Mitsubishi Electric MELSEC-A Series Manual page 144

4
REPLACEMENT OF THE MELSECNET/10 (PLC TO PLC NETWORK)
(2) Performance comparison of AJ71QLP21S/A1SJ71QLP21S and QJ71LP21S-25
(MELSECNET/10 mode)
Item
X/Y
Maximum number
of link points per B
network
W
Maximum number of link points
per station
Communication speed
Communication method
Synchronous type
Encoding method
Transmission method
Transmission format
Maximum number of networks
Maximum number of groups
Number of stations connected in
one network
Applicable cable
Overall distance
Distance between stations
Error control system
RAS function
Transient transmission
Voltage
Current
External power
supply
Applicable
cable size
Number of occupied I/O points
4
- 3
Specifications
AJ71LP21/A1SJ71LP21
8192 points
8192 points
8192 points
{(Y + B)  8 + (2 × W)}
2000 bytes
10Mbps
Token ring method
Frame synchronization method
NRZI coding (Non Return to Zero Inverted)
Duplex loop
HDLC standards (frame format)
239 (Total number of PLC to PLC networks and remote I/O
networks)
9
64 stations (Control station: 1, normal station: 63)
SI optical cable, H-PCF optical cable, Broad-band H-PCF
optical cable, and QSI optical cable
30km
SI optical cable: 500m, H-PCF optical cable: 1km, Broad-
band H-PCF optical cable: 1km, and QSI optical cable: 1km
16 12 5
CRC(X + X + X + 1) and retry by a time over
• 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
• N:N communication (e.g. • N:N communication (e.g.
monitor, program up/
download)
• Dedicated link instruction • Dedicated link instruction
20.4VDC to 31.2VDC 20.4VDC to 31.2VDC
0.2A 0.20A
2
0.75 to 2mm 0.3 to 1.25mm
AJ71QLP21S: 32 points per
slot (I/O assignment: special
48 points 2 slots
32 points)
(I/O assignment:
A1SJ71QLP21S: 48 points 2
empty 16 points,
slots (I/O assignment:
empty 16 points,
first half
points)
special 32
second half
points)
: Compatible,
Compatibility
QJ71LP21-25
(MELSECNET/10 mode)
monitor, program up/
download)
2
first half
intelli. 32
second half
: Partial change required, ×: Incompatible
Precautions for replacement
For comparison of dedicated
link instruction, refer to
Section 4.6.2.
2
Cables of 1.25mm or more
should be replaced with
cables of 0.3 to 1.25mm.
When the AJ71QLP21S is
replaced, set the [Empty 16
points] of first half to the
[Empty 0 point] with I/O
assignment.