Mitsubishi Electric MELSEC-A User manual

PROGRAMMABLE CONTROLLER
hmlwc-A
User's Manual
Computer link/multidrop link module
type
AJ71 UC24
(Supplement)
CATALOG #JUM-454
$15.00
MlTSUBlSHl
ELECTRIC

REVISIONS
'The manual number is aiven onthe bottom left of the back cover.
Print Date *Manual Number Revision
IB
(NA) 66454-A First edition

INTRODUCTION
Thank you for choosing the Mitsubishi MELSEC-A Series of General Purpose Programmable Control-
lers. Please read this manual carefully so that the equipment is used to its optimum. A copy of this
manual should beforwarded to the end User.

CONTENTS
COMMON INFORMATION
. . 1 . GENERAL DESCRIPTION ............................................. 1 - 1 1 5
1 . 1
Contents of This Manual ................................................. 1 - 2
1.2
Features ............................................................... 1-3
1.2.1
Control operations usingthe multidrop link function .................... 1 - 4
2 .
SYSTEM CONFIGURATIONS .......................................... 2 - 1 . 2 . 7
2.1 Overall Configuration .................................................... 2 - 1
2.2
Applicable Systems ...................................................... 2 - 2
2.3
System Configurations and Available Functions (When Usingthe Computer Link
Function)
............................................................... 2-3
2.3.1 1
: 1 ratio of an external device (computer. etc.) to a PC CPU ........... 2 - 3
2.3.2 1
: n ratio of an external device (computer. etc.) to PC CPUs ............ 2 - 3
2.3.3 2
: 1 ratio of external devices (computer. etc.) to a PC CPU ............. 2 - 3
2.3.4 2
: n ratio of external devices (computer, etc.) to PC CPUs .............. 2 - 3
2.3.5
m : n ratio of external devices (computer. etc.) to PC CPUs ............. 2 - 3
2.4
When Selecting a Multidrop Link Function .................................. 2 - 4
2.4.1
When using an AJ71 UC24 as a master station ......................... 2 - 4
2.4.2
When using an AJ71UC24 as a local station ........................... 2 - 5
2.5
When Using a Multidrop Link Function and a Computer Link Function
Simultaneously
.......................................................... 2 - 6
(
2.6 Precautions Regarding System Configurations .............................. 2 - 7
COMPUTER LINK FUNCTION
. 3 . SPECIFICATIONS ................................................... 3 - 1 . 3 30
3.1 General Specifications ................................................... 3 - 1
3.2 Performance Specifications ............................................... 3 - 2
3.2.1
Transmission specifications ......................................... 3 - 2
3.2.2
RS-232C connector specifications ................................... 3 - 3
3.2.3 RS-4221485
interface specifications .................................. 3 - 3
3.2.4 RS-422
cable specifications ......................................... 3 - 3
3.3
Data Communications Functions .......................................... 3 - 4
........... 3.3.1 Functions available using dedicated protocols and commands
3 - 4
3.3.2
Functions available inthe no-protocol mode .......................... 3 - 11
3.3.3
Functions available inthe bidirectional mode ......................... 3 - 11
3.3.4
Transmission error data read function ............................... 3 - 11
3.4
Mode Switching Function During ComputerLink Operations .................. 3 - 11
3.4.1
Precautions when mode switching .................................. 3 - 12
3.4.2
Procedure for switching the mode from an external device ............. 3 - 18
3.4.3
Procedure for switching the mode from a PC CPU ..................... 3 - 21
3.5
Data Communications Transmission Control Function ....................... 3 - 24
(
3.6
110 Signals List for CPU ................................................. 3 - 24

