Mitsubishi Electric MELSEC-A User Manual page 16

1. GENERAL DESCRIPTION
MELSEC-A
1.2
Features
(1) Storing switch settings in buffer memory
The settings of the switches (mode setting, station number setting
and transmission specification setting) on the face of the AJ71 UC24
and the RS-232C signal data can be read out of the buffer memory to
check.
(2) Multidrop link function added
For the multidrop link function, a flexible, inexpensive input/output sig.
nal communications system using an RS-4221485 interfacs can be set
UP.
This function permits inpuWoutput signal communications between a
master station and local or remote stations. Up to eight local or re-
mote stations are connectable to a master station.
Master station
Local station No.1 Remote station
No.2
Local station No.3 Local station No.8
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The AOJ2C25 is available with a station number from 1 to
4.
[
: A171UC24
(a) When using the AJ71 UC24 as a master station
1) A total of eight slave stations (local station: AJ71 UC24,
AlSJ71C24-R4, AOJ2-C214 (SI), remote station: AOJ2C25)
can be connected to a master station.
2) Up to eight AJ71UC24s can be set as master stations with a
PC CPU.
3) The transmission speed in the link, the total extension dis-
tance, and the maximum number of link points are 38400 BPS,
500 m, and 512 points (maximum 128 input points and 128 out-
put points per slave station) respectively.
4) If a linking slave station is down, it can be disconnected from
the link system to continue normal data link operations or dis-
continue data transmission to the entire link system.
5) A designated slave station can be isolated (which means the
data to be transferred to and from the station will be all OFF)
(b) When using the AJ71 UC24 as a local station
I ) The AJ71C22 (Sl), AJ71 UC24, AlSJ71C24-R4 or AOJ2-C214
(SI) can be used as the master station.
2) A total of eight AJ71 UC24s are connectable as local stations to
a master station.
3) The maximum transmission speed in the link is 38400 BPS,
however, the maximum number of link points depends on the
allocation in the master station.
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