IDEC FC4A Series Instruction Manual

MICROSMART COMMUNICATION PROTOCOL

This document describes communication commands for the MicroSmart micro programmable controller.

Table of Contents
Communication Command List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 1
Communication Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 2
Message Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	2
Request Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	3
Receive Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	4
Reply Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
Write User Program in ASCII Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	7
Write User Program in Binary Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	9
Read User Program in ASCII Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	11
Read User Program in Binary Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	13
Write N Bytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15
Read N Bytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	18
Write 1 Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	21
Read 1 Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	23
Read Error Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	25
Clear Operand Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	29
Enable/Disable User Program Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	31
Read PLC Operating Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	33
Read Scan Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	34
Read PLC System Program Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	35
Read Timer Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	36
Read Counter Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	38
Read Timer Preset Value Change Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	40
Read Counter Preset Value Change Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	42
Read Timeout Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	44
Read Countout Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	45
Confirm Changed Timer/Counter Preset Values . . . . . . . . . . . . . . . . . . . . . . . . . . .	46
NG Code and Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	47
Operand Allocation Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	48
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	49

www.idec.com

MICROSMART COMMUNICATION PROTOCOL

Communication Command List

All communication commands available for the MicroSmart, OpenNet Controller (ONC), MICRO3, and MICRO3C are summarized in the table below. Some of the commands are the same as for different PLCs, with increased operands and operand number ranges.

Command Name	MicroSmart	ONC	MICRO3C	MICRO3
Write User Program in ASCII Format	X	X	X	X
Write User Program in Binary Format	X	X	X	X
Read User Program in ASCII Format	X	X	X	X
Read User Program in Binary Format	X	X	X	X
Write N Bytes	X	X	X	X
Read N Bytes (Note)	X	X	X	X
Write 1 Bit	X	X	X	X
Read 1 Bit	X	X	X	X
Read High-speed Counter Preset and Current Values		X	X	X
Read Error Code	X	X	X	X
Clear Operand Data	X	X	X	X
Enable/Disable User Program Protection	X	X	X	X
Read PLC Operating Status	X	X	X	X
Read Scan Time	X	X	X	X
Read PLC System Program Version	X	X	X	X
Read User Communication Transmit/Receive Buffer		X	X
Clear and Start User Communication Data Monitor			X
Read User Communication Status		X	X
Read Communication Mode		X
Select Word Operands for Monitor		X
Monitor Selected Word Operands		X
Read Timer Information	X	X
Read Counter Information	X	X
Read Timer Preset Value Change Status	X	X
Read Counter Preset Value Change Status	X	X
Read FUN Area Settings		X
Read Random Words		X
Read Timeout Status	X
Read Countout Status	X
Confirm Changed Timer/Counter Preset Values	X

Note: When timer/counter preset or current values are read out from the MicroSmart using the read N bytes command, the result is different from that read from the MICRO3 because the MicroSmart has different timer and counter internal codes to enable 16-bit timers and counters. The MicroSmart has new commands for timers and counters; Read Timeout Status and Read Countout Status.

MICROSMART

1

MICROSMART COMMUNICATION PROTOCOL

Communication Procedure

The computer and the MicroSmart CPU module communicate data by sending and receiving communication messages, which consist of request messages and reply messages. The request message is sent from the computer to write data to, read or clear data from the MicroSmart. The reply message is sent from the MicroSmart in response to the request message from the computer.

Communication is always initiated by the computer by sending a request message to the MicroSmart, which then returns a reply message to the computer. The MicroSmart cannot initiate communication in the computer link system. The MicroSmart can initiate communication using the user communication function.

		Request Message
	Computer	MicroSmart
		CPU Module
		Reply Message

Message Format

Communi-

BCC (Block Check Character) Calculation Range

cation

Message

(1)

(2)

(3)

(4)

(5)

Communication

ENQ (05h)

Enquiry

Request message

(1)

control

Message start

ACK (06h)

Acknowledge

character

character

Reply message

NAK (15h)

Negative acknowledge

(1 byte)

00 (0)

Designates a PLC device number to which the com-

Device number to

through

puter sends a request message in the 1:N communi-

1F (31)

cation computer link system.

Communication

send request to

(2)

FF (255)

Used in the 1:1 communication computer link system.

device number

PLC of any device number receives request message.

(2 bytes)

Device number to

00 (0)

Indicates the device number of the PLC which returns

through

send reply from

the reply message.

