Chino SE Series User manual

Please make sure that this manual is handed to the final user of the instrument.
INST.№ INE-301B
COMMUNICATIONS
INTERFACES
SE series FIELD SCANNER
Retain this manual apart from the
instrument and in an easily accessible.
SE3000

Contents
INTRODUCTION 1
1 GENERAL 2
1.1 RS-232C Communications Interface
1.2 RS-422A/485 Communications Interface
2COMMUNICATIONS PARAMETERS 2
3 SETTINGS OF SWITCHES 3
3.1 Instrument number
3.2 Communications port
3.3 Communications type
4 CONNECTIONS 4
4.1 Connection Precautions
4.2 Communications Cables
4.3 RS-232C Connections
4.4 RS-422A/485 Connections
5MODBUS PROTOCOL 11
5.1 Message Transmission Modes
5.2 Data Time Interval
5.3 Message Configuration
5.4 Creating a Message
5.5 Function Code
5.6 Processing in Abnormal Status
5.7 Table of Reference
5.8 Range number list
6
SAMPLE PROGRAM (For RTU Protocol) 50

－1－
INTRODUCTION
This instruction manual describes the specifications and operation of three built-in communications
interfaces (RS-232C, RS-422, and RS-485) of the SE3000 series field scanner.
The explanation of these interfaces is partly same. However, their differences are explained separately in
[For RS-232C] and [For RS-422A and RS-485]. Please read the required part carefully.
1. Other Instruction Manuals to be consulted
This instruction manual is for the communications interface only. For the installation, running and operation
of the SE3000, please refer to the following instruction manuals:
1. SE3000 series field scanner (Manual No. INE-300)
2. SC8-10 Line Converter (Manual No. INE-39)
* For your personal computer, refer to the instruction manual attached to it.
2.Caution Display
This manual contains explanation of precautions. Follow these precautions when operating and handling
the communications interfaces, otherwise the instrument maybe damaged, resulting in deterioration in its
performance, or operation failures may also occur.
(1) The contents of this manual are subject to change without notice.
(2) The contents of this manual have been prepared professionally.
However, if you have any questions, or notice of error or an omission of
descriptions found in this manual, please contact your nearest agent of
CHINO Corporation.
(3) CHINO Corporation is not responsible for any results influenced by the
operation of this communications interface, irrespective of item (2)
above.
Caution

－2－
1GENERAL
Three types of communication interfaces (RS-232C, RS-422A and RS-485) are available in the SE3000
series field scanner, and receiving of measured data and settings of various parameters can be executed
by a personal computer (PC).
1.1 RS-232C Communications Interface
The RS-232C is the data communications standard being set and issued by EIA (Electronic Industries
Association) in the USA and JIS C 6361 in Japan.
This standard is a basic interface between MODEM and connected data terminal units, and specifies
electrical and mechanical specifications only. Most of the RS-232C communications interface is being used
for personal computers and industrial instruments such as the SE3000 series field scanner do not
completely conform to this standard at present, and have different signal wire numbers, connectors to those
specified in the standard. Also, since this standard does not specify any software parts, or so-called [data
transmission procedures], units having the RS-232C communications interface can not be interconnected
with each other unconditionally. With these reasons, users must survey and check the specifications and
transmission procedures in advance of units being connected. However, if the counter unit is a personal
computer or a similar device that can optionally program the specifications, all the units can be combined by
having proper programs prepared by a program designer.
1.2 RS-422A/485 Communications Interface
The RS-422A and RS-485 communications interface can communicate with multiple SE3000 series field
scanners (up to 31 sets) in parallel by signals conforming to RS-422A and RS-485.
There are few personal computers that provide RS-422A or RS-485 communications interface. However,
since these communications interfaces are characterized with serial communications, these are easily
connectable to the personal computer having the RS-232C communications interface by using an RS-422A
or RS-485 ⇔RS-232C signal converting unit. A line converter (Model SC8-10: sold separately) is available
for RS-422A and RS-485 ⇔RS-232C signal conversion at CHINO.
For the difference between RS-422A and RS-485 communications interfaces, the RS-422A needs four
signal cables, while RS-485 needs only two signal cables.
2COMMUNICATIONS PARAMETERS
The communications parameters of the SE3000 series field scanner are as follows. The parameters
marked with * are defaults.
* Half-duplex (polling selecting system)
* Protocol: MODBUS protocol ( *RTU mode / ASCII mode )
* Transmission speed: 19200, *9600 bps selectable
* Start bit: 1 bit
* Data length: 7 bits / *8 bits selectable (depending on transmission mode)
* Parity bit: Even / Odd / *Disabled selectable (depending on transmission mode)
* Stop bit: *1 bit / 2 bits selectable (depending on transmission mode)
* Transmission code : *Binary / ASCII (depending on transmission mode)
* Error check: *CRC-16 / LRC (depending on transmission mode)
* External units given priority for communications
* Data transmission procedure: None
* Signals in use: Transmitted and received data only (no control signal in use)
The change of the communications parameters is executed by the “parameter programming softwar
e
package (PASS – Separate purchase is required.)”.
Caution