.................................
3.7 Buffer Memory Applications and Allocation 3 - 27
...................
4 .
SETTINGS AND PROCEDURES BEFORE OPERATION
4 . 1 . 4 . 9
I
..................................
4.1 Settings and Procedures before Operation 4 - 1
...............................
4.2 Nomenclature and LED Signals and Dispalys 4 - 2
.....................................................
4.2.1 Nomenclature 4 - 2
4.2.2 LED signals and displays
........................................... 4 - 3
................................................................
4.3 Settings 4-5
4.3.1 Setting the dedicated protocol, no-protocol mode. or bidirectional mode
... 4 - 5
4.3.2 Setting of transmission specifications. main channels and terminal
resistance
........................................................ 4-5
.............................................
4.3.3 Station number setting 4 - 7
.....................................
4.3.4 Terminal resistance connections 4 - 7
..................................................
4.4 Loading and Installation 4 - 8
...............................................
4.4.1 Handling instructions 4 - 8
............................................
4.4.2 Installation environment 4 - 8
..
.........................................................
4.5 External Wmng 4 - 8
...........................................
4.5.1 Precautions during wiring 4 - 8
.................................
4.5.2 Connecting the RS-232C connectors 4 - 8
...............................
4.5.3 Connecting the RS-4221485connectors 4 - 9
4.5.4 Connecting a multidrop link and setting modes and terminal resistance
... 4 - 9
4.6 Self-IoopbackTest ....................................................... 4-9
4.7 LoopbackTest
.......................................................... 4- 9
..............................................
1
4.8 Maintenance and Inspection 4 - 9
5 .
HALF-DUPLEX COMMUNICATIONS USING THE RS-232C INTERFACE ........... 5 - I
6 .
DATA COMMUNICATIONS USING AN M:N MULTIDROP LINK ................... 6 - 1
7. INITIALSETTING OF TRANSMISSION CONTROL DATA TO BUFFER
MEMORY
........................................................... 7-1 -7-8
Setting RS-232C CD Terminal Check EnableIDisable
........................ 7 . 1
Setting the Transmission Method for RS-232C
.............................. 7 . 1
.......................................... Reading Transmission Error Data 7 . 1
Settings in the No-Protocol Mode
.......................................... 7 . 1
Settings in the Bidirectional Mode
......................................... 7 . 1
..................................................
Mode Switching Setting 7 . 2
7.6.1 Reading inthe mode setting state
.................................... 7 - 2
.........................................
7.6.2 Mode switching designation 7 - 2
Transmission Control Setting
............................................. 7 - 6
Reading RS-232C Signal Data
................... ; ........................ 7 - 6
Reading the Mode Setting Switch/Station Number Setting Switch Status
........ 7 - 7
7.10 Reading the Transmission Specification Setting Switch Statuses
............... 7 - 8
8 .
COMMUNICATIONS USING DEDICATED PROTOCOLS .................. 8 - I . 8 - 13
......................
D
8.1 Data Flow in Communications with Dedicated Protocols 8 - 1
...................................................... 8.2 Programming Hints 8-1

