SMC Networks HECR Series Use and care manual

HEC-OM-S008-1.3
PRODUCT NAME
Thermo-con/ Rack Mount Type
MODEL / Series / Product Number
HECR series
Keep available whenever necessary.
This manual is copyrighted and all rights are reserved by SMC Corporation, and may not, in whole or
in part, be copied, photocopied or translated without prior written consent of SMC.
Serial Communication
Manual

History
Version
Cover
Preface
Contents
Chap.1
Chap.2
Chap.3
Chap.4
Chap.5
Chap.6
1.0
1.1
1.1
1.2
1.2
1.2
1.3
1.3
Record of Changes
Version
Contents
Date
1.0
First edition
Aug.2014
1.1
Cover: Change Model No, Add picture
Jun.2015
1.2
4.10, 5.11:Change Communication Format and Examples of Answers from
Thermo-con
May.2017
1.3
5.10.3: Change values in the Explanation
Aug.2023

Preface
Thank you very much for purchasing SMC Thermo-con.
This manual contains description for communication of this product for your full benefit from this product.
Read the operation manual carefully before use of this product, and understand the outline of the product and
safety instructions well. Instructions in the categories, “Danger”, “Warning” and “Caution”, are important for
safety and must be duly followed.
Please contact the following for any question and unclear points regarding the Thermo-con.
SMC Corporation R&D Center
Product Development Division-6
Address: 4-2-2, KINUNODAI,TSUKUBAMIRAI-CITY , IBARAKI-KEN 300-2493, JAPAN
Phone:[phone]
Fax:[phone]
E-mail:[e-mail]
Notice: The content of this manual can be revised without a previous notice.

CONTENTS
1Preparation for Communication .................................................................................................1-1
2Specifications of Communication Method..................................................................................2-1
3Communication Format (same as current HEC series)..............................................................3-1
3.1 Control code used for communication.................................................................................3-1
3.2 Command code list.............................................................................................................3-1
3.3 Communication procedures and format..............................................................................3-2
3.4 Calculation of Check Sum...................................................................................................3-4
4Details of Communication Format..............................................................................................4-1
4.1 Temperature setting (without writing FRAM) .......................................................................4-1
4.2 Reading setting temperature...............................................................................................4-1
4.3 Reading internal sensor......................................................................................................4-2
4.4 Reading external sensor.....................................................................................................4-3
4.5 Reading alarm status..........................................................................................................4-3
4.6 Offset setting (without writing FRAM)..................................................................................4-5
4.7 Reading offset ....................................................................................................................4-5
4.8 Temperature setting (with writing FRAM)............................................................................4-6
4.9 Offset setting (with writing FRAM).......................................................................................4-7
4.10 Communication Format and Examples of Answers from Thermo-con.................................4-8
5MODBUS communication function.............................................................................................5-1
5.1 Precautions for communication...........................................................................................5-1
5.2 Communication specification..............................................................................................5-2
5.3 Setting and checking ..........................................................................................................5-2
5.4 Communication sequence ..................................................................................................5-4
5.5 Message configuration........................................................................................................5-5
5.6 Function codes...................................................................................................................5-7
5.7 LRC....................................................................................................................................5-7
5.8 Explanation of function codes.............................................................................................5-8
5.9 Negative response............................................................................................................5-12
5.10 Register Map....................................................................................................................5-13
5.11 Communication Format and Examples of Answers from Thermo-con...............................5-16
6Troubleshooting.........................................................................................................................6-1

