INP-TN514450c-E
Introduction
Thank you for purchasing the Fuji Digital Temperature Controller.
This document describes how to connect the Micro controller PXG Series (referred to below as "Micro controller") to the personal
computer or programmable controller. It also describes communication specifications for controlling and monitoring the
communications with the micro controller, MODBUS protocol, and address map for the micro controller.
In addition to this document, please make sure to read the Instruction Manual (which comes with the product) and the Operations
Manual (packaged separately).
NOTE
■ Exclusions
The contents of this document may change without prior notice.
Although great care has been taken in the accuracy of this document, Fuji Electric takes no responsibility for loss or indirect
damages caused by mistakes, missing information, or use of information in this document.
– 1 –
Contents
1. Communication Functions
Overview................................................................................4
Connecting to a programmable controller..........................5
Connecting to a personal computer...................................5
2. Specifications
Communication Specifications ..............................................8
RS-485...............................................................................8
PC Loader Interface...........................................................8
3. Connection
Communication Terminal Configuration...............................10
Wiring ..................................................................................11
4. Setting Communication Parameters
List of Setting Parameters...................................................16
Parameter Setting Procedure ..............................................17
5. MODBUS Communication Protocol
Overview..............................................................................20
Message Composition.........................................................21
Station No. .......................................................................21
Function Code..................................................................21
Data Part..........................................................................21
Error Check Code ............................................................21
Slave Response...............................................................22
Function Code..................................................................23
Calculating Error Check Code (CRC-16).............................24
Transmission Control Steps.................................................25
Master Communication Method.......................................25
Explanation ......................................................................25
Precautions when Writing Data...........................................26
7. Address Map and Data Format
Data Format.........................................................................40
Sent Data Format.............................................................40
Internal Calculation Value and Engineering Unit ..............40
Managing the Decimal Point.............................................40
Data during Input Error.....................................................41
Written Data .....................................................................41
Addresses Not Written......................................................41
Internal Calculation Value Data Address Map .....................42
Bit Data (read only): function code [02 (H)]......................42
Word Data (read/write): function code
[03 (H), 06 (H), 10 (H)]......................................................43
Word Data (read only): function code [04 (H)]..................63
8. Sample Program
Sample Program..................................................................68
9. T roubleshooting
Troubleshooting....................................................................78
6.
Command and Transmission Frame Details
Reading Data ......................................................................28
Reading Read-Only Bit Data (Function Code: 02H) ........28
Reading Word Data (Function Code: 03H).......................30
Reading Read-Only Word Data (Function Code: 04H)....32
Writing Data.........................................................................34
Writing Word Data (1 word, function code: 06H)..............34
Writing Continuous Word Data (Function code: 10H) ...... 36
– 2 –
Chapter 1
Communication Functions
Overview – 4
Chapter
1
– 3 –
Overview
Chapter
1
• The micro controller is equipped with communication functions from the RS-485 interface and PC loader interface, which
enables the transmission and reception of data between such devices as the personal computer, programmable controller,
and graphic panel.
• The communication system is composed of a master and slave relationship. Up to thirty-one slaves (micro controllers) may
be connected to one master (such as a personal computer) based on a “single master/multiple slave” method.
• However, the master can only communicate with one slave at a time. Therefore, each slave is specified by the "Station No."
setting.With PC loader communication, only one slave can be connected to one master.
Caution
• In order to have proper communication between master and slave, the transmission data must be in the same format. This
• When using equipment with an RS-232C interface, such as a personal computer, as the master, make sure to use an RS-
• When using PC loader communication, you can use RS-232C communication with the personal computer by connecting the
[RS-232C to RS-485 converter] (Recommended)
Model number/Type Contact URL
KS3C-10 (insulating type) Made by Omron Corporation http://www.omron.co.jp
RC-77 (insulating type) Made by RA Systems Corporation http://www.ras.co.jp
• Systems constructed with the micro controller as slaves do not respond to messages issued by the master
with broadcast queries where the station number is "0".
• PC loader communication is not compatible with the multiple slave method.
document explains how to transmit data using the MODBUS protocol format.
232C to RS-485 converter.
PC loader interface on the bottom of this unit with the PC loader communication cable (RS-232C, model:
ZZPPXH1
TK4H4563) sold separately.