8.2.1 To write data to the special applications area inbuffer memory ..........8 - 1
8.2.2 PC CPU operation during data communications ........................8-1
8.2.3 Precautions during data communications
.............................. 8-1
8.3 Basics of Dedicated Protocol Control Procedures
............................ 8-1
8.4 Basic Formats of Dedicated Protocol
....................................... 8-1
8.4.1 Control format 1
................................................... 8-1
8.4.2 Control format 2
................................................... 8-1
8.4.3 Control format 3
................................................... 8-1
8.4.4 Control format
4 ................................................... 8-1
8.4.5 Setting protocol data ...............................................8-2
8.5 Transmission Sequence Timing Charts and CommunicationsTime .............8-3
8.6 Character Area DataTransmission
........................................ 8-4
8.7 Device Memory ReadIWrite
............................................... 8-5
8.7.1 Commands and device ranges .......................................8-5
8.7.2 Batch read in units of bits
........................................... 8-8
8.7.3 Batch read inunits of words
......................................... 8-8
8.7.4 Batchwrite in units of bits
.......................................... 8-8
8.7.5 Batchwrite in units of words
........................................ 8-8
8.7.6 Testing device memory inunits of bits (random write) .............
8.7.7 Testing device memory inunits of words (randomwrite) ..........
8.7.8 Monitoring device memory ....................................
8.8 Extension File Register Read and Write ..............................
8.8.1 ACPU common commands and addresses ......................
8.8.2 AnA dedicated commandsand device numbers ..................
8.8.3 Precautions during extension file register read/write .............
8.8.4 Batch read of the extension file register (ACPU commoncommand) ......
8.8.5 Batchwrite of the extension file register (ACPU commoncommand) 8-9
8.8.6 Direct readof the extension file register (AnACPU dedicated command) ..8
- 9
8.8.7 Direct write of the extension file register (AnACPU dedicated command) ..8
- 9
8.8.8 Testing (random write) the extension file register (ACPU common
command) ........................................................8-9
8.8.9 Monitoringthe extension file register
................................. 8-9
8.9 Buffer Memory Readand Write ............................................8-9
8.10 Special Function Module Buffer Memory Read and Write
..................... 8-9
8.11 Remote RunIStop of PC CPU and Reading PC CPU Model Name
.............. 8-9
8.11.1 Commands .......................................................8-9
8.11.2 Remote RUNISTOP
............................................... 8 -10
8.11.3 Reading PC CPU model name
...................................... 8 -10
8.11.4 Reading PC CPU model name and itscode
.......................... 8 -10
8.12 Program ReadlWrite
.................................................... 8 -11
8.12.1 Precautions during program readlwrite
............................... 8 -11
8.12.2 Program readlwrite control procedures ..............................8 -12
8.12.3 Parameter memory readlwrite
...................................... 8 -12
8.12.4 Sequence program readlwrite
...................................... 8 -12
8.12.5 Microcomputer program readlwrite
.................................. 8 -13
8.12.6 Comment memory readlwrite 8 -13
4
.......................................

..............................
8.12.7 Extension comment memory readlwrite 8 - 13
........................................................
8.13 Global Function 8-13
....................................................
8.14 On-demand Function 8 - 13
.........................................................
8.15 LoopbackTest 8-13
9 . COMMUNICATIONSWITH A COMPUTER INTHE NO-PROTOCOL MODE
......... 9 - 1
9.1 Basics of the No-ProtocolMode .....................................
9.2 Handshake IlOSignals .............................................
9.3 Programming Hints ................................................
9.3.1 To write data to the special applications area in buffer memory
....
9.3.2 Precautions during data communications ........................
9.4 Basic Programto ReadIWrite Buffer Memory ..........................
9.5 Receiving Data inthe No-Protocol Mode (External Device
+ AJ71UC24) .
9.6 Sending Data inthe No-ProtocolMode (AJ71UC24
+ External Device) . .
...........................
10. COMMUNICATIONS INTHE BIDIRECTIONAL MODE 10 - 1
...............................................
10.1 Bidirectional Mode Basics 10 - 1
....................................10.2 Handshake Signals and Buffer Memory 10 - 1
.....................................................
10.3 Programming Hints 10 - 1
10.3.1 System configuration and communications mode for bidirectional mode
. .
commun~cat~ons..................................................10-1
10.3.2 To write data to the special applications area in buffer memory
......... 10 - 1
10.3.3 Precautions during data communications
............................. 10 - 1
....................................
I
10.4 Bidirectional Control Procedure Basics 10 - 1
.....................................
10.5 Bidirectional Communications Basics 10 - 1
10.6 Processing an AJ71UC24 for Simultaneous Send in Full-Duplex Mode .........10
- 1
10.7 Basic Programto ReadIWrite Buffer Memory
............................... 10 - 1
10.8 Receiving Data inthe Bidirectional Mode (Computer
+ AJ71UC24) .......... 10 - 1
10.9 Transmitting Data inthe Bidirectional Mode (AJ71UC24
+ Computer) ......... 10 - 1
..............................................
11 . TROUBLESHOOTING 11 - 1 . 11 . 4
11 . 1 NAK Error Codes with Dedicated Protocols ................................11 - 1
....
...,
11.2 Bidirectional Mode Error Codes ....................
11.3 Troubleshooting ..................................
MULTIDROP LlNK FUNCTION
12
. SPECIFICATIONSFOR MULTIDROP LINK FUNCTION ...
12.1 Transmission Specifications .......................
12.2 RS-4221485Interface Specifications ................
12.3 RS-422 Cable Specifications .......................
13. SETTINGS AND PROCEDURES BEFORE OPERATION ...
13.1 Settings and Procedures before Operation ...........
........
D
13.2 Nomenclature and LED Signals and Displays
13.2.1 Nomenclature ..............................