－3－
3SETTINGS OF SWITCHES
Before mounting and connections, set the switch No. 1 (SW.1) at the front of instrument and the switch No. 2
(SW.2) up side. Make sure to confirm the settings even if you use the defaults.
3.1 Instrument number 3.2 Communications port
SW1-6
OFF(default) ON
COM (default) ENG
SW1-1 SW1-2 SW1-3 SW1-4 SW1-5 Number
OFF OFF OFF OFF OFF １
(default)
ON OFF OFF OFF OFF １
OFF ON OFF OFF OFF ２
ON ON OFF OFF OFF ３
OFF OFF ON OFF OFF ４
ON OFF ON OFF OFF ５
OFF ON ON OFF OFF ６
ON ON ON OFF OFF ７
OFF OFF OFF ON OFF ８
ON OFF OFF ON OFF ９ 3.3 Communications type
OFF ON OFF ON OFF １０
ON ON OFF ON OFF １１
OFF OFF ON ON OFF １２
ON OFF ON ON OFF １３
OFF ON ON ON OFF １４
ON ON ON ON OFF １５
OFF OFF OFF OFF ON １６
ON OFF OFF OFF ON １７
OFF ON OFF OFF ON １８
ON ON OFF OFF ON １９
OFF OFF ON OFF ON ２０ SW2
ON OFF ON OFF ON ２１ Front side Back side (Default)
OFF ON ON OFF ON ２２ (Terminals side) (DIN rail side)
ON ON ON OFF ON ２３ RS232C RS422A/485
ON OFF OFF ON ON ２５
OFF ON OFF ON ON ２６ For the connection with the BR, change to
ON ON OFF ON ON ２７ RS422A/485.
OFF OFF ON ON ON ２８
ON OFF ON ON ON ２９
OFF ON ON ON ON ３０
ON ON ON ON ON ３１
Note) Don't duplicate the settings of each instrument.
Mounting place of SW.1
Change by a small screwdriver.
Mounting place of SW.2
422A/485
DIN rail side
Up side o
f
instrument
232C
Change with a sharp tipped material.
Terminal side
The engineering port is used for th
e
configuration by the parameter programming
software package (PASS – Separat
e
purchase is required.). Communications with
PC cannot be executed when changed to th
e
engineering port.
Engineering port
For parameters and other settings by the paramete
r
programming software package (PASS – Separat
e
purchase is required.), it is necessary to change t
o
the engineering port.