*
– 4 –
Connecting to a programmable controller
Programmable
controller
RS-485
PXG Series
Connecting to a personal computer
Chapter
1
Caution
Personal
computer
RS-232C
RS-232C to RS-485 converter
RS-485
PXG Series
RS-232C
PC loader communication cable
When using the RS-232C to RS-485 converter, check to make sure that the cable is properly connected between the
converter and master. Communication will not work properly if the connection is incorrect.
Also be sure to correctly set the communication settings (such as communication speed and parity) on the RS-232C
to RS-485 converter. Communication will not work properly if the settings are incorrect.
– 5 –
Chapter
1
MEMO
– 6 –
Chapter 2
Specifications
Communication Specifications – 8
Chapter
2
– 7 –
Chapter
2
Communication Specifications
RS-485
Item Specifications
Electrical specifications EIA RS-485 compliant
Communication method Two wire system, half double-bit serial
Synchronous method Asynchronous
Connection status 1:N
Max. no. of connections 31 units
Communication distance Max 500m (total length)
Communication speed 9600bps, 19200 bps
Data format Data length 8 bits
Stop bit 1 bit
Parity None/Even/Odd (Selectable)
Transmission code HEX value (MODBUS RTU mode)
Error detection CRC-16
Insulation Functional insulation for the transmission area and
other areas (withstanding AC 500V)
PC Loader Interface
Item Specifications
Electrical specifications EIA RS232 C
Communication method 3wire system, half double-bit serial
Synchronous method Asynchronous
Connection status 1:1
Station No. 1 (Not to be changed)
Communication speed 9600 bps (Not to be changed)
Data format Data length 8 bits
Stop bit 1 bit
Parity none (Not to be changed)
Transmission code HEX value (MODBUS RTU mode)
Error detection CRC-16
Insulation Non-insulated internal circuit
– 8 –
Chapter 3
Connection
Communication Terminal Configuration – 10
●
Wiring – 11
Chapter
3
– 9 –
Chapter
3
Warning
Do not turn on power until all of the wiring is completely finished.
There is a risk of electrical shock or damage.
Communication T erminal Configuration
■ RS-485 (rear terminal)
PXG4
Terminal
Number
7 RS-485 +
8 RS-485 -
1
7
13
2
8
14
3
9
15
4
10
16
5
11
17
12
6
18
Signal Name
PXG5, PXG9
Terminal
Number
1 RS-485 +
2 RS-485 -
Signal Name
■ PC Loader Interface
(Bottom, φ2.5, three prong miniature jack)
PXG4
PC Loader Interface
PXG5
PC Loader Interface
PXG9
1
2
3
4
5
6
7
8
9
10
11
12
25
26
27
28
29
30
31
32
33
34
35
36
PC Loader Interface
– 10 –
Wiring
■ RS-485
• Please use a shielded twist pair cable. (Recommended cable: KPEV-SB (made by The Furukawa Electric Co., Ltd.))
• The maximum cable length should be 500m. One master and up to thirty-one micro controllers (slaves) can be connected per
circuit.
• Terminate both ends of the circuit with a terminating resistance of 100
• Ground the shielded cable once towards the master side.
Ω (1/2W or more).
Chapter
Master
RS-485 interface
or
RS-485 side of
RS-232C to RS-485 converter
+
–
SG
Terminating resistance
100W (1/2W)
Shielded twist pair cable
3
Slave
+
–
PXG Series
+
–
PXG Series
+
Terminating resistance
100W (1/2W)
• SG does not have to be connected, but it can be used as an effective countermeasure against communication errors due to
noise.
– 11 –
–
PXG Series
•
When using the micro controller in an area where the imposed noise level is expected to exceed 1000V, we recommend using
a noise filter on the master side as seen in the figure below .
[Noise filter] (recommended): ZRAC2203-11 (made by TDK Corporation)
Chapter
3
Programmable controller
or
Personal computer
+ RS-232C to RS-485 converter
Noise filter
RS-485
PXG Series
• If there are problems with EMC during communication, the noise level can be reduced by using a communication cable with a
ferrite core.
Ferrite core (recommended): ZCAT series (made by TDK Corporation)
MSFC series (made by Morimiya Electric Co., Ltd.)
– 12 –
■ PC Loader Interface
• Use the PC loader communication cable (RS-232C) sold separately.
PXG4
PC loader communication cable (RS-232C)
Master side
Personal
computer
etc.
ZZPPXH1
RS-232C
TK4H4563
*
Chapter
3
PXG5
PXG9
Master side
Personal
computer
etc.