13.2.2 LED signals and displays .............................. : ........... 13-3
13.3 Settings
............................................................... 13-4
13.3.1 Setting masterllocal station
........................................ 13 - 4
13.3.2 Settings of transmission specifications
............................... 13 - 4
13.3.3 Station number setting
............................................ 13 - 5
13.3.4 Connectionof terminal resistance
................................... 13 - 6
13.4 External Wiring
........................................................ 13 - 7
13.4.1 Multidrop link connection .......................................... 13 - 7
13.5 Self-loopback Test
...................................................... 13 - 8
13.5.1 Procedureto carry out self-loopbacktest
............................ 13 - 8
13.5.2 Self-loopbacktest operations
....................................... 13 - 9
. . 14 . AJ71UC24 MASTER STATION ...................................... 14 - 1 14 37
14.1 Functions ............................................................. 14 - 1
14.2 110 Signals List for PC CPU
.............................................. 14 - 2
14.3 Buffer Memory
......................................................... 14 - 3
14.3.1 Accessed slave station/transmissionpriority
.......................... 14 - 4
14.3.2 Number of communication data bits
................................. 14 - 5
14.3.3 Maximum number of transmissionpoints setting area
.................. 14 - 7
14.3.4 Off-communicationstation setting area
.............................. 14 - 7
14.3.5 Communicationdata area .......................................... 14 - 7
14.3.6 Faulty slave station indication
..................................... 14 - 10
14.3.7 Communicationtime
............................................ 14 - 10
14.3.8 Return request
................................................. 14 - 10
14.4 Data CommunicationsMethodswith Slave Stations with the Maximum
CommunicationsPoint Settingof 256 Points
............................. 14 - 12
14.4.1 Communicationwith AOJ2C25
.................................... 14 - 12
14.4.2 Communicationwith local station (AJ71UC24)
...................... 14 - 14
14.5 Data Communicationwith Slave Stationswhen the Maximum Number of
Transmission PointsisSet at 512
...................................... 14 - 16
14.5.1 Communicationwith AOJ2C25
.................................... 14 - 16
14.5.2 Communicationwith local station (AJ71UC24)
...................... 14 - 20
14.6 AJ71
UC24 Control .................................................... 14 - 22
14.7 Error Control
......................................................... 14 - 23
14.7.1 Pre-transmissionerror processing
................................ 14 - 23
14.7.2 Datatransmission error processing
............................... 14 - 24
.
14.8 Off-communicationControl ............................................ 14 26
. 14.9 Transmission Delay Time .............................................. 14 28
. 14.10 Transmission Stop DetectionTime ...................................... 14 28
14.11 Programming
........................................................ 14-29
14.11
. 1 Notes on programming .......................................... 14 - 29
14.11.2 Initial data write
................................................ 14-30
14.11.3 Start-up and error reset
.......................................... 14 - 31
14.11.4 Transmissiondata write
......................................... 14 - 32
14.11.5 Receiveddata read
............................................. 14 - 34
(
.
14.11.6 Off-communicationstation setlcancel program ...................... 14 - 37

