Mitsubishi Electric Melsec A Series - Page 144

REPLACEMENT OF THE MELSECNET/10 (PLC TO PLC NETWORK)
4 - 3
4
(2) Performance comparison of AJ71QLP21S/A1SJ71QLP21S and QJ71LP21S-25
(MELSECNET/10 mode)
: Compatible, : Partial change required, ×: Incompatible
Item
Specifications
Compatibility Precautions for replacement
AJ71LP21/A1SJ71LP21
QJ71LP21-25
(MELSECNET/10 mode)
Maximum number
of link points per
network
X/Y 8192 points
B 8192 points
W 8192 points
Maximum number of link points
per station
{(Y + B)  8 + (2 × W)} 2000 bytes
Communication speed 10Mbps
Communication method Token ring method
Synchronous type Frame synchronization method
Encoding method NRZI coding (Non Return to Zero Inverted)
Transmission method Duplex loop
Transmission format HDLC standards (frame format)
Maximum number of networks
239 (Total number of PLC to PLC networks and remote I/O
networks)
Maximum number of groups 9
Number of stations connected in
one network
64 stations (Control station: 1, normal station: 63)
Applicable cable
SI optical cable, H-PCF optical cable, Broad-band H-PCF
optical cable, and QSI optical cable
Overall distance 30km
Distance between stations
SI optical cable: 500m, H-PCF optical cable: 1km, Broad-
band H-PCF optical cable: 1km, and QSI optical cable: 1km
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
• Prevention of system down by switching the control station
• Abnormal detection using link special relays and link
special registers
• Network monitoring and various diagnostic functions
Transient transmission
• N:N communication (e.g.
monitor, program up/
download)
• Dedicated link instruction
• N:N communication (e.g.
monitor, program up/
download)
• Dedicated link instruction
For comparison of dedicated
link instruction, refer to
Section 4.6.2.
External power
supply
Voltage 20.4VDC to 31.2VDC 20.4VDC to 31.2VDC
Current 0.2A 0.20A
Applicable
cable size
0.75 to 2mm
2
0.3 to 1.25mm
2
Cables of 1.25mm
2
or more
should be replaced with
cables of 0.3 to 1.25mm.
Number of occupied I/O points
AJ71QLP21S: 32 points per
slot (I/O assignment: special
32 points)
A1SJ71QLP21S: 48 points 2
slots (I/O assignment:
empty 16 points,
special 32
points)
48 points 2 slots
(I/O assignment:
empty 16 points,
intelli. 32
points)
When the AJ71QLP21S is
replaced, set the [Empty 16
points] of first half to the
[Empty 0 point] with I/O
assignment.
first half
second half
first half
second half