D-Sub 9 pin
PC loader communication cable (RS-232C)
ZZPPXH1
RS-232C
D-Sub 9 pin
TK4H4563
*
PXG4 Bottom view
PXG5 Bottom view
Master side
Personal
computer
etc.
PC loader communication cable (RS-232C)
ZZPPXH1
RS-232C
D-Sub 9 pin
TK4H4563
*
PXG9 Bottom view
– 13 –
Chapter
3
MEMO
– 14 –
Chapter 4
Setting Communication Parameters
Chapter
List of Setting Parameters – 16
●
Parameter Setting Procedure – 17
4
– 15 –
Chapter
4
The following settings are required for proper communication between the master and micro controller units.
•
The communication parameters for the master and all of the units must be set the same.
•
During RS-485 communication, all of the micro controllers on a circuit must be set with different "Station No. (STno)" other
than "0 (zero)". (Multiple micro controllers must not have the same "Station No.".)
When using the PC loader interface, settings are not necessary on the main unit (the micro controller).
•
List of Setting Parameters
The setting parameters are shown in the chart shown below. Change the settings using the keys on the front of the micro
controller.
■
RS-485 (main unit side)
Parameter
channel
CoM Ch9
"
(CoM Ch9)
■
Loader interface (main unit side)
Parameter
display symbol
"
STno
"
CoM
"
"
SCC
Parameter name
" (STno)
" (CoM)
" (SCC)
– Data length 8 bits Fixed (cannot be changed) Set the master and all of the slaves with the
– Stop bit 1 bit Fixed (cannot be changed)
Station No. 1 0 to 255 Unit does not respond to communication when 0
baud rate/parity
settings
Communication
permissions
Initial
value
96od 96od (9600 bps/odd)
96Ev (9600 bps/even)
96no (9600 bps/none)
19od (19200 bps/odd)
19Ev (19200 bps/even)
19no (19200 bps/none)
rW r (read only)
rW (read and writable)
Setting range Remarks
is set.
This is the procedure to specify communications
speed and parity check.
Set the master and all of the slaves with the
same settings.
same settings.
The parameters do not need to be set. Set the loader software (master) with the following settings.
•
Communication speed: 9600 bps
•
Parity: none
– 16 –
Parameter Setting Procedure
The following steps explain how to change the settings to station number "3", parity setting "9600bps/none", and communication
permissions "read and writable" as an example.
Press and hold the key to display " Mv1 ".
1
The MV1 of the monitoring screen is displayed.
Press and hold the key to display the setup mode operation
2
menu
("
oPE Ch 1
The communication menu is displayed.
(Note) If your micro controller does not have a communication function, "
model.
Press and hold the key, the use the keys to display
3
" STno ."
The station number is displayed.
Press the key, then use the keys to set station
4
number to "3" when the bottom part of the display begins to blink.
This sets the parameter to "3".
Press the key to confirm the setting.
"), then use the keys to display "
CoM Ch 9
5
Use the keys to select the parity setting (" CoM ").
6
Press the key, then use the keys to set the parity
7
setting to "96no" when the bottom part of the display begins to
blink.
The baud rate/parity setting is set to "9600 bps/none".
".
CoM Ch 9
Chapter
4
" will not be displayed. Please check with your
Press the key to confirm the setting.
8
Use the keys to select the communication permissions
9
(" SCC ").
Press the key, then use the keys to set the
10
communication permissions to "rW" when the bottom part of the
display begins to blink.
"read/write" is selected.
Press the key to confirm the setting.
11
– 17 –
Chapter
4
Press the key to return to the operation mode PV/SV display.
12
Turn the power to the micro controller off and on again.
13
The changes to the communication parameters become effective after
the power turns off and on again.
– 18 –
Chapter 5
MODBUS Communication Protocol
Overview – 20
●
Message Composition – 21
●
Calculating Error Check Code (CRC-16) – 24
●
Transmission Control Steps – 25
●
Precautions when Writing Data – 26
Chapter
5
– 19 –
Overview
The communication system with the MODBUS protocol always operates using a method where the master first sends a command
message and the applicable slave replys with a response message .
The following describes the communication steps.
Master sends the command
message for the slave.
The slave checks whether the station
number in the received message is
the same as its own station number.
When it’s the same When it’s not the same
Chapter
5
The slave runs the command and
sends a response message.
The slave throws out the received
message and waits for the next
command message. (No reply.)
