INSTRUCTION

MANUAL FOR GCS-300 COMMUNICATION[OPTION CODE: C5]№GCSC3E2 2008.05

To prevent the accidents by mishandling of this controller, please arrange to
give this manual into the hands of the operator who actually uses our products.

Warning
Turn the power supplied to the instrument OFF before wiring or checking.
If working or touching the terminal on the power ON status, there isa possibility of Electric Shock which can cause severe injury or death.

1. System configuration
1.1 RS-485 Multi-point connection [Option code: C5]
Hostcomputer
RS-485
GCS-300№ 0

GCS-300№ 2

GCS-300№ 1

GCS-300№ 30[Fig. 1.1-1]
Hostcomputer
RS-232C

IF-300232C⇔485
Interface

RS-485

GCS-300№ 0

GCS-300№ 1

GCS-300№ 30

GCS-300№ 1

GCS-300№ 30[Fig. 1.1-2]
Hostcomputer
RS-422A

IF-100422A⇔485
Interface

RS-485

GCS-300№ 0[Fig. 1.1-3]

1.2 When executing setting value digital transmission by option C5.
PC-900RS-485

GCS-300

GCS-300

GCS-300

Option: C5

Option: C5

Option: C5

Maximum 31 units of GCS-300[Fig. 1.2-1]･ The main setting value of PC-900 [option code: SVTC] can be transmitted
in digital to the GCS-300 [option code: C5].
･ Fit the transfer rate of PC-900 and GCS-300 when transmitting the main
setting value in digital, and designate Lock 3 in Setting value lockdesignation of the GCS-300.
･ Maximum 31 units of GCS-300 are connectable to one PC-900.

z Notices when using the setting value digital transmission [Option code: SVTC]･ Memory life of the GCS-300 is approximately 1 000 000 (one million) times
in writing. Therefore when frequently writing the command, designate Lock 3
in Setting value lock of the GCS-300, since it has no relation to memory life.
If the Lock 3 is not designated, it writes the memory every time thesetting command is sent, and the memory life becomes shorter.
･ Fit the transfer rate of GCS-300 and PC-900.
･ It is not necessary to set instrument number to the GCS-300.
2. Connection
RS-485 [option code: C5]z When the converter is IF-100-C5, and between the converter and host computer
is connected by RS-232C.
Connection: RS-232C
RS-485 (Data transfer rate: 1200, 2400, 4800 or 9600bps)
When communicating by the transfer rate 19200bps, use IF-300-C5 instead of
IF-100-C5 for the converter.
Terminator (120Ω) built-in(Host computer)(IF-100-C5)

Shielding wire

(GCS-300)

TXD

2

YA ⑥

⑬

YA

RXD

3

YB ⑦

⑭

YB

SG

7

COM⑧

⑮

COM

⑬

YA

⑭

YB

⑮

COM

Shielding
wire

FG

1

RTS

4

⑭ RX

CTS

5

⑮ TX

DSR

6

⑯COM

DTR

20

CD

8

Shieldingwire
RS-485

RS-232C

Terminator (120Ω)D sub-connector 25-pin[Fig. 2-1]

z In case the converter is IF-100-C5, and between the converter and host computer
is connected by RS-422A.
Connection: RS-422A
RS-485 (Data transfer rate: 1200, 2400, 4800 or 9600bps)
Terminator (120Ω) built-in(Host computer)(IF-100-C5) Shielding wire

(GCS-300)

TXA

2

YA ⑥

⑬

YA

TXB

15

YB ⑦

⑭

YB

RXA

4

COM⑧

⑮

COM

RXB

17

COM

3

⑬

YA

⑭

YB

⑮

COM

FG

1

⑨ RXY
Shielding
wire

⑩ RXZ
⑪ TXY

Shielding
wire

⑫ TXZ
⑬ COM
RS-422A

RS-485

Terminator (120Ω)D sub-connector 25-pin[Fig. 2-2]

z Setting value digital transmission (Option code: SVTC)
When the option C5 (RS-485) is applied, connect the wire between the PC-900
and the GCS-300 as shown below.