Preparation for Communication
1-1 HECR
1 Preparation for Communication
Make preparation for using communication facility as follows.
1) Turn off the power switch of Thermo-con.
2) Connect communication cable to communication connector (RS-485 or RS-232C) of Thermo-con.
･Use twist pair shield cable as communication cable.
･Connect the host and thermo-con with the straight cable for RS-485 and the cross cable for RS-232C .
･Connect shielded cable of communication cable to communication connector and drop it to
FG(flame ground).
･Connection drawing for communication is shown in the Figures 1-1 and 1-2.
･Length of communication cable for RS-485 shall be limited to around 500[m] in total, and that for
RS-232C shall be 15[m].
･If communication cable for RS-485 is longer, set the terminating resistance (120 ohm) on.
3) Turn on the power switch of Thermo-con.
4) Select communication types for all Thermo-cons. See the operation manual of the details.
5) That’s all for preparation of communication. Then if a communication command from the host
computer is given, each Thermo-con will reply it.
Figure1-1 Communication Connection (RS-485)
Figure1-2 Communication Connection (RS-232C)
Symbol
Pin No
Symbol
FG
Connector
shell
FG
+
1
+
-
9
-
SG
5
FG
Host Computer
RS-485
Thermo-con
RS-485
Symbol
Pin No
Symbol
FG
Connector
shell
FG
RD
2
RD
SD
3
SD
SG
5
SG
RS
Short
CS
Host Computer
RS-232C
Thermo-con
RS-232C

Specifications of Communication Method
HECR 2-1
2 Specifications of Communication Method
・Standards ･･････････････････････････････････････････
・Circuit type ･････････････････････････････････････････
・Communication type ･････････････････････････････
・Communication speed ･････････････････････････････
・Character code ･･･････････････････････････････････
・Parity ･････････････････････････････････････････････
・Start bit ･･･････････････････････････････････････････
・Data length ････････････････････････････････････････
・Stop bit ･･･････････････････････････････････････････
・Block check ･･･････････････････････････････････････
Select RS-485 or RS-232C
Half duplex
Asynchronous
Changeable, 600,1200,2400,4800,9600,19200 bps
ASCII
Select, Nil, even number, odd number
1 bit
Select 7 bit or 8 bit.
Select 1 bit or 2 bit.
Sum check
Note: Values underlined indicate default values at all reset.
It is set to these values when delivered.
Two communication protocols are available.
1) The same communication protocol as the conventional HEC Series thermo-controller
(Refer to Chapter 3 and 4)
2) Modbus communication protocol (Refer to Chapter 5)
In addition to the specification shown in 1), functions of drive mode setting (Drive ON/OFF), control
parameter setting and output ratio display are also added to the product with the Modbus
communication protocol.

Communication Format
3-1 HECR
3 Communication Format (same as current HEC series)
3.1 Control code used for communication
Control code
ASCII code
・”H” of ASCII code indicates hexa code.
ENQ
05H
STX
02H
ETX
03H
ACK
06H
CR
0DH
SOH
01H
3.2 Command code list
Command code (COM)
Contents
31H
Set temperature (without writing FRAM) and read
32H
Read internal sensor
33H
Read external sensor
34H
Read alarm status
36H
Set offset (without writing FRAM) and read
37H
Set temperature (with writing FRAM)
38H
Set offset (with writing FRAM)

Communication Format
HECR 3-2
3.3 Communication procedures and format
The host computer has the initiative of sequence. Sequence always starts from the host computer
and each Thermo-con replies it.
If communication data is processed normally, the Thermo-con returns specified response and if
processing communication data is failed, no response is returned.
When no response is returned to the host computer from the Thermo-con even if waiting for 3 sec.,
resend the data. The Thermo-con returns response after waiting for 50 msec.
For communication of plural number of communication data, wait until the return message is received
from the thermo-con to send the next communication data. It sometimes cannot return the messages
properly when the communication data is received successively.
Selection of Unit Specification
･There are two cases in communication format, which are specifying unit No. and not.
･When one Thermo-con is used, select “without specifying unit” and when two or more Thermo-cons
are used, select “ with specifying unit”.
･When several Thermo-con are used with without specified unit No., correct control is not realized due
to data conflict.
･In the case of use with specified unit No.,ensure to coincide communication No. and each Thermo-con
unit No.
(1) Setting Change
Host →
STX
COM
Data
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
←Thermo-con
ACK
CR
<Specifying unit>
Host →
SOH
UT
STX
COM
Data
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
←Thermo-con
ACK
UT
CR