.....................................
15 . MULTIDROP LOCALSTATION 15
- 1 . 15 . 10
.............................................................
15.1 Functions 15-1
............................................
15.2 Input Signals List for PC CPU 15 - 1
.........................................................
15.3 Buffer Memory 15 - 2
...................................................
15.3.1 Station number 15 - 3
15.3.2 Number of bits receivedltransmitted
................................. 15 - 3
15.3.3 Communication data
.............................................. 15 - 4
......................................................
15.4 AJ71UC24 Control 15 - 5
...........................................................
15.5 Error Control 15 - 6
15.5.1 Pre-transmission error processing
.................................. 15 - 6
15.5.2 Datatransmission error processing
................................. 15 - 6
15.6 Programming
.......................................................... 15-8
............................................ 15.6.1 Notes on programming 15 - 8
15.6.2 Transmission data write ........................................... 15 - 9
............................................. 15.6.3 Receiveddata read 15 - 10
16
.
TROUBLESHOOTING (MULTIDROP LINK FUNCTIONS) ................ 16 - 1 . 16 . 7
16.1 Error Codes (Master Station)
............................................. 16 - 1
16.2 Error Codes (Local Station)
.............................................. 16 - 2
16.3 Troubleshooting OFF
................................................... 16 - 3
16.3.1 Troubleshooting flow chart
......................................... 16 - 3
..............................................
16.3.2 RUN LEDturns OFF 16-4
.................................................
1 16.3.3 L2LEDturnsON 16-5
16.3.4 L3 LED turns ON
................................................. 16 - 7
APPENDICES ...................................................... APP . 1 . APP . 9
................................................ APPENDIX 1 EXTERNAL VIEW APP . 1
APPENDIX 2 PRECAUTIONS CONCERNING COMPATIBILITY AND THE USE OF
EXISTING PROGRAMS PREPARED FOR THE AJ71C24-S8 COMPUTER
LINK MODULE
.................................................. APP . 2
................................................ 2.1 Compatibility APP - 2
2.2 Precautions When Using Existing Programs
..................... APP - 2
2.3 Function Comparison
......................................... APP - 2
.............................................
APPENDIX 3 ASCII CODE TABLE APP . 3
APPENDIX 4 COMMUNICATIONS TIME BETWEEN A PC CPU AND AN AJ71UC24
.. APP . 3
APPENDIX 5 SPECIAL FUNCTION MODULE BUFFER MEMORY ADDRESSES
...... APP - 6
APPENDIX 6 PRECAUTIONS DURING COMMUNICATIONS WHEN USING RS-4221485
.................................................... .
INTERFACE APP 6
)
APPENDIX 7 SEQUENCE PROGRAM EXAMPLESSHOWING HOW TO OUTPUT WORD
DEVICE DATA TO THE PRINTER INTHE NO-PROTOCOL MODE
..... APP . 6

APPENDIX 8 EXAMPLE OFA SEQUENCE PROGRAM FOR DATA COMMUNICATIONS
IN THE BlDlRECRTlONAL MODE
.................................. APP . 6
. APPENDIX 9 AJ71UC24 SETTING RECORD FORM .............................. APP 7
. vii .

COMMON INFORMATION
r
This part describes the the system configuration, general specifications,
checks before test operation, and other information common to the opera-
tion of the
AJ71UC24 when it is used as a computer link module or mul-
tidrop link function module.

1. GENERAL'DESCRIPTION MELSEC-A
1. GENERAL DESCRIPTION
This User's Manual describes how to usethe AJ71UC24type computer
IinWmultidrop module (hereinaftercalledthe AJ71UC24).
This manualcovers the specifications and functionsthat cannot be found
inthe User's Manual for the AJ71C2468 computer link module (10-66360).
For specificationsand functions not contained herein, see the User's Man-
ualfor the AJ71C24-S8 priorto use of the AJ71UC24.
The AJ71UC24 isa modifiedversionof the conventionalAJ71C24-S8,
equippedwith an inexpensivemultidrop link function using an RS-4221485
interface.
The followingterminal resistances are packedwith the module:
330 a, 112 W (for RS-422communications)
110 a, 112 W (for RS-485communications)

1. GENERAL DESCRIPTION MELSEC-A
1.1 Contents of This Manual
This manual contains the information that is different from the contents of
the AJ71C2438 User's Manual.
Each section number in this manual correspondsto that inthe AJ71C24-
S8 User's Manual. Listed below are the section numbers with contents
different from those inthe AJ71C24-S8 User's Manual. When you reach
such section numbers in the AJ71C24-S8 User's Manual, replace them
with or refer to the contents of this manual.
(1) The terms which should be replaced in referring to the AJ71C2468
User's Manual
AJ71C24-S8 .. . . . AJ71UC24
RS-422.. ... . . ... RS-4221485
(2) Section numbers with different contents
System Configurations (When Selecting a Multidrop Link
Function)
When Using a Multidrop Link Function and a Computer Link
Function Simultaneously
RS-4221485 interface
Functions available using dedicated protocols and commands
Mode Switching Function While the Computer Link Module is
Operating
I10 Signals List for CPU
Buffer Memory Applications and Allocation
Nomenclature and LED Signals and Displays
Terminal resistance colmections
Remote RunIStop of PC CPU and Reading PC CPU Model
Name
NAK Error Codes with Dedicated Protocols
12to 16 MULTIDROP LINK FUNCTION
The section numbers in Chapter 1 and Appendix do not match those in the AJ71C24-S8 User's
Manual.