1F (31)

(3)

Data

Communication

Depends on each command.

command,

See “Request Messages” on page 3.

(variable length)

data type, etc.

See “Reply Messages” on page 5.

(4)

BCC

Block check

Exclusive OR (XOR) of the BCC calculation range.

(2 bytes)

character

(5)

Terminator

Message

CR (0Dh)

Default

(1 byte)

end code

MICROSMART

2

MICROSMART COMMUNICATION PROTOCOL

Request Messages

Like the ONC or MICRO3, request messages are available in request message 1 and request message 2 with different data structures.

Request Message 1

Request message 1 is a command message to be sent from the computer to the PLC, containing a command. The data type code included in the request message determines the function. The data structure of request message 1 is shown below.

Request

ENQ

05h

Device

(1)

(2)

(3)

(4)

BCC

Termi-

Message 1

nator

(1)

Continuation

0 (30h)

Discontinued (no message follows)

(1 byte)

1 (31h)

Continued (another message follows)

Command

W (57h)

Write data to PLC

(2)

R (52h)

Read data from PLC

(1 byte)

C (43h)

Clear data from PLC

X (58h)

Input

t (74h)

Timer

(current value)

Y (59h)

Output

N-byte

Counter

c (63h)

designation

M (4Dh)

Internal relay

(current value)

N-byte

R (52h)

Shift register

D (44h)

Data register

designation

T (54h)

Timer

x (78h)

Input

(preset value)

y (79h)

Output

1-bit

C (43h)

Counter

m (6Dh)

Internal relay

designation

(preset value)

r (72h)

Shift register

E (45h)

Error code (read/clear)

I (49h)

Link formatting sequence (clear)

K (4Bh)

Scan time (read)

(3)

Data type

N (4Eh)

PLC system program version (read)

(1 byte)

P (50h)

User program in ASCII format (read/write)

Q (51h)

Changed timer/counter preset values (write)

S (53h)

PLC operating status (read)

V (56h)

User program protection

W (57h)

Calendar/clock (read/write)

Z (5Ah)

System reset (clear)

_ (5Fh)

Timer information (read)

` (60h)

Counter information (read)

a (61h)

Timer preset value change status (read)

b (62h)

Counter preset value change status (read)

d (64h)

Timer timeout status (read)

e (65h)

Counter countout status (read)

p (70h)

User program in binary format (read/write)

(4)

Data

Data (depends on command and data type)

(variable length)

(1)“Continued” is used in request message 1 for writing the user program to inform the PLC that another request message will be sent successively. In all other request messages, “discontinued” is used. When “continued” is specified, the computer sends a request message, receives a reply message, and sends another request message.

(2)The command code is available in three types; write data, read data, and clear data.

(3)The data type code selects an operand or function. Upperand lower-case characters have different functions.

(4)The data specifies the operand number, the quantity of bytes of the data for reading or writing, etc. depending on the command and data type.

MICROSMART

3

MICROSMART COMMUNICATION PROTOCOL

Request Message 2

Request message 2 is a command message used for writing and reading user programs. The data structure of request message 2 is shown below:

Request

ENQ

05h

Device

(1)

(2)

BCC

Termi-

Message 2

nator

(1)

Continuation

0 (30h)

Discontinued (no message follows)

(1 byte)

Data

User program (write user program)

(variable length)

(2)

Data

R (52h) Read user program

(1 byte)

(1)“Discontinued” is used for both writing and reading user programs to inform the PLC that no request message will be sent successively.

(2)The data length is variable for writing user programs and is 1-byte long (“R”) for reading user programs.

Receive Timeout

When a request message contains an interval of 500 msec or more between onebyte character data and the next one-byte character data, the PLC understands that the communication is canceled and does not return a reply message.

When the interval is 500 msec or more, extend the receive timeout value using WindLDR. The receive timeout can be selected between 10 and 2540 msec in 10msec increments. To enable the optional communication mode, turn on the mode selection input designated on the Communication Parameters page in WindLDR.

	Data		Data

≤ 500 msec

To access the Communication Parameters page from the WindLDR menu bar, select Configure > Function Area Settings. In the Function Area Setting dialog box, click the Communication tab, and select Maintenance Protocol in the Port 1 or 2 pull-down list.

Click the Configure button. The Communication Parameters dialog box appears. Change settings, if required.

