Mitsubishi Electric Melsec A Series - Page 119

3 - 7
REPLACEMENT OF MELSECNET (II) AND /B (REMOTE I/O NETWORK)
3
: Compatible, : Partial change required, × : Incompatible
Item
Specifications
Compat-
ibility
Precautions for replacement
MELSECNET/B module MELSECNET/H module
Twisted pair
Optical loop
(QJ71LP21-25)
Coaxial bus
(QJ71BR11)
Communication
method
Half duplex bit serial method Token ring method
Nothing to be noted though the
communication method differs.
Transmission
method
Single bus
Duplex loop -
- Single bus
Modulation method
(Encoding method)
(Modulation method) NRZI method
(Encoding method)
NRZI coding
-
-
(Encoding method)
Manchester code
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 Diagnostic function for checking local link lines
Number of occupied
I/O points
(Master station)
Standalone: 32 points per slot (I/O
assignment: special 32 points)
(Master station)
32 points per slot (I/O assignment: intelli.
32 points)