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

2
REPLACEMENT OF MELSECNET (II) AND /B (PLC TO PLC NETWORK)

2.2 Performance Specifications Comparisons

2.2.1 Module performance comparisons

(1) Comparison between MELSECNET (II) module (optical loop) and MELSECNET/H module
(optical loop)
(a) SI optical fiber cable, H-PCF optical fiber cable
Item
Max. 2048 points and max. number of I/
X/Y O points of CPU module on master
station
Maximum • (MELSECNET mode) 1024 points
number of • (MELSECNET II mode),
B
link points
per network
• (MELSECNET mode) 1024 points
• (MELSECNET II mode),
W
• (MELSECNET mode) 1024 bytes
Maximum number • (MELSECNET II mode),
of link points per
station
Communication
speed
Number of stations
connected in one
local station + remote I/O station: 64)
network
Applicable cable
Overall distance
Distance between
stations
Maximum number
of networks
Communication
method
Transmission
method
Modulation method
(Encoding method)
Transmission
format
Error control
system
• Loop-back function due to error detection or broken cable
RAS function
• Diagnostic function for checking local link lines
CPU integrated type: 0 point,
Number of
standalone:32 points per slot (I/O
occupied I/O points
assignment: special 32 points)
2
- 3
Specifications
MELSECNET ( II ) module
Optical loop
(MELSECNET II composite mode)
4096 points
(MELSECNET II composite mode)
4096 points
(MELSECNET II composite mode)
First half: 1024 bytes
Second half: 1024 bytes
1.25Mbps
65 stations (master station: 1,
SI optical cable
H-PCF optical cable
10km
Refer to Section 2.2.2.
-
Half duplex bit serial method
Duplex loop
(Modulation method) CMI method
HDLC standards (frame format)
16 12 5
CRC(X +X +X +1) and retry by a time over
: Compatible,
MELSECNET/H module
Optical loop (QJ71LP21-25)
(MELSECNET/10 mode),
(MELSECNET/H mode),
(MELSECNET/H extended mode) 8192
points
• (MELSECNET/10 mode) 8192 points
• (MELSECNET/H mode),
(MELSECNET/H extended mode)
16384 points
• (MELSECNET/10 mode) 8192 points
• (MELSECNET/H mode),
(MELSECNET/H extended mode)
16384 points
• (MELSECNET/10 mode),
(MELSECNET/H mode)
{(LY+LB)  8+(2 × LW)}
2000 bytes
• (MELSECNET/H extended mode)
{(LY + LB)  8 + (2 × LW)}
35840
bytes
25Mbps/10Mbps
64 stations
(control station: 1 normal station: 63)
SI optical cable
H-PCF optical cable
Broad-band H-PCF optical cable
QSI optical cable
30km
Refer to Section 2.2.2.
239
Token ring method
(Encoding method) NRZI coding
32 points per slot
(I/O assignment: intelli. 32 points)
: Partial change required, × : Incompatible
Compat-
Precautions for replacement
ibility
When the number of bytes
exceeds 2000, mount two
modules having the same
network No., or set all modules
on the network in the
MELSECNET/H extended
mode.
• Set the remote I/O network
to a separate network.
• For the 65th station,
configure a separate
network.
When using existing SI cables,
the distance between stations
may be shortened. (Refer to
Section 2.2.2.)
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 replacing from a CPU
integrated type, an additional
slot (32 points) is required.