Baud Rate (bps)	1200, 2400, 4800, 9600, 19200
Data Bits	7 or 8
Parity	None, Odd, Even
Stop Bits	1 or 2
	10 to 2540 (10-msec increments)
Receive Timeout (ms)	(Receive timeout is disabled when 2550
	is selected.)
Device Number	0 to 31
Mode Selection Input	Any input number

Note: Only when the mode selection input is turned on, the selected communication parameters are enabled. Otherwise, default communication parameters take effect; 9600 bps, 7 data bits, even parity, 1 stop bit, receive timeout 500 msec.

For details, see the MicroSmart User’s Manual EM342, page 25-2.

MICROSMART

4

MICROSMART COMMUNICATION PROTOCOL

Reply Messages

Reply messages are available in ACK reply message and NAK reply message with different data structures.

ACK Reply Message

The ACK reply message is a reply or response to the request message and is sent from the PLC to the computer when communication is completed normally.

ACK

ACK

Reply

06h

Device

(1)

(2)

BCC

Termi-

Message

nator

0 (30h)

OK: Discontinued

All communication is completed normally (end of processing).

1 (31h)

OK: Continued

Communication in reply to request is completed normally and

another reply message follows when reading a user program.

Command

(1)

Communication device number, command, data type, data, or con-

(1 byte)

tinuation code is not within the range supported by the PLC or

2 (32h)

NG: Error

does not match its status. When this error occurs, communication

is halted without regard to the continuation code.

OK

When request command is W or C

No data exists. (0 byte)

The data length depends on the request

reply

When request command is R

command (variable length).

NG code (2 bytes)

NG

Error

Cause

Code

01

Program size error

Improper write/read program size

02

Protect error

Protected against write/read in the PLC

0 (30h)

03

RUN error

Writing user program is attempted while the PLC

is running

to

04

CRC error

User program CRC code does not match

9 (39h)

05

Data

Protect code error

Protect code in the request message does not

(2)

(variable

or

match that set in the PLC. Attempt was made to

length)

A (41h)

NG

enable protection on a protected user program.

reply

06

Data range error

Invalid data range designated

to

07

Timer/counter preset

Preset value change is attempted to timer or

F (46h)

value change error

counter with preset value designated by data reg-

ister

08

Calendar/clock data error

Invalid value written to calendar/clock

09

Data clear error

Designated data cannot be cleared

10

Data error

Invalid data other than 0 (30h) - 9 (39h) or

A (41h) - F (46h)

11

Setting error

Incorrect setting for user communication

12

CPU module type code

CPU module type code in the request message

error

does not match the connected PLC.

(1)The command code indicates whether the request command is completed normally or not and also whether another reply message will be sent successively.

When reading a user program from the PLC, reply message 1 is returned in response to request message 1 and reply message 2 is returned in response to request message 2. Reply message 1 contains command 1 (OK: continued) to inform the computer that another reply message follows. All other reply messages contain command 0 (OK: discontinued) to indicate that no reply message follows when communication is completed normally.

(2)When an OK reply is returned in response to request command R (read data), the read data is included in this place. When an NG reply is returned, the cause of error exists in the PLC. See page 47.

MICROSMART

5

MICROSMART COMMUNICATION PROTOCOL

NAK Reply Message

When an error is found during communication, a NAK reply message is sent from the PLC to the computer.

NAK

NAK

Reply

15h

Device

(1)

(2)

BCC

Termi-

Message

nator

(1)

Command

0 (no meaning): dummy data for consistent communication format

Depending on the communication error, an error code is set in this place.

Error

Error Type

Error Contents

Code

00

BCC error

Appended BCC code does not match BCC calculated

Communication

value of received data.

01

Frame error

Quantity of received bits differs from the preset

(2)

error code

(2 bytes)

value (stop bit is 0 for example).

02

Data send/receive error

Parity error or overrun error occurred.

03

Command error

Unsupported request message is received.

04

Procedure/data quantity error

Received request message does not match the

expected data (including quantity of data).

(1)The command code in the NAK reply message is always 0.

(2)The next two bytes indicate the communication error code.

MICROSMART

6

MICROSMART COMMUNICATION PROTOCOL

Write User Program in ASCII Format

The user program can be written from a computer to the PLC. When transferring a user program through modem, this command is recommended to transfer the user program in ASCII format because modems understand ASCII codes.