● When the station number in the command message is the same as the unit’s station number
Master Slave
Command Message
Station number is the same
Response Message
● When the station number in the command message is not the same as the unit’s station number
Master Slave
Command Message
Station number is not the same
The master can communicate with an individual slave when multiple slaves are connected on the same circuit by the station
number specified in the master’s command message.
– 20 –
Message Composition
The command message and response message are composed of four parts: the station number, function code, data part, and
error check code. These four parts are sent in that order.
Field name No. of bytes
Station No. 1 byte
Function Code 1 byte
Data Part 2 to 125 bytes
Error Check Code (CRC-16) 2 bytes
The following describes each part of the message.
Station No.
This is the number specifying the slave. Commands can only be processed by slaves that have the same value set in the "STno"
parameter.
Refer to
For more about setting the "STno" parameter, see "Chapter 4,
Setting Communication Parameters" (p. 15).
Function Code
Chapter
5
This code specifies the function for the slave to perform.
Refer to
For more about function codes, see "Function Code" (p. 23).
Data Part
This data is required to run the function code. The composition of the data part is different depending on the function code.
Refer to
See "Chapter 6, Command and Transmission Frame Details"
(p. 27).
The data in the micro controller is assigned a coil number or resistor number. This coil number or resistor number is specified
when the data is read or written through communication.
The coil number or resistor number used by the message employs a relative address.
The relative address is calculated using the following formula.
Relative address = (last four digits of the coil number or resistor number) – 1
(Ex.) When a function code specifies resistor number "40003"
Relative address= (the last four digits of 40003) – 1
= 0002
is used in the message.
Error Check Code
This code detects whether there are errors (changes in the bits) during the signal transmission processes. MODBUS protocol
(RTU mode) uses CRC-16 (Cyclic Redundancy Check).
Refer to
For more about calculating CRC, see Section 5,
"Calculating Error Check Code (CRC-16)" (p. 24).
– 21 –
Chapter
5
Slave Response
■ Normal Slave Response
The slave creates and replies with a response message for each command message. The response message has the same
format as the command message.
The contents of the data part are different depending on the function code.
Refer to
See "Chapter 6, Command and Transmission Frame Details".
■ Irregular Slave Response
If there are problems (such as specification of a nonexistent function code) with the contents of the command message other than
transmission error, the slave creates and replies with an error response message without following the command.
The composition of the error response message uses the value of the function code in the command message plus 80
below.
Field name No. of bytes
Station No. 1 byte
Function Code
+80
H
1 byte
Error Code 1 byte
Error Check Code (CRC-16) 2 bytes
The error code is shown as follows.
Error Code Contents Explanation
01
02
03
H
H
H
Faulty function code A nonexistent function code was specified. Please check the function code.
Faulty address for coil or resistor The specified relative address for the coil number or resistor number cannot be
used by the specified function code.
Faulty coil or resistor number The specified number is too large and specifies a range that does not contain
coil numbers or resistor numbers.
H, as seen
■ No Response
In the following situations, the slave will ignore the command message and not send a response message.
• The station number specified by the command message is not the same as the slave’s specified station number.
• The error check code does not correspond, or a transmission error (such as parity error) is detected.
• The interval between the data comprising the message is empty for more than 24 bit time.
Refer to
See Section 5 "Transmission Control Steps" (p. 25).
• The slave station number is set to "0".
– 22 –
Function Code
For MODBUS protocol, coil numbers or resistor numbers are assigned by the function code, and each function code
only works for the assigned coil number or resistor number.
The correspondence between the function code and the coil number or resistor number is as follows.
Function Code
Coil Number, Resistor Number
Code Function Target Number Contents
Read (continuous) Input relay 1xxxx Read bit data
02
H
03
Read (continuous) Hold resistor 3xxxx Read word data
H
04
Read (continuous) Input resistor
H
Write Hold resistor
H
10
Write (continuous) Retention resistor
H
4xxxx Read/write word data06
The message length for each function is as follows.
[unit: byte]
*
*
*
*
*
Code Contents
02
03
04
06
10
Read bit data (read-only) 8 bit
H
Read word data 60 words
H
Read word data (read-only) 37 words
H
Write word data 1 word 8888
H
Continuously write word data 60 words
H
Assignable
Data Number
1
Command Message Response Message
Minimum Maximum Minimum Maximum
8866
1
1
1
887125
88779
11 129 8 8
1: "Assignable Data Number" above is limited by the data number that the micro controller assigned to the coil number or
address number.
(Excluding function code 06
H
).
Chapter
5
– 23 –