Performance Specifications Comparisons; Module Performance Compatibility Comparisons - Mitsubishi Electric MELSEC-A Series Manual

3
REPLACEMENT OF MELSECNET (II) AND /B (REMOTE I/O NETWORK)

3.2 Performance Specifications Comparisons

3.2.1 Module performance Compatibility comparisons

(1) Comparison between MELSECNET (II) module (optical loop) and MELSECNET/H module
(optical loop)
(a) SI optical cable, H-PCF optical cable
Item
Max. 2048 points and max. number of
X/Y I/O points of CPU module on master
station
Maximum
number of
B
link points
per
network
• (MELSECNET mode) 1024 points
W • (MELSECNET II composite mode)
• (MELSECNET mode) 1024 bytes
Master
Maximum
• (MELSECNET II composite mode)
station
number of
link points
Remote
per
I/O 512 bytes
station
station
Maximum number of
512 points
I/O points per station
Communication
1.25 Mbps
speed
Number of stations
65 stations (Master station: 1, local
connected in one
station + remote I/O station: 64)
network
SI optical cable
Applicable cable
H-PCF optical cable
Overall distance 10km
Distance between
Refer to Section 3.2.2.
stations
Maximum number of
networks
Communication
Half duplex bit serial method
method
Transmission
Duplex loop
method
Modulation method
(Modulation method) CMI method
(Encoding method)
Transmission format HDLC standards (frame format)
Error control system CRC (X
• Loop-back function due to error detection or broken cable
RAS function
• Diagnostic function for checking local link lines
(Master station)
Number of occupied CPU integrated type: 0 point
I/O points Standalone:32 points per slot (I/O
assignment: special 32 points)
Specifications
MELSECNET (II) module
Optical loop
-
4096 points
First half: 1024 bytes
-
16 12 6
+X +X +1) and retry by a time over
: Compatible,
MELSECNET/H module
Optical loop
(QJ71LP21-25, QJ72LP25-25)
8192 points
16384 points
(Remote master station  remote I/O
station: 8192 points, remote I/O station 
remote master station: 8192 points)
16384 points
(Remote master station  remote I/O
station: 8192 points, remote I/O station 
remote master station: 8192 points)
Remote master station  remote I/O
station
{(LY + LB)  8 + (2 × LW)}
1600 bytes
Remote I/O station  remote master
station
{(LX + LB)  8 + (2 × LW)}
1600 bytes
4096 points
25Mbps/10Mbps
65 stations (Remote master station: 1,
remote I/O station: 64)
SI optical cable
H-PCF optical cable
Broad-band H-PCF optical cable
QSI optical cable
30km
Refer to Section 3.2.2.
239
Token ring method
(Encoding method) NRZI coding
(Master station)
32 points per slot (I/O assignment: intelli.
32 points)
: Partial change required, ×: Incompatible
Compat-
Precautions for replacement
ibility
Set the PLC to PLC network to
a separate network.
When using existing SI cables,
the distance between stations
may be shortened.
(Refer to Section 3.2.2.)
To ensure the same distance
as before replacement, either
change the optical cable, or
install a gateway station
midway along existing cables.
New MELSECNET/H
parameter (mandatory)
Nothing to be noted though the
communication method differs.
Nothing to be noted though the
modulation method differs.
When the master station is
replaced from a CPU
integrated type, one new slot
(32 points) is required.
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