When writing a user program from a computer, two request messages must be sent to the PLC.

Send request message 1 first. After confirming that the returned reply message is an OK reply, send request message 2.

Request Messages (Write User Program in ASCII Format)

Request Message 1

05h

**

**

31h

57h

50h

3*h

**

**

**

**

**

**

**

**

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(1)

Communication control character

1 byte

ENQ (05h)

Enquiry

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

FF

Device number 255 (all devices)

(3)

Continuation

1 byte

1 (31h)

Continued

(4)

Command

1 byte

W (57h)

Write data

(5)

Data type

1 byte

P (50h)

User program in ASCII format

0 (30h)

10-I/O

1 (31h)

16-I/O

(6)

CPU module type code

1 byte

2 (32h)

20-I/O transistor output

3 (33h)

24-I/O

4 (34h)

40-I/O

6 (36h)

20-I/O relay output

0000 0000

User program includes data of rung

(7)

comments and tag comments plus

Program capacity

8 bytes

:

function area settings. The function

FFFF FFFF

area occupies 94 bytes.

(8)

BCC

2 bytes

00 - 7F

Block check character

(9)

Terminator

1 byte

CR (0Dh)

Message end code

Request Message 2

05h

**

**

30h

**

**

**

**

**

**

**

**

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(1)

Communication control character

1 byte

ENQ (05h)

Enquiry

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

FF

Device number 255 (all devices)

(3)

Continuation

1 byte

0 (30h)

Discontinued

(4)

User program

Variable length

0 (30h) - 9 (39h)

User program (ASCII code file)

64,336 bytes max.

A (41h) - F (46h)

(5)

BCC

2 bytes

00 - 7F

Block check character

(6)

Terminator

1 byte

CR (0Dh)

Message end code

Note: The user program must be stored in a file of the ASCII code format. Ladder program files (.LDR) cannot be sent to the PLC using this request message.

MICROSMART

7

MICROSMART COMMUNICATION PROTOCOL

Reply Messages (Write User Program in ASCII Format)

OK Reply (Reply to Request Messages 1 and 2)

06h

**

**

30h

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(1)

Communication control character

1 byte

ACK (06h)

Acknowledge

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

(3)

Command

1 byte

0 (30h)

OK: Discontinued

(4)

BCC

2 bytes

00 - 7F

Block check character

(5)

Terminator

1 byte

CR (0Dh)

Message end code

NG Reply (Reply to Request Message 1)

06h

**

**

32h

30h

3*h

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(1)

Communication control character

1 byte

ACK (06h)

Acknowledge

(2)

Communication device number

2 bytes

00

- 1F

Device number 0 through 31

(3)

Command

1 byte

2 (32h)

NG

01

(30h 31h)

Program capacity error

(4)

02

(30h 32h)

Protect error

NG code

2 bytes

03

(30h 33h)

RUN error

04

(30h 34h)

CRC error

12

(31h 32h)

CPU module type code error

(5)

BCC

2 bytes

00

- 7F

Block check character

(6)

Terminator

1 byte

CR (0Dh)

Message end code

Note: NG reply never occurs in response to reply message 2.

MICROSMART

8

MICROSMART COMMUNICATION PROTOCOL

Write User Program in Binary Format

The user program can be written from a computer to the PLC. This command can send a user program faster than the Write User Program in ASCII format command.

When writing a user program from a computer, two request messages must be sent to the PLC.

Send request message 1 first. After confirming that the returned reply message is an OK reply, send request message 2.

Request Messages (Write User Program in Binary Format)

Request Message 1

05h

**

**

31h

57h

70h

3*h

**

**

**

**

**

**

**

**

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(1)

Communication control character

1 byte

ENQ (05h)

Enquiry

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

FF

Device number 255 (all devices)

(3)

Continuation

1 byte

1 (31h)

Continued

(4)

Command

1 byte

W (57h)

Write data

(5)

Data type

1 byte

p (70h)

User program in binary format

0 (30h)

10-I/O

1 (31h)

16-I/O

(6)

CPU module type code

1 byte

2 (32h)

20-I/O transistor output

3 (33h)

24-I/O

4 (34h)

40-I/O

6 (36h)

20-I/O relay output

0000 0000

User program includes data of rung

(7)

comments and tag comments plus

Program capacity

8 bytes

:

function area settings. The function

FFFF FFFF

area occupies 94 bytes.