－4－
4CONNECTIONS
4.1 Connection Precautions
4.1.1 Communications Terminals
Disposition of terminals are different with each communications interface.
4.1.2 Total extension of RS-422A/485 communications cable is up to 1.2km.
The wiring interval between each instrument is option, but the total extension distance of cable is within
1.2km.
(Line converter the final end of SE3000 series fields scanner)
Total extension of cable: Within 1.2km
Line converter SE3000 series field scanner
RS-232C Terminals
ＳＤ
ＲＤ
ＳＧ
RS-422A/RS-485
Terminal
s
ＳＤＡ
ＳＤＢ
ＲＤＡ
ＲＤＢ

－5－
4.1.3 Prevention of noise
Separate the communications cable from drive power cables and other communications cables more than
50cm so as not to be affected by noises.
4.1.4 Crimp style terminals
Falling off of connections is one of communications
failures. Terminate the communications cable with an
[O] or [Y] type crimp style terminal having an
insulation sleeve. (The terminal screws of SE3000
series field scanner and line converters are
M3.5mm.)
4.1.5 Mount an insulation resistor
For using the RS-422A or RS-485 communications interface, mount a 100 Ωresistor to the SE3000
scanner connected at the final end. (For details, see Section 4.4)
[A general metal film resistor can be used. The resistor (sold separately) is available at CHINO.]
4.1.6 Number of SE3000 series field scanner connectable
For RS-232C: 1 set
For RS-422A or RS-485: Up to 31 sets
Insulation sleeves
O type crimp terminal
3.7 more
8 or less
3.7 more
8 or less
Y type crimp terminal
Insulation sleeves
(mm)

－6－
4.2 Communications Cables
Make ready cables dedicated to communications before performing connection. Dedicated communications
cables (sold separately) are available at CHINO.
4.2.1 Communications cables for RS-232C
(1) Connection between a PC (with 9-pin terminal) and the SE3000 series field scanner and between a PC (with
9-pin terminal) and a line converter.
Cable 9-pin connector RS-232C cable with O-shaped crimp terminal
Style
Internal wiring
Type code RZ-CRS6
Cable length of 1 to 15 m (To be specified)
(2) Connection between a PC (with 25-pin terminal) and the SE3000 series field scanner and between a PC(with
25-pin terminal) and a line converter.
Cable 25-pin connector RS-232C cable with O-shaped crimp terminal
Style
Internal wiring
Type code
RZ-CRS2□□
Cable length of 1 to 15 m (To be specified)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
RD
SD
SG
25-pinconnector
to a PC
To the SE3000 series field
scanner or a line converter
In case of NEC's PC98 series (except NX)
SD
RD
SG
SD
RD
SG
1
2
3
4
5
6
7
8
9
RS-232C cable (max. length of 15 m)
RD
SD
SG
9-pin connector
to a PC
To the SE3000 series field
scanner or a line converter
RS-232C cable
(
max. len
g
th of 15 m
)

－7－
4.2.2 Communications cables for RS-422A
(1) Connection between a line converter and the SE3000 series field scanner
Cable
O-shaped crimp terminal RS-422A cable with O-shaped crimp terminal (for line converter)
Style
The cable consists of a pair of twisted dual-core CVVS wires with SG (signal
grounding) wire at both ends. Cut off the SG wire on the line converter side because
this has no SG terminal.
Internal wiring
Type code RZ-CRA2
Cable length of 1 to 99 m (To be specified)
(2) Connection between the SE3000 series field scanner and the SE3000 series field scanner
Cable
O-shaped crimp terminal RS-422A cable with O-shaped crimp terminal (for parallel connection)
Style
The cable consists of a pair of twisted dual-core CVVS wires with SG (signal
grounding) wire at both ends.
Internal wiring
Type code RZ-CRA1
Cable length of 1 to 99 m (To be specified)
RDA
RDA
RDB
RDB
SDA
SDA
SDB
SDB
SG SG
To a line converter To the SE3000 series field
scanner
RDA RDA
RDB RDB
SDA SDA
SDB SDB
SG SG
To the SE3000 series field
scanner
To the SE3000 series field
scanner
RDB
RD
A
SD
A
SD
B
SG
RDB
RDA
SDA
SDB
SG
RD
B
RD
A
SD
A
SDB
SG
RDB
RDA
SDA
SDB
SG

