Cable Performance Comparisons - Mitsubishi Electric MELSEC-A Series Manual

2
REPLACEMENT OF MELSECNET (II) AND /B (PLC TO PLC NETWORK)
Item
Modulation
method (Encoding
method)
Transmission
format
Error control
system
RAS function
Occupied I/O
points

2.2.2 Cable performance comparisons

(1) Optical fiber cable
(a) Overall distance
The overall distance (30km) does not differ according to the optical fiber cable.
(b) Distance between stations
1) SI optical fiber cable
Type
SI optical fiber cable
(Type: A-2P-)
SI optical fiber cable
(Type: AN-2P-)
H-PCF optical fiber cable
Broad-band H-PCF optical fiber cable
QSI optical fiber cable
*1 When the distance between stations does not satisfy the MELSECNET/H specifications, either change the type of optical
fiber cable, or install a gateway station midway along existing cables.
*2 When the distance between stations does not satisfy the MELSECNET/H specifications, use at a communication speed of
10 Mbps, change the type of optical fiber cable, or install a gateway station midway along existing cables.
2) GI optical fiber cable
Type
GI optical fiber cable
2
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Specifications
MELSECNET/B module
Twisted pair
(Modulation method) NRZI method
HDLC standards (frame format)
16 12 5
CRC(X +X +X +1) and retry by a time over
Diagnostic function for checking local link lines
Standalone:32 points per slot (I/O
assignment: special 32 points)
MELSECNET ( II )
module
(optical loop)
L type 1km
H type 500m
1km
1km
-
-
MELSECNET ( II ) module
(optical loop)
2km
MELSECNET/H module
Optical loop Coaxial bus
(QJ71LP21-25) (QJ71BR11)
(Encoding method)
-
NRZI coding
(Encoding method)
-
Manchester code
32 points per slot (I/O assignment: intelli.
32 points)
: Compatible,
MELSECNET/H module
(optical loop)
10Mbps 25Mbps
500m 200m
300m 100m
500m 200m
1km 400m
1km 1km
1km 1km
: Compatible,
MELSECNET/H module Compat-
(optical loop)
2km
Compat- Precautions for
ibility replacement
Nothing to be noted though
the modulation method
differs.
: Partial change required, × : Incompatible
Compat- Precautions for
ibility replacement
*1
Refer to below.
*2
Refer to below.
: Partial change required, × : Incompatible
Precautions for replacement
ibility