Mitsubishi Electric Melsec A Series - Page 174

REPLACEMENT OF THE MELSECNET/10 (REMOTE I/O NETWORK)
5 - 8
5
4) Performance comparison of AJ71LR21/A1SJ71LR21/AJ71QLR21/A1SJ71QLR21 and
QJ71BR11
: Compatible, : Partial change required, × : Incompatible
Item
Specifications
Compatibility Precautions for replacement
AJ71LR21
A1SJ71LR21
AJ71QLR21
A1SJ71QLR21
QJ71BR11
Maximum number
of link points per
network
LX/LY 8192 points
LB 8192 points
16384 points
*1
LW 8192 points
16384 points
*1
Maximum number of link
points per station
<Remote master
station  remote I/O
station>
{(LY + LB) 8 + (2 ×
LW)} 1600 bytes
<Remote I/O station
 remote master
station>
{(LY + LB) 8 + (2 ×
LW)} 1600 bytes
<Remote master station  remote I/O station>
*2
{(LY + LB) 8 + (2 × LW)} 1600 bytes
<Remote I/O station  remote master station>
*2
{(LY + LB) 8 + (2 × LW)} 1600 bytes
<Multiplexed remote master station  multiplexed
remote sub-master station>
{(LY + LB)  8 + (2 × LW)} 2000 bytes
Communication speed 10Mbps
Communication method Token ring method Token bus method
Nothing to be noted though the
communication method differs.
Synchronous type Frame synchronization method
Encoding method Manchester code
Transmission method Duplex loop Single bus
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.
Transmission format HDLC standards (frame format)
Maximum number of
networks
255 (Total number of
PLC to PLC networks
and remote I/O
networks)
239 (Total number of PLC to PLC networks and
remote I/O networks)
Network No.240 to No.250 cannot
be set.
Alternate them with unused
network No.
Number of stations connected
in one network
65 stations (Remote master station: 1, remote
I/O station: 64)
33 stations (Remote master
station: 1, remote I/O station:
32)
*3
Normal stations up to 32 stations
can be used on a coaxial bus
system. To use 33 normal stations
or more, using an optical loop
system is recommended.
Applicable cable 3C-2V, 5C-2V, 5C-FB
Overall distance
3C-2V: 19.2km
5C-2V, 5C-FB: 30km
3C-2V: 300m
5C-2V, 5C-FB: 500m
Either use an A6BR10/A6BR10-
DC type repeater unit, or use an
optical loop system.
Distance between stations
3C-2V: 300m
5C-2V, 5C-FB: 500m
Error control system
CRC(X
16
+ X
12
+ X
5
+ 1) and retry by a time over
RAS function
• Loop-back function due to error detection or
broken cable
• Diagnostic function for checking local link
lines
• Abnormal detection using link special relays
and link special registers
• Network monitoring and various diagnostic
functions
• Diagnostic function for
checking local link lines
• Abnormal detection using
link special relays and link
special registers
• Network monitoring and
various diagnostic
functions
The loopback function cannot be
used on a coaxial bus system. To
use the loopback function, using
an optical loop system is
recommended.
Transient transmission
• Monitor, program up/download with
peripheral device
• Dedicated link instruction
• Available for Intelligent function module
(only AJ71QLR21/A1SJ71QLR21)
• 1:1 communication
(Monitor, program up/
download)
• Dedicated link instruction
For comparison of dedicated link
instruction, refer to Section 5.1.7.
Number of occupied I/O
points
32 points per slot (I/O assignment: special 32
points)
32 points per slot (I/O
assignment: intelli. 32 points)