－8－
4.2.3 Communications cables for RS-485
(1) Connection between a line converter and the SE3000 series field scanner
Cable
O-shaped crimp terminal RS-485A cable with O-shaped crimp terminal (for line converter)
Style
The cable consists of a twisted dual-core CVVS wires with SG (signal grounding) wire
at both ends. Cut off the SG wire on the line converter side because this has no SG
terminal.
Internal wiring
Type code RZ-LED (for line converter)
Cable length of 1 to 200 m (To be specified)
(2) Connection between the SE3000 series field scanner and the SE3000 series field scanner
Cable
O-shaped crimp terminal RS-485 cable with O-shaped crimp terminal (for parallel connection)
Style
The cable consists of a twisted dual-core CVVS wires with SG (signal grounding) wire
at both ends.
Internal wiring
Type code RZ-LEC (For parallel connection)
Cable length of 1 to 200 m (To be specified)
RD
A
RD
B
SG
SA
SB
SG
To a line converter To the SE3000 series field
scanner
RD
A
RDB
SG
SA
SB
SG
S
A
S
B
SG
SA
SB
SG
To the SE3000 series field
scanner
To the SE3000 series field
scanner
S
A
SB
SG
SA
SB
SG

－9－
4.3 RS-232C Connections
The SE3000 series field scanners use three control signals of Send(SD), Receive(RD), Signal ground (SG)
only. Since general personal computers are controlled by control signals, the computer does not function by
only connecting three signal cables without wiring processing inside the connectors. Wiring processing
depends upon the control signals being controlled by the personal computer. For details, read the
instruction manual for your personal computer.
The RS-232C cable length is restricted to be within 15m. The connection for NEC PC98 series
9-pin connector is in [Connection sample 1] and for the 25-pin connector is in [Connection sample 2].
Caution!
[Connection
Exam
p
le 1
]
[Connection
Example 2]
25
1 2 3 4 5 6 7 8 9 10 11 12 13
14 15 16 17 18 19 20 21 22 23 24
SD RD SG
RS
CS
DR
ER
25-pin connector
(PC-98 series)
25
1 2 3 4 5 6 7 8 9 10 11 12 13
14 15 16 17 18 19 20 21 22 23 24
SD
RD SG
RS
CS
DR
ER
CD
25-pin connector
25
1 2 3 4 5 6 7 8 9 10 11 12 13
14 15 16 17 18 19 20 21 22 23 24
SD RD SG
RS
CS DR
ER
CD
25-pin connector
SD RD SG
RS
CS
DR
ER
1 2 3 4 5
6 7 8 9
9-pin connector
(PC-98 series/IBM-PC/AT)
SE3000 series field scanner SE3000 series field scanner
SE3000 series field scanner SE3000 series field scanner
[Connection
Example 4]
[Connection
Example 3]
Communications
Cable
RZ-CRS6□□
Communications
Cable
RZ-CRS2□□