Communication Format
3-3 HECR
(2) Confirming and reading
Host →
ENQ
COM
Check sum
CR
(H)
(L)
←Thermo-con
STX
COM
Data
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
Host →
ACK
CR
(Possible to omit)
<Specifying unit>
Host →
SOH
UT
ENQ
COM
Check sum
CR
(H)
(L)
←Thermo-con
SOH
UT
STX
COM
Data
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
Host →
ACK
CR
(Possible to omit)
･COM indicates communication command.
･UT indicates unit No. of each Thermo-con. Unit No. is the No. to identify each Thermo-cons when 2 or
more Thermo-cons are linked by communication. Set this No. within 0-F. (UT is the code adding 30H
to unit No. from 30H to 3FH.)
･As for symbols at communication, minus is indicated by “-“ (2DH by ASCII code) and plus is indicated
by “0” (30H by ASCII code).
･In case of setting temperature and offset with communication, data out of set range isn’t memorised. (If
communication format is correct, ACK returns.)
･When writing in FRAM is specified, changed data is memorized in FRAM each time. FRAM is changed
only when data is changed.

Communication Format
HECR 3-4
3.4 Calculation of Check Sum
Calculation range ---------------- From the second byte to ETX
when there is no ETX, add before check sum.
Calculating method---------------Take out the lower 1 byte of the total.
eg.) Set temperature to 30 deg.C (without unit specified)
STX 31H 33H 30H 30H 30H ETX 3FH 34H CR
Total F4H
eg.) Read Thermo-con internal sensor of unit No.2
SOH 32H 05H 32H 36H 39H CR
Total 69H
Note) Check sum is not ASCII code.
Data of UT and Check Sum
Character data
0…9
A
B
C
D
E
F
ASCII
30H…39H
41H
42H
43H
44H
45H
46H
UT and check sum
30H…39H(ditto)
3AH
3BH
3CH
3DH
3EH
3FH

Details of Communication Format
4-1 HECR
4 Details of Communication Format
4.1 Temperature setting (without writing FRAM)
The host computer sets temperature of each Thermo-con. In this command, temperature setting data
is not written in FRAM. This data is invalidated by turning off power.
The setting range is from 10.0 to 60.0 deg.C. As 0.1 deg.C is the minimum unit, the number in the
hundredths place (10-2) should always be 0 (=30H). (When the value at every 0.01deg.C is input, it is
rounded off.)
Host →
STX
31H
Setting data
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
←Thermo-con
ACK
CR
<Specifying unit>
Host →
SOH
UT
STX
31H
Setting data
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
←Thermo-con
ACK
UT
CR
4.2 Reading setting temperature
As 0.1 deg.C is the minimum unit, the number in the hundredths place (10-2) is always 0 (=30H).
Host →
ENQ
31H
Check sum
CR
(H)
(L)
←Thermo-con
STX
31H
Setting data
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
Host →
ACK
CR
(Possible to omit)

Details of Communication Format
HECR 4-2
<Specifying unit>
Host →
SOH
UT
ENQ
31H
Check sum
CR
(H)
(L)
←Thermo-con
SOH
UT
STX
31H
Setting data
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
Host →
ACK
UT
CR
(Possible to omit)
4.3 Reading internal sensor
As the minimum unit is 0.01 deg.C, the value in the hundredths place can be read.
Host →
ENQ
32H
Check sum
CR
(H)
(L)
←Thermo-con
STX
32H
Internal sensor
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
Host →
ACK
CR
(Possible to omit)
Note) 2DH is entered in 101digit “-“is attached to temperature data.
<Specifying unit>
Host →
SOH
UT
ENQ
32H
Check sum
CR
(H)
(L)
←Thermo-con
SOH
UT
STX
32H
Internal sensor
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
Host →
ACK
UT
CR
(Possible to omit)
Note) 2DH is entered in 101digit “-“is attached to temperature data.

