First half of link parameters)
1024 byte (Latter half of link parameters)
Local station
Remote I/O
station
512 byte
Number of I/O
points: 512 points
-
512 byte
Number of I/O
points: 512 points
Communication speed
1.25Mbps
Communication method
Half duplex bit serial method
Synchronization method
Frame synchronization method
Transmission path
Duplex loop
Overall cable distance
Up to 10km (Station-to-station 500m)
Number of connected
stations
Up to 65 (Master station: 1, The total number of local stations
and remote I/O stations: 64)
Modulation method
CMI method
Transmission format
Conforming to HDLC (Frame format)
Error control system
Retries due to CRC (generating polynomial X
16
+X
12
+X
5
+1) and
time out
RAS function
• Loopback function due to error detection and cable break
• Diagnostic function including link line check of host station
etc.