－10－
4.4 RS-422A, RS-485 Connections
This paragraph describes the method of connecting the RS-422/485 communications interface to the
personal computer by using the line converter (Model SC8-10: sold separately). Since the line converter
and the personal computer use three control signals of Send, Receive and Signal ground only, the wiring
processing inside the connectors is necessary in the same way as in RS-232C connections.
[For details, read the instruction manual for line converter (Model SC8-10: sold separately).]
RD
SD
SG
RDA
RDB
SDA
SDB
1
2
3
4
5
6
7
8
1 2 3 4 5
6 7 8 9
SDA SDB RDA RDB
SDA SDB RDA RDB
SDA SDB RDA RDB
SE3000
series field
scanner
SE3000
series field
scanner
SE3000
series field
scanner
Line converter
9-pin connector
(The wiring processing inside th
e
connector is necessary.)
9-pin connector
(The wiring processing inside th
e
connector is necessary.)
Termination resistor 100Ω
SE3000
series field
scanner
1 2 3 4 5
6 7 8 9
Line converter
Termination resistor 100Ω
In case of RS-422A
In case of RS-485
RD
SD
SG
RDA
RDB
SDA
SDB
1
2
3
4
5
6
7
8
Communications Cable
RZ-CRA1□□
Communications Cable
RZ-CRA2□□
Communications Cable
RZ-CRS6□□
Communications Cable
RZ-LEC□□□
Communications Cable
RZ-CRS6□□
Communications Cable
RZ-LED□□
ＳＤＡ
ＳＤＢ ＲＤＡ ＲＤＢ
SE3000
series field
scanner
ＳＤＡ
ＳＤＢ ＲＤＡ ＲＤＢ
SE3000
series field
scanner
ＳＤＡ
ＳＤＢ ＲＤＡ ＲＤＢ
Receiving
data
SDA
SDB
Sending
data
RDA
RDB
Inside circuit
Please do not connect
SG line to FG terminal
or the protective conductor
terminal of instrument.
Caution!
Please do not connect
SG line to FG terminal
or the protective conductor
terminal of instrument.
Caution!

－11－
5MODBUS PROTOCOL
Basic Procedures of Communications and Precautions
Attention!
1. A data request immediately after turning the power on will lead to an error.
The SE3000 series field scanners are always ready for communications. They are at anytime
responsive to data requests from personal computers. However, immediately after turning the power on,
the recorders do not deliver a normal response until the data of all channels is ready. It takes, for
instance, about 8 seconds until all the data becomes ready for the SE3000 field series scanners for 48
points. When receiving a data request during this period, the SE3000 field series scanners return the
error message No.12 (set mode error).
2. Take care of command re-transmission as there is no control signal line in use.
Since the SE3000 series field scanners' serial interfaces communicate freely without using any control
line, a reception failure may occur under some conditions. Exercise care when resending a command.
3. Don't disconnect or short any cables or instruments constituting the serial
interface, or turn the power on or off during communications.
Don't disconnect or short any cables or instruments constituting the serial interface, or turn the power on
or off during communications, or the operation may stop or lead to a malfunction. When this happens, all
the components of the serial interface must be reset to repeat the operation from the beginning.
4. Send the next command after making sure that the communications drive has
been turned off.
For RS422A/RS-485 communications interface, multiple instruments are connected to the same
communications line, only one instrument, of which instrument No. is specified by the PC, drives the
communications line. The communications drive is turned off at a certain time (approx. 5 msec) after
sending the last character so that all the characters are safely received by the personal computer. If the
PC sends a command to the next unit before the communications drive is turned off, signals interfere
with each other resulting in some communication failure. Exercise caution when you use a high-speed
PC.