(8)

BCC

2 bytes

00 - 7F

Block check character

(9)

Terminator

1 byte

CR (0Dh)

Message end code

Request Message 2

05h

**

**

30h

**

**

**

**

**

**

**

**

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(1)

Communication control character

1 byte

ENQ (05h)

Enquiry

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

FF

Device number 255 (all devices)

(3)

Continuation

1 byte

0 (30h)

Discontinued

(4)

User program

Variable length

(00h) - (FFh)

User program (binary code file)

32,168 bytes max.

(5)

BCC

2 bytes

00 - FF

Block check character

(6)

Terminator

1 byte

CR (0Dh)

Message end code

Note: The user program must be stored in a file of the binary code format. Ladder program files (.LDR) cannot be sent to the PLC using this request message.

MICROSMART

9

MICROSMART COMMUNICATION PROTOCOL

Reply Messages (Write User Program in Binary Format)

OK Reply (Reply to Request Messages 1 and 2)

06h

**

**

30h

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(1)

Communication control character

1 byte

ACK (06h)

Acknowledge

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

(3)

Command

1 byte

0 (30h)

OK: Discontinued

(4)

BCC

2 bytes

00 - 7F

Block check character

(5)

Terminator

1 byte

CR (0Dh)

Message end code

NG Reply (Reply to Request Message 1)

06h

**

**

32h

30h

3*h

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(1)

Communication control character

1 byte

ACK (06h)

Acknowledge

(2)

Communication device number

2 bytes

00

- 1F

Device number 0 through 31

(3)

Command

1 byte

2 (32h)

NG

01

(30h 31h)

Program capacity error

(4)

02

(30h 32h)

Protect error

NG code

2 bytes

03

(30h 33h)

RUN error

04

(30h 34h)

CRC error

12

(31h 32h)

CPU module type code error

(5)

BCC

2 bytes

00

- 7F

Block check character

(6)

Terminator

1 byte

CR (0Dh)

Message end code

Note: NG reply never occurs in response to reply message 2.

MICROSMART

10

MICROSMART COMMUNICATION PROTOCOL

Read User Program in ASCII Format

The user program can be read from the PLC to a computer.

When reading a user program to a computer, two request messages must be sent from the computer to the PLC.

Send request message 1 first. After confirming that the returned reply message is an OK reply, send request message 2.

Specify a value larger than the user program capacity selected in the PLC in place of the program capacity in request message 1. Reserve a buffer in the computer to store the data of the specified program capacity temporarily.

Request Messages (Read User Program in ASCII Format)

Request Message 1

05h

**

**

31h

52h

50h

3*h

**

**

**

**

**

**

**

**

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(1)

Communication control character

1 byte

ENQ (05h)

Enquiry

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

FF

Device number 255 (all devices)

(3)

Continuation

1 byte

1 (31h)

Continued

(4)

Command

1 byte

R (52h)

Read data

(5)

Data type

1 byte

P (50h)

User program in ASCII format

0 (30h)

10-I/O

1 (31h)

16-I/O

(6)

CPU module type code

1 byte

2 (32h)

20-I/O transistor output

3 (33h)

24-I/O

4 (34h)

40-I/O

6 (36h)

20-I/O relay output

0000 0000

User program includes data of rung

(7)

comments and tag comments plus

Program capacity

8 bytes

:

function area settings. The function

FFFF FFFF

area occupies 94 bytes.

(8)

BCC

2 bytes

00 - 7F

Block check character

(9)

Terminator

1 byte

CR (0Dh)

Message end code

Request Message 2

05h

**

**

30h

52h

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(1)

Communication control character

1 byte

ENQ (05h)

Enquiry

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

FF

Device number 255 (all devices)

(3)

Continuation

1 byte

0 (30h)

Discontinued

(4)

Command

1 byte

R (52h)

Read data

(5)

BCC

2 bytes

00 - 7F

Block check character

(6)

Terminator

1 byte

CR (0Dh)

Message end code

MICROSMART

11

MICROSMART COMMUNICATION PROTOCOL

Reply Messages (Read User Program in ASCII Format)

OK Reply

• Reply Message 1

06h

**

**

31h

3*h

**

**

**

**

**

**

**

**

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(1)

Communication control character

1 byte

ACK (06h)

Acknowledge

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

(3)

Command

1 byte

1 (31h)

OK: Continued

0 (30h)

10-I/O

1 (31h)

16-I/O

(4)

CPU module type code

1 byte

2 (32h)

20-I/O transistor output

3 (33h)

24-I/O

4 (34h)

40-I/O

6 (36h)

20-I/O relay output

0000 0000

User program includes data of rung

(5)

comments and tag comments plus

Program capacity

8 bytes

:

function area settings. The function

FFFF FFFF

area occupies 94 bytes.