1. GENERAL DESCRIPTION MELSEC-A
1.2 Features
(1) Storing switch settings inbuffer memory
The settingsof the switches (mode setting, station number setting
and transmissionspecificationsetting) on the face of the AJ71UC24
and the RS-232Csignal data can be read out of the buffer memory to
check.
(2) Multidroplinkfunction added
For the multidrop link function, a flexible, inexpensiveinput/output sig.
nalcommunicationssystem usingan RS-4221485 interfacs canbe set
UP.
This function permitsinpuWoutput signal communications betweena
master station and local or remote stations. Up to eight localor re-
motestations are connectableto a master station.
Master station
Localstation
No.1 Remotestation No.2 Localstation No.3 Local station No.8
mi rm m[Tl
P :, ~0~2~25' p $ rn p $
LJ i-
" ::; ,, ii
The AOJ2C25 isavailablewith a stationnumber from 1 to 4.
[ : A171UC24
(a) When using the AJ71UC24 as a master station
1) A total of eight slave stations (local station: AJ71UC24,
AlSJ71C24-R4, AOJ2-C214 (SI), remotestation: AOJ2C25)
can be connectedto a master station.
2) Uptoeight AJ71UC24s can be set as master stations with a
PC CPU.
3) The transmission speed in the link, the total extensiondis-
tance, and the maximum numberof link points are 38400 BPS,
500 m, and 512 points (maximum 128 input points and 128out-
put points per slave station) respectively.
4) If a linkingslave station is down, it can bedisconnectedfrom
the link system to continuenormaldata link operations or dis-
continue data transmission to the entire link system.
5) A designatedslave station can be isolated (which meansthe
data to betransferredto and from the station will be all OFF)
(b) When using the AJ71UC24 as a local station
I)The AJ71C22 (Sl), AJ71UC24, AlSJ71C24-R4 or AOJ2-C214
(SI) can be used as the master station.
2) A total of eight AJ71UC24s are connectable as local stations to
a master station.
3) The maximumtransmission speed inthe link is38400 BPS,
however, the maximum numberof link points depends on the
allocationinthe master station.
1-3

1. GENERAL DESCRIPTION MELSEC-A
1.2.1 Controloperations using the multidroplinkfunction
The multidrop link function controls the following operations:
(1) When an AJ71UC24 is used as a master station
(a) Writing the bit device status in the PC CPU (master station) to the
buffer using a TO instruction.
(b) Writing data via the RS-422 cable to the buffer in a local station.
(c) Reading receive data (in the buffer) in the PC CPU using a FROM
instruction.
(d) Writing the bit device status in the PC CPU (local station) to the
buffer using a TO instruction.
(e) Writing data (inthe local or remote station) via the RS-422 cable to
the buffer ina master station.
(f) Reading receive data (in the buffer) inthe PC CPU using a FROM
instruction.
(g) Outputting send data in the buffer (in a master station) to the buffer
in a remote station.
(h) Writing data (input from an external device) as the receiveddata to
the buffer in a master station.
PCCPU Al71UC24
I I Rate rtatlon
PCCPU AJ71UC24 kUZC2S

1. GENERAL DESCRIPTION MELSEC-A
(2) When an AJ71 UC24 is used as a local station
(a) Writing the bit device status in the PC CPU (local station) to the
buffer usinga TO instruction.
(b) Writing data via the RS-422cableto the buffer ina master station.
(c) Reading receive data (in the buffer) in the PC CPU using a FROM
instruction.
(d) Writing the bit device status inthe PC CPU (master station) to the
buffer using a TO instruction.
(e) Writing data via the RS-422cable tothe bufferin a local station.
(f) Reading receive data (in the buffer) in the PC CPU using a FROM
instruction.
Ld station
PCCPU AJ71UC24