－12－
5.1 Message Transmission Modes
There are two modes of message transmission, RTU (Remote Terminal Unit) and ASCII, which can be
selected by key programming.
(Table 1 Comparison between RTU and ASCII modes)
Item RTU mode ASCII mode
Interface RS-232C, RS-422A､RS-485
Communications system Half-duplex start-stop synchronization
Transmission speed 9600，19200bps
Character code Binary ASCII
Vertical Parity
Error check Horizontal CRC-16 LRC
Start bit 1 bit
Data bit 8 bits 7 bits, 8 bits (Note)
Parity bit Disabled, even, odd Disabled (Note), odd, even
Character
Configuration
Stop bit 1,2 bit
Message start code None : (Colon)
Message stop code None CR, LF
Data time interval 28 bit-time or less 1 second or less
(Note) 8 bits are also available at SE3000 series field scanners.
(Note) "Parity disabled" is not available when data bits are 7.
5.1.1 Transmitted data
The RTU-mode data is transmitted in binary numbers. In ASCII mode, the 8-bit binary data of RTU is
separated into higher-order 4 bits and lower-order 4 bits and both are turned into characters (0 - 9, A - F).
Example) RTU mode
ASCII mode
67H 36H (“6”)
89H 37H (“7”)
ABH 38H (“8”)
39H (“9”)
41H (“A”)
42H (“B”)
Length of the RTU-mode message is half that of an ASCII-mode message, ensuring a more efficient
transmission.
5.1.2 Message frame configuration
The RTU-mode data consists only of a message section.
The ASCII mode data consists of a start character [ ": (colon, 3AH)], a message and a stop character [("CR
(carriage return, 0DH) + LF (line feed, 0AH) ].
RTU ASCII
Message
：Message CR LF
The ASCII mode has the advantage of easier troubleshooting because its message has a start character
[ : ].

－13－
5.2 Data Time Interval
In RTU mode: Below 28 bit-time (2.8 msec. at 9600 bps, 1.4 msec. at 19200 bps)
In ASCII mode: Below 1 second
When sending a message, keep the time interval of data constituting one message not longer than the time
specified above. When the time interval of data is longer than the above, the receiver unit (i.e., this scanner)
recognizes that the data transmission from the sending unit is complete, so that the subsequent data is
processed as an abnormally received message.
While the message characters must be consecutively sent in RTU mode, the ASCII modes allows for a
maximum interval of 1 second between characters, making it possible to use a master unit (PC) with a
relatively slow processing speed.
5.3 Message Configuration
The MODBUS message has the following configuration in both RTU and ASCII modes.
Slave address
Function code
Data
Error check
5.3.1 Slave address
The slave address can be programmed in advance by key operation within a range between 1 and 31. The
master unit usually communicates with one slave unit. While messages from the master unit are received
commonly by all the units in connection, only the slave unit corresponding to the slave address included in
the command message responds to the message sent.
In case of the RS-232C, send "1" as a slave address. This recorder also sends a slave address of "1".
The slave address "0" is used for a message from the master unit addressed to all the slave units (broadcast
message). The slave units do not send a response back to the master unit.
5.3.2 Function code
Function codes refer to the functions to be executed by the slave units. The data is generally classified as
follows. Refer to the reference table for details.
(1) Digital parameters: Parameters are mainly for changing the functions.
(2) Digital input data: Parameters are such as input data status and alarm status.
(3) Analog parameters: Information on various parameters. Numerical values should be kept within
the 16-bit range between -32768 and 32767 (see the reference table for
details). If the data cannot be expressed with 16-bit numbers, use floating
data for reading and writing.
(4) Analog input data: Information on measured data and instrument specifications. Numerical
values within the range of 16-bits are delivered as an output. If the data
cannot be expressed with 16-bit numbers, use floating data (floating-point
data) for reading.
(5) Floating data: If the data cannot be expressed with the numerical values within the 16-bit
range (between –32768 and 32464), use floating data for its expression.
This expression is not available in the standard MODBUS.