(6)

BCC

2 bytes

00 - 7F

Block check character

(7)

Terminator

1 byte

CR (0Dh)

Message end code

• Reply Message 2

06h

**

**

30h

**

**

**

**

**

**

**

**

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(1)

Communication control character

1 byte

ACK (06h)

Acknowledge

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

(3)

Command

1 byte

0 (30h)

OK: Discontinued

(4)

User program

Variable length

0 (30h) - 9 (39h)

User program (ASCII code file)

64,336 bytes max.

A (41h) - F (46h)

(5)

BCC

2 bytes

00 - 7F

Block check character

(6)

Terminator

1 byte

CR (0Dh)

Message end code

Note: The received user program is stored on the disk in the ASCII code format.

NG Reply (Reply to Request Message 1)

06h

**

**

32h

30h

3*h

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(1)

Communication control character

1 byte

ACK (06h)

Acknowledge

(2)

Communication device number

2 bytes

00

- 1F

Device number 0 through 31

(3)

Command

1 byte

2 (32h)

NG

(4)

01

(30h 31h)

Program capacity error

NG code

2 bytes

02

(30h 32h)

Protect error

04

(30h 34h)

CRC error

(5)

BCC

2 bytes

00

- 7F

Block check character

(6)

Terminator

1 byte

CR (0Dh)

Message end code

Note: NG reply never occurs in response to reply message 2.

MICROSMART

12

MICROSMART COMMUNICATION PROTOCOL

Read User Program in Binary Format

The user program can be read from the PLC to a computer.

When reading a user program to a computer, two request messages must be sent from the computer to the PLC.

Send request message 1 first. After confirming that the returned reply message is an OK reply, send request message 2.

Specify a value larger than the user program capacity selected in the PLC in place of the program capacity in request message 1. Reserve a buffer in the computer to store the data of the specified program capacity temporarily.

Request Messages (Read User Program in Binary Format)

Request Message 1

05h

**

**

31h

52h

70h

3*h

**

**

**

**

**

**

**

**

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(1)

Communication control character

1 byte

ENQ (05h)

Enquiry

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

FF

Device number 255 (all devices)

(3)

Continuation

1 byte

1 (31h)

Continued

(4)

Command

1 byte

R (52h)

Read data

(5)

Data type

1 byte

p (70h)

User program in binary format

0 (30h)

10-I/O

1 (31h)

16-I/O

(6)

CPU module type code

1 byte

2 (32h)

20-I/O transistor output

3 (33h)

24-I/O

4 (34h)

40-I/O

6 (36h)

20-I/O relay output

0000 0000

User program includes data of rung

(7)

comments and tag comments plus

Program capacity

8 bytes

:

function area settings. The function

FFFF FFFF

area occupies 94 bytes.

(8)

BCC

2 bytes

00 - 7F

Block check character

(9)

Terminator

1 byte

CR (0Dh)

Message end code

Request Message 2

05h

**

**

30h

52h

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(1)

Communication control character

1 byte

ENQ (05h)

Enquiry

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

FF

Device number 255 (all devices)

(3)

Continuation

1 byte

0 (30h)

Discontinued

(4)

Command

1 byte

R (52h)

Read data

(5)

BCC

2 bytes

00 - 7F

Block check character

(6)

Terminator

1 byte

CR (0Dh)

Message end code

MICROSMART

13

MICROSMART COMMUNICATION PROTOCOL

Reply Messages (Read User Program in Binary Format)

OK Reply

• Reply Message 1

06h

**

**

31h

3*h

**

**

**

**

**

**

**

**

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(1)

Communication control character

1 byte

ACK (06h)

Acknowledge

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

(3)

Command

1 byte

1 (31h)

OK: Continued

0 (30h)

10-I/O

1 (31h)

16-I/O

(4)

CPU module type code

1 byte

2 (32h)

20-I/O transistor output

3 (33h)

24-I/O

4 (34h)

40-I/O

6 (36h)

20-I/O relay output

0000 0000

User program includes data of rung

(5)

comments and tag comments plus

Program capacity

8 bytes

:

function area settings. The function

FFFF FFFF

area occupies 94 bytes.

