Mitsubishi Electric MELSEC-A Series Manual page 146

4
REPLACEMENT OF THE MELSECNET/10 (PLC TO PLC NETWORK)
(4) Performance comparison of AJ71LR21/A1SJ71LR21/AJ71QLR21/A1SJ71QLR21 and
QJ71BR11 (MELSECNET/10 mode)
Item
A1SJ71LR21
Maximum
LX/LY 8192 points
number of link
LB 8192 points
points per
LW 8192 points
network
Maximum number of link
{(LY + LB)  8 + (2 × LW)}
points per station
Communication speed 10Mbps
Communication method Token ring method
Synchronous type Frame synchronization method
Encoding method Manchester code
Transmission method Duplex loop
Transmission format HDLC standards (frame format)
255 (Total number
of PLC to PLC
Maximum number of
networks and
networks
remote I/O
networks)
Maximum number of
9
groups
Number of stations 64 stations (Control station: 1, normal
connected in one network station: 63)
Applicable cable 3C-2V, 5C-2V, 5C-FB
3C-2V: 19.2km
Overall distance
5C-2V, 5C-FB: 30km
Distance between 3C-2V: 300m
stations 5C-2V, 5C-FB: 500m
Error control system
CRC(X
4
- 5
Specifications
AJ71LR21 AJ71QLR21
A1SJ71QLR21
2000 bytes
239 (Total number of PLC to PLC networks
and remote I/O networks)
16 12 5
+ X + X + 1) and retry by a time over
: Compatible,
Compatibility
QJ71BR11
(MELSECNET/10 mode)
Token bus method
Single bus
32 stations (Control
station: 1, normal station:
31)
3C-2V: 300m
5C-2V, 5C-FB: 500m
: Partial change required, ×: Incompatible
Precautions for replacement
Nothing to be noted though
the communication method
differs.
The loopback function and
multiplex transmission
function cannot be used on a
coaxial bus system. To use
the functions, using an optical
loop system is recommended.
Network No.240 to No.250
cannot be set.
Alternate them with unused
network No.
Normal stations up to 31
stations can be used on a
coaxial bus system. To use 32
normal stations or more, using
an optical loop system is
recommended.
Either use an A6BR10/
A6BR10-DC type repeater
unit, or use an optical loop
system.