Details of Communication Format
4-3 HECR
4.4 Reading external sensor
As the minimum unit is 0.01 deg.C, the value in the hundredths place can be read.
Host →
ENQ
33H
Check sum
CR
(H)
(L)
←Thermo-con
STX
33H
External sensor
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
Host →
ACK
CR
(Possible to omit)
Note) 2DH is entered in 101digit “-“is attached to temperature data.
<Specifying unit>
Host →
SOH
UT
ENQ
33H
Check sum
CR
(H)
(L)
←Thermo-con
SOH
UT
STX
33H
External sensor
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
Host →
ACK
UT
CR
(Possible to omit)
Note) 2DH is entered in 101digit “-“is attached to temperature data.
4.5 Reading alarm status
Host →
ENQ
34H
Check sum
CR
(H)
(L)
←Thermo-con
STX
34H
Data
ETX
Check sum
CR
D1
D2
D3
(H)
(L)
Host →
ACK
CR
(Possible to omit)

Details of Communication Format
HECR 4-4
<Specifying unit>
Host →
SOH
UT
ENQ
34H
Check sum
CR
(H)
(L)
←Thermo-con
SOH
UT
STX
34H
Data
ETX
Check sum
CR
D1
D2
D3
(H)
(L)
Host →
ACK
UT
CR
(Possible to omit)
Data (D2, D2, D3) changes following bit line to ASCII code. (1 is for ON, 0 is for OFF)
D1
23
22
21
20
High temp. cut off alarm ERR12
Low temp. cut off alarm ERR13
Unused
Output failure alarm ERR15
D2
23
22
21
20
Upper temperature limit alarm WRN
Lower temperature limit alarm WRN
Thermostat alarm ERR14
DC power supply failure alarm ERR11
D3
23
22
21
20
External sensor failure alarm ERR18
Internal sensor failure alarm ERR17
During Auto tuning or auto tuning warning ERR19
Flow switch alarm ERR16 or level switch alarm ERR20
When some alarms/warnings go off at the same time, D1 to D3 reaches the added value.
Ex. When the “Upper temperature limit alarm” and the “DC power voltage alarm” go off simultaneously,
D2 will be 23X1+22X0+21X0+20X1=9(=39H).

Details of Communication Format
4-5 HECR
4.6 Offset setting (without writing FRAM)
Set offset of each Thermo-con from host. In this command, offset data loses effect with turning power
to OFF because it isn’t memorized into FRAM.
It can be set at a minimum of every 0.01 deg.C.
Host →
STX
36H
Offset
ETX
Check sum
CR
Symbol
100
10-1
10-2
(H)
(L)
←Thermo-con
ACK
CR
Note) As for symbols, minus is indicated by “-“(=2DH) and plus is indicated by “0”(=30H).
Host →
SOH
UT
STX
36H
Offset
ETX
Check sum
CR
Symbol
100
10-1
10-2
(H)
(L)
←Thermo-con
ACK
UT
CR
Note) As for symbols, minus is indicated by “-“(=2DH) and plus is indicated by “0”(=30H).
4.7 Reading offset
As the minimum unit is 0.01 deg.C, the value in the hundredths place can be read.
Host →
ENQ
36H
Check sum
CR
(H)
(L)
←Thermo-con
STX
36H
Offset
ETX
Check sum
CR
Symbol
100
10-1
10-2
(H)
(L)
Host →
ACK
CR
(Possible to omit)
Note) As for symbols, minus is indicated by “-“(=2DH) and plus is indicated by “0”(=30H).

Details of Communication Format
HECR 4-6
<Specifying unit>
Host →
SOH
UT
ENQ
36H
Check sum
CR
(H)
(L)
←Thermo-con
SOH
UT
STX
36H
Offset
ETX
Check sum
CR
Symbol
100
10-1
10-2
(H)
(L)
Host →
ACK
UT
CR
(Possible to omit)
Note) As for symbols, minus is indicated by “-“(=2DH) and plus is indicated by “0”(=30H).
4.8 Temperature setting (with writing FRAM)
The host computer sets temperature of each Thermo-con. In this command, temperature setting data
is written in FRAM.
The setting range is from 10.0 to 60.0 deg.C. As 0.1 deg.C is the minimum unit, the number in the
hundredths place (10-2) should always be 0 (=30H). (When the value at every 0.01deg.C is input, it is
rounded off.)
Host →
STX
37H
Setting data
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
←Thermo-con
ACK
CR
<Specifying unit>
Host →
SOH
UT
STX
37H
Setting data
ETX
Check sum
CR
101
100
10-1
10-2
(H)
(L)
←Thermo-con
ACK
UT
CR