－14－
(Table 2. Function code table)
Code Functions Unit
MODBUS original functions (ref.)
01 Read digital (ON/OFF) parameter 1 bit Read coil status
02 Read digital input data 1 bit Read input relay status
03 Read analog parameter 16 bit Read hold register contents
04 Read analog input data 16 bit Read input register contents
05 Write digital parameter 1 bit Change single coil status
06 Write analog parameter 16 bit Write single hold register
08 Send received data (for diagnosis) Loop-back test
16 Write two or more analog parameters
Write into two or more hold registers
70 Read floating data Arbitrary command to vendor
71 Write floating data Arbitrary command to vendor
5.3.3 Data section
Data configurations depend on the function codes. A master request consists of the code number of the data
to be read or written (Relative No. to be calculated from the Reference No. described below) and the number
of data pieces. Response from slave units consists of data responsive to the request.
Every MODBUS basic data consists of 16-bit integers, with or without codes depending on individual data. It
is thus configured as integers with their decimal places assigned to separate addresses, or normalized with
the upper and lower limits specified by the scale with fixed decimal places. The SE3000 series field scanners
employ the system of assigning the decimal places to separate addresses. Numerical data that cannot be
expressed with 16-bit integers can be read and written using floating data. Note that floating data expression
is not available in the standard MODBUS.
5.3.4 Reference Nos.
Data in the SE3000 series field scanners have "Reference No." assigned to each of them which is required
for reading and writing the data. The data in the SE3000 series field scanners are classified into "Digital
parameter", "Digital input data", "Analog input data", "Analog parameter" and "Floating (floating-point) data"
depending on their type. The Nos. in the message are designated by the "Relative Nos." corresponding to
the Reference Nos.
(Table 3. Reference Nos. and Relative Nos.)
Data type Reference No. Relative No.
MODBUS original (for reference)
Digital parameter 1 to 10000 Reference No. – 1 Coil
Digital input data 10001 to 20000 Reference No. – 10001 Input relay
Analog input data 30001 to 40000 Reference No. – 30001 Input register
Analog parameter 40001 to 50000 Reference No. – 40001 Hold register
Floating data 50001 to 60000 Reference No. – 50001
Example) Relative No. of Channel 1 data at "Reference No. 30101" is "100.

－15－
(Table 4 Quick search table for Reference Nos.)
Data type Parameters Reference No Corresponding
function code
Reference
table
Digital parameter Temperature unit 25 01(READ)
05(WRITE) Section 5.7.1
Digital input data Measured data status
Alarm status 10001 to 10500 02(READ) Section 5.7.2
Analog input data Instrument information
Measured data
30001 to 30050
30101 to 30200 04(READ) Section 5.7.3
Analog parameter
Programming for all channels
Alarm deadband
Programming for each channel
Range
Subtract
Scale
Burnout
Engineering unit
Tag
Alarm
Math
40001 to 40100
40101 to 42500
03(READ)
06(WRITE)
16(WRITE)
Section 5.7.4
Floating data
Measured data
Programming for each channel
Range
Scale
Alarm value
Math
50101 to 50150
50301 to 51500
70(READ)
71(WRITE) Section 5.7.5

－16－
5.3.5 Error check
Error check for transmission frames is different between the transmission modes.
RTU mode: CRC-16
ASCII mode: LRC
5.3.5.1 Calculation of CRC-16
In the CRC system, the information to be transmitted is divided by a generating polynomial, the resulting
remainder being added to the end of the data. The generation polynomial is as follows.
1+X
2+ X15 + X16
The data from its slave address to its end is calculated in the following procedure.
1) Initialize the CRC-16 data (assumed as X) (= FFFFH)
2) Exclusive logical sum (EX - OR) between data 1 and X X
3) Shift X one bit to the right X
4) When a carry is generated, take A001H and EX-OR. If not, go to 5). X
5) Repeat 3) and 4) until shifting 8 times.
6) EX-OR between the next data and X X
7) Same as 3) to 5)
8) Repeat up to the last data
9) Create a message in the sequence from lower to upper orders of the calculated 16-bit data (X).
Example) Since CRC-16 is 1241H for the data 01H 07H , the error check data will be 41H 12H.
Reference: CRC-16 Calculation Program
10 D(1) = &H2 : D(2) = &H7 : N = 2
20 GOSUB *CRCMAKE
30 END
40
100 *CRCMAKE
110 CRC = &HFFFF
120 FOR I = 1 TO N
130 CRC = CRC XOR D(I)
140 FOR J = 1 TO 8
150 CY = CRC AND &H1
160 IF CRC < 0 THEN P = &H4000 ELSE
P=0:GOTO180
170 CRC = CRC AND &H7FFF
180 CRC = CRC 2
190 CRC = CRC OR P
200
IF CY = 1 THEN CRC = CRC XOR
&HA001
210 NEXT J
220 NEXT I
230
IF CRC < 0 THEN P = &H80 ELSE
P=0:GOTO250
240 CRC = CRC AND &H7FFF
250 C1 = CRC AND &HFF
260
C2 = ( CRC AND &H7F00 ) 256
270 C2 = C2 OR P
280 D (N+1) = C1 : D(N+2) = C2
290 RETURN