2. SYSTEM CONFIGURATIONS MELSEC-A
2. SYSTEM CONFIGURATIONS
This chapter describes system configurations compatible with the
AJ71 UC24.
2.1 Overall Configuration
Fig. 2.1 shows the overall configuration of a system which is loaded with
the AJ71 UC24.
-
- : RS422cable
- : RS-232Cor RS-422 caMe
I Exterm1device
I
I
I
Computer link:
I Multidroplink:
L----------------~ Masterstation
Multidroplink
-
-
T
BuildingMock type CPU
I--+
Buildingblock type CPU
ri
Mainbaseunit (A3[]B)
itensioncaMe (AC[ I[]B)
Station 1 AJ71UC24 Mainbaseunit (A3[]B)
AOJ2C25 remote
110 module
Station2 Station 1 PJ71UC24
I
3tensioncable (AC[I[]E
multidroplink
module
Station3
computer link
module
Extensionbase units Station2
1
Extensionbaseunits
\5[10) ... Wnh na buin-in power supdy
<6[10) ... Wdh bib-in pow ruwly
I
Station31
L ---- ----
station 8
-----------------
Fig. 2.1 Overall Configuration
2-1

2. SYSTEM CONFIGURATIONS MELSEC-A
2.2 ApplicableSystems
The AJ71UC24can be usedwith the systems described below.
I
(1) Applicable PC CPU modules and the number of AJ71UC24 modules to
beconnected
(a) The table below shows the applicable PC CPU modulesfor which
the AJ71UC24 will be used as the computer link, andthe number
of AJ71UC24 modules to beconnected to the modules.
Each applicable PC CPU module includes a module equipped with
an MELSECNET link function.
e.g. The A2ACPU includes an A2ACPUP21 and an A2ACPUR21
[ to both of which an AJ71UC24 can be connected.
I
Applicable Number of
PC CPU ( Connectable
Modules
AJ71 UC24s
I
'he AJ71UC24 is unapplicable I
Remarks
Iteach of the following modules isused with the
AJ71UC24, the maximum number of connectable
AJ71UC24 modules to itmust not exceed 2 or 6.
ADsl(S3) Intelligent Communication Module
AD51H(S3) Intelligent Communication Module
AD51FD External Failure Diagnosis Module
AD57G Graphic Controller Module
. AJ71C21(Sl) Terminal Interface Module (only in
BASIC Program Mode)
. AJ71C22(S1) Multidrop Link System Module
. AJ71C23 Hioher Controller Hiah SDmd Link Module
. ~~71~24(-~:3/S6/~8)Cornput& ink Module
A.171P41 SUMINET Interface Module
.. - . . . .. .. .. .. .. - . ... . . .. -. . . .. .. - -
AJ71E71 Ethernet Interface Module
AJ71UC24 Computer LinWMuitidrop Link Module
he AOJ2CPU and the A2CCPU.)
(2) Applicable base unit
The AJ71UC24 can be inserted into any slot of a main base unit or
extension base unit, except for the following two cases:
(a) The power supply capacity of the extension base unit (A55B or
A58B) with no built-in power supply may be insufficient to loadthe
AJ71UC24 into it. Wherever possible, avoid loading an
AJ71UC24 module into this type of extension base unit.
If such an extension base unit requires an AJ71UC24 module, se-
lect a power supply unit and extension cables after due considera-
tion for both the capacity of the power supply unit andthe voltage
drop inthe extension cables.
(For details, see the User's Manual for each applicable PC CPU
module (see (1) above).)
(b) The AJ71UC24 should not be loaded intothe last slot of the
A3CPU extension level 7.
POINTS
One AJ71UC24 can be loaded into the A81CPU base unit (A78B) also.
For available commands, see the A81CPU User's Manual.
r
The AJ71UC24cannot be used in a remote I10 station.