(PC-900,C5)(GCS-300)

YA

⑪

⑬

YA

YB

⑫

⑭

YB

COM

⑯

⑮

COM

GND

①

⑬

YA

⑭

YB

⑮

COM

Shieldingwire

Shieldingwire

Terminator (120Ω)[Fig. 2-3]z As for the shielding wire･ Connect the shielding wire only one side to FG or ground (GND) terminal so as
not to flow the current into the shielding wire.
If both sides of the wire are connected to the FG or ground terminal, the circuit
is made between the wire and ground, and the noise may easily occur by the current.
･ The FG or ground terminal must be grounded.
z As for the terminator (Terminal resistor)･ The more the communication line becomes long, the less the communication
performs because the transfer waveform becomes wrong owing to the echo.
To prevent this, connect the terminator.
･ The place to connect should be the physical terminal of the communication cable.
z Communication converter of [IF-100-C5] or [IF-300-C5] is provided on separatesale.
3. As for the instrument setting･ When communicating by connecting plural GCS-300s in serial communication[option C5], the instrument number should be set individually.
･ Select the data transfer rate for the GCS-300 to fit the host computer.
･ Refer to the instruction manual of GCS-300 for the instrument number setting
and data transfer rate selection.

4. Communication procedure
RS-485 [Option code: C5]
Communications between a host computer and the GCS-300 are started by sending
the command from the host computer, and terminated by receiving the response
from the GCS-300.
Host computer

GCS-300

Command

Data

Command

Acknowledgement

Command･ Response with data
When the host computer sends the reading
command, GCS-300 returns the corresponding
setting value or current status as the
response.
･ Acknowledgement
If the host computer sends the settingcommand, GCS-300 returns acknowledgement(ACK) as the response after the processing
is terminated.
･ Negative Acknowledgement
When the host computer sends the command
not existent or the value beyond setting
range, GCS-300 returns negative
acknowledgement (NAK) for the response.

Negative acknowledgement

Command･ No response
GCS-300 will not respond when framing
error or checksum error has been detected
while the command is being received.

No response[Fig. 4-1]
z Communication timing of RS-485 [Option code: C5]･ As to the GCS-300 side
When the GCS-300 starts transmission to RS-485 communication line, the GCS-300
is arranged so as to provide 1 character transmission period or more of idle
status (mark status) to make the synchronous sure on the receiving side.
The GCS-300 is arranged so as to cut the transmitter off from the communicationline within the period of 1 character transmission after sending the response.
･ As to the host computer side
Make the program so that the host computer can provide 1 character transmission
period or more of idle status (mark status) before sending the command to
make the synchronous sure on the receiving side when the host computer starts
the transmission to RS-485 communication line.
Make the program so that the host computer can cut the transmitter off from thecommunication line within the period of 1 character transmission after sending thecommand in preparation for reception of the response from the GCS-300.
To avoid the collision of transmission between the host computer and the GCS-300,
send the next command after checking that the host computer surely received
the response.

In case the host computer communicates with the GCS-300 through the line
converter (IF-100-C5, IF-300-C5, sold separately), it is not required
to manage the transmission timing described above because the converter
takes the timing interpreting the protocol automatically.

5. Command configuration
5.1 Command configuration
All commands are composed of ASCII codes.
The data (setting value) are converted to Hexadecimal number
and ASCII codes are used for the command.
Negative number is represented by 2's complement.
(1) Command

HeaderAddress

Sub
address

Commandtype

Data item

163

162

161

Deli-

Data

160

163

162

Checksum

161

miter

160

[Fig. 5.1-1]
Header: STX(02H fixed), Start of text.
Control code to represent the beginning of the command (text).

Address: Instrument number 0 to 95 (20H to 7FH)
Number by which the host computer discriminates the GCS-300.
The numbers are used by giving 20H of bias (20H to 3FH),
because 0 to 31 (00H to 1FH) are used for control code.
95 (7FH) is called as Global address, and is used when sending
the same command to all the GCS-300s connected.
However, the response is not returned.

Sub address: It is fixed as 20H.

Command type : Code to discriminate the reading command
20H, Reading command
50H, Setting commandor setting command.

Data item: It represents the data sort for the command.
It is made up by 4 digits of hexadecimal number.
(Refer to the command table.)

Data: The contents of the data differ by the setting command.
It is made up by 4 digits of hexadecimal number.
(Refer to the command table.)
Reading command has no data.

Checksum: 2-character of data to detect a communication error.

Delimiter: ETX (03H, fixed), End of text.
Control code to represent the ending of the command (text).

(2) Response to the command･ Response with data (Response to the reading command)

HeaderAddress

Sub
address

Commandtype

Data item

163

162

161

Deli-

Data

160

163

162

161

Checksum

miter

160

[Fig. 5.1-2]
Header: ACK(06H, fixed), [Acknowledgement].
Control code to represent the beginning of the response.

Address: It represents the instrument number 0 to 95 (20H to 7FH).
The same code as the received command is used for the response.

Sub address : It is fixed as 20H
Command type : Code to discriminate the reading or setting command.
20H, Reading command
50H, Setting command
The same code as the received command is used for the response.

Data item

: It represents the data sort for the command.
It is made up by 4 digits of hexadecimal number.
(Refer to the command table.)
The same code as the received command is used for the response.