(6)

BCC

2 bytes

00 - 7F

Block check character

(7)

Terminator

1 byte

CR (0Dh)

Message end code

• Reply Message 2

06h

**

**

30h

**

**

**

**

**

**

**

**

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(1)

Communication control character

1 byte

ACK (06h)

Acknowledge

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

(3)

Command

1 byte

0 (30h)

OK: Discontinued

(4)

User program

Variable length

(00h) - (FFh)

User program (binary code file)

32,168 bytes max.

(5)

BCC

2 bytes

00 - FF

Block check character

(6)

Terminator

1 byte

CR (0Dh)

Message end code

Note: The received user program is stored on the disk in the binary code format.

NG Reply (Reply to Request Message 1)

06h

**

**

32h

30h

3*h

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(1)

Communication control character

1 byte

ACK (06h)

Acknowledge

(2)

Communication device number

2 bytes

00

- 1F

Device number 0 through 31

(3)

Command

1 byte

2 (32h)

NG

(4)

01

(30h 31h)

Program capacity error

NG code

2 bytes

02

(30h 32h)

Protect error

04

(30h 34h)

CRC error

(5)

BCC

2 bytes

00

- 7F

Block check character

(6)

Terminator

1 byte

CR (0Dh)

Message end code

Note: NG reply never occurs in response to reply message 2.

MICROSMART

14

MICROSMART COMMUNICATION PROTOCOL

Write N Bytes

Data can be written into N-bytes of operands starting with the specified operand number in the PLC.

This command can be used to turn on or off bit operands such as inputs, outputs, internal relays, and shift register bits in units of 8 bits.

This command can also be used to change timer and counter preset values, enter data into data registers, and set calendar/ clock data.

Request Message (Write N Bytes)

05h

**

**

30h

57h

**

**

**

**

**

**

**

**

**

**

**

**

**

**

0Dh

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

Data for 1-byte operand after ASCII conversion

(1)

Communication control character

1 byte

ENQ (05h)

Enquiry

(2)

Communication device number

2 bytes

00 - 1F

Device number 0 through 31

FF

Device number 255 (all devices)

(3)

Continuation

1 byte

0 (30h)

Discontinued

(4)

Command

1 byte

W (57h)

Write data

(5)

Data type

1 byte

See table below.

N-byte designation

(6)

Operand number

4 bytes

See table below.

First operand number to write to

(7)

Data length (n)

2 bytes

00 - C8

Byte count of data to write

200 (C8h) bytes maximum

(8)

Data

2n bytes

0 (30h) - 9 (39h)

Data to write

1 ≤ n ≤ 200

A (41h) - F (46h)

(9)

BCC

2 bytes

00 - 7F

Block check character

(10)

Terminator

1 byte

CR (0Dh)

Message end code

(5) Data type code

(6) Operand number

(Note)

Remarks

X (58h)

Input

0000 - 0307

The least significant digit of the oper-

Y (59h)

Output

0000 - 0307

and number is an octal number (0-7).

M (4Dh)

Internal relay

0000 - 1277, 8000 - 8077

Upper digits are decimal numbers.

R (52h)

Shift register

0000 - 0127

T (54h) Timer (preset value)

0000 - 0099

t (74h) Timer (current value)

0000 - 0099

All four digits of the operand number

C (43h) Counter (preset value)

0000 - 0099

are decimal numbers.

c (63h) Counter (current value)

0000 - 0099

D (44h)

Data register

0000 - 1299, 2000 - 7999, 8000 - 8199

W (57h)

Calendar/clock

0000 - 0006

Note: The valid operand range depends on the CPU module type. For details, see page 48.

Operand numbers for calendar and clock are allocated as listed on the right:

When the range specified by the data type and data length is invalid, the PLC returns an NG reply.

When a data register is designated as a preset value for a timer or counter, data cannot be written into the preset value. To change the preset value, write data into the data register designated as a preset value.

	Calendar/clock	Data
	operand number
	0000	Year
	0001	Month
	0002	Day
	0003	Day of week
	0004	Hour
	0005	Minute
	0006	Second

MICROSMART

15