－17－
5.3.5.2 Calculation of LRC
The data from its slave address to its end is calculated in the following procedure.
1) Create a message in RTU mode.
2) Add the start (slave address) to end of the data. -- X
3) Complement X (bit reverse) -- X
4) Add 1 (X = X + 1)
5) Add X as an LRC to the end of the message.
6) Convert the whole data to ASCII characters.
Example) For the data 02H 07H , LRC is F7H which will be 02H 07H E7H as a binary message,
so that the ASCII message will be 30H 32H 30H 37H 46H 37H .
5.3.6 Precautions on data processing
(1) Since the measured data and decimal places are assigned to separate numbers, it is necessary to use
both parts of the information when playing back the data.
(2) Since data is accessible (changeable) one by one, care must be taken when programming related data,
for instance when initializing related data by changing the range number. Processing details are given in
the Reference No. list.
(3) Read or write the data within the range of Reference Nos. specified. If data is written on any Reference
No. not specified, it is likely to affect the proper operation of the instruments.
(4) While it is possible to write data on two or more discreet Reference Nos., a start number with Reference
No. not specified will result in an error (error No. 02H).
(5) When reading two or more Reference Nos., the data with Reference No. not specified becomes "0".
(6) When an error is detected during writing on two or more Reference Nos., all the programming becomes
invalid.

－18－
5.4 Creating a Message
A message consists of (1) Slave address, (2) Function code, (3) Data section and (4) Error check code. (See
Section 5.3)
The message readable or writable at one time is within the following range.
Data type Number of data pieces
Floating data 60
Other than floating data 120
How to create a message will be described by an example given below.
Example) Reading a measured data for SE3000 series field scanners Channel 1 with "slave address 02".
5.4.1 RTU mode message
(1) Slave address : 02 ( 02H )
(2) Function code : 04 ( 04H )
The data type is "Read analog input data (read input register contents)". When the function code is "04",
specify the “data's Relative No. by 2 bytes" and the "number of data pieces by 2 bytes" to be read from the
data section. (See Section 5.5. See Section 5.5.4 for "Function code: 04".)
* It is necessary to make sure of the number of bytes of data.
(3) Data section :
Starting Relative No. 100 ( 00H 64H ) and Number of data pieces 2 ( 00H 02H )
Measured data (analog input data) are stored in Reference Nos. "30001 to 40000" (See Table 3 in Section
5.3.4). The reference table shows that the integer part of CH1 is stored in "30101" and the decimal place in
"30102". (See Section 5.7. See Section 5.7.3 for reading the measured data.)
The Relative No. of the starting "Reference No. 30101” is 30101 - 30001 = 100 that can be expressed by 2
bytes " 00H 64H ".
The number of data pieces to be read is "2" of the integer part of CH No.1 and the decimal place, which
can be expressed by " 00H 02H " in 2 bytes
(4) Error check: 2730H calculated with CRC-16 ( 30H 27H )
Error check in RTU mode is calculated with CRC-16. (See Section 5.3.5.1)
The data in the core message is:
" 02H 04H 00H 64H 00H 02H " according to (1) to (3), whose CRC-16 is 2730H.
Error check data is therefore 30H 27H .
(5) Message: 02H 04H 00H 64H 00H 02H 30H 27H
Create a message according to the message configuration. (See Section 5.3)