Data: The contents of the data differ by the reading command.
It is made up by 4 digits of hexadecimal number.
(Refer to the command table.)

Checksum: 2-character of data to detect a communication error.

Delimiter: ETX (03H, fixed), End of text.
Control code to represent the ending of the response.

z Acknowledgement

HeaderAddress

Checksum

Delimiter[Fig. 5.1-3]
Header: ACK(06H fixed), [Acknowledgement]
Control code to represent the beginning of the response.

Address: It represents the instrument number 0 to 95 (20H to 7FH).
The same code as the received command is used for the response.

Checksum: 2-character of data to detect a communication error.

Delimiter: ETX (03H, fixed), End of text.
Control code to represent the ending of the response.

z Negative acknowledgement

HeaderAddress

Error code

Checksum

Delimiter[Fig. 5.1-4]
Header: NAK(15H fixed), [Negative acknowledgement]
Control code to represent the beginning of the response.

Address: It represents the instrument number 0 to 95 (20H to 7FH).
The same code as the received command is used for the response.

Error code

: It represents the type of error.
It is made up by 1 digit of hexadecimal number.
1 (31H) When it is the command not existent
2 (32H) Not used
3 (33H) When setting is out of the range
4 (34H) When the status is not settable [Auto-tuning].
5 (35H) During the setting mode by key operation.

Checksum: 2-character of data to detect a communication error.

Delimiter: ETX (03H, fixed), End of text.
Control code to represent the ending of the response.

5.2 Checksum calculation
Checksum is used to detect a receiving error of the command or data.
Make the program for the host computer side as well to calculate the checksumof the response data from the GCS-300 to check the communication error.
ASCII code (hexadecimal) corresponding to the character from the address(instrument number) to the character front of the checksum is converted tobinary notation, and the total value is made.
The lower 2-digit of the total value are converted to 2’s complements andfurther to hexadecimal, that is, ASCII code. This is the checksum.
Refer to the following example procedure.
z Checksum calculation example is shown as follows.
Main setting value: 600℃ (Fixed value control)
Instrument number : 0 (20H)
Calculation range of the checksum

STX

P

0

0

0

1

0

2

5

8

ETX

35H

38H

03H

Converted from sending command to ASCII code

02H

20H

20H

50H

30H

30H

30H

31H

30H

32H

Checksum[Hexadecimal] [Binary notation]

＋

20H
20H
50H
30H
30H
30H
31H
30H
32H
35H
38H

0010
0010
0101
0011
0011
0011
0011
0011
0011
0011
0011
10 0010

0000
0000
0000
0000
0000
0000
0001
0000
0010
0101
1000
0000

1's complements:
Make each bit of binary 0 and 1 reverse.
2's complements:
Add 1 to the 1's complements.

＋(2's complements)

1101 1111 (1's complements)
11110 0000(Converted to the hexadecimal)

45H 30H("E") ("0")(ASCII code)[Code to be transmitted]

02H

20H

20H

50H

30H

30H

30H

31H

30H

32H

35H

38H

45H

30H

03H : ASCII code

STX (Space)(Space)

P

0

0

0

1

0

2

5

8

E

0

ETX

: ASCII
character6. Contents of the command
6.1 Notices for setting and reading command･ Though lock mode is designated by Setting value lock, the setting by
setting command is effective.
･ Even if the option is not applied, it is possible to set by settingcommand, however, the setting is ineffective.
･ The life of memory is approximately 1 000 000 (one million) in numberof times of writing. If the number of times exceeds the limit, itcannot memorize the data.
･ When connecting plural GCS-300s, the same instrument numbers should not
be applied to the plural GCS-300s.
･ When sending the command by Global address [95 (7FH)], the same commandis sent to all GCS-300s connected. However, the response is not returned.
･ The instrument number and data transfer rate of GCS-300 cannot be set
by communication. Set them by front key operations of the GCS-300.
z

As to setting command･ The settable range is the same as key operation. Refer to the Command table
for the communication command.
･ All commands are composed of ASCII codes.
･ The data (setting value) is converted to hexadecimal number, and ASCII codeis used. Negative number is represented by 2's complement.
･ When the data (setting value) has a decimal point, make the value 10 times
as much value as the setting.

z

As to reading command･ All commands are composed of ASCII codes.
･ The data (setting value) is converted to hexadecimal number, and ASCII codeis used. Negative number is represented by 2's complement.
･ When the setting value has a decimal point, it returns the value by making
10 times as much value as the setting.

6.2 Command table･ Table below describes data item, data and command type.
When the setting value for the data has a decimal point, make the value 10