Mitsubishi Electric Melsec A Series - Page 116

REPLACEMENT OF MELSECNET (II) AND /B (REMOTE I/O NETWORK)
3 - 4
3
(b) Modules for GI optical cable
: Compatible, : Partial change required, × : Incompatible
Item
Specifications
Compat-
ibility
Precautions for replacementMELSECNET (II) module MELSECNET/H module
Optical loop Optical loop(QJ71LP21G, QJ72LP25G)
Maximum
number of
link points
per
network
X/Y
Max. 2048 points and max. number of
I/O points of CPU module on master
station
8192 points
B-
16384 points
(Remote master station  remote I/O
station: 8192 points,
remote I/O station  remote master
station: 8192 points)
W
• (MELSECNET mode) 1024 points
• (MELSECNET II composite mode)
4096 points
16384 points
(Remote master station  remote I/O
station: 8192 points,
remote I/O station  remote master
station: 8192 points)
Maximum
number of
link points
per
station
Master
station
• (MELSECNET mode) 1024 bytes
• (MELSECNET II composite mode)
link parameter First half: 1024 bytes
link parameter Second half: 1024 bytes
Remote master station  remote I/O
station
{(LY + LB)  8 + (2 × LW)} 1600 bytes
Remote
I/O
station
512 bytes
Remote I/O station  remote master
station
{(LX + LB)  8 + (2 × LW)} 1600 bytes
Maximum number of
I/O points per station
512 points 4096 points
Communication
speed
1.25 Mbps 10 Mbps
Number of stations
connected in one
network
65 stations (Master station: 1, local
station + remote I/O station: 64)
65 stations (Remote master station: 1,
remote I/O station: 64)
Set the PLC to PLC network to
a separate network.
Applicable cable GI optical cable GI optical cable
Overall distance 10 km 30 km
Distance between
stations
GI optical cable: 2km GI optical cable: 2km
Maximum number of
networks
-239
New MELSECNET/H
parameter (mandatory)
Communication
method
Half duplex bit serial method Token ring method
Nothing to be noted though the
communication method differs.
Transmission
method
Duplex loop
Modulation method
(Encoding method)
(Modulation method) CMI method (Encoding method) NRZI coding
Nothing to be noted though the
modulation method differs.
Transmission format HDLC standards (frame format)
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
Number of occupied
I/O points
(Master station)
CPU integrated type: 0 point
Standalone:32 points per slot (I/O
assignment: special 32 points)
(Master station)
32 points per slot (I/O assignment: intelli.
32 points)
When the master station is
replaced from a CPU
integrated type, one new slot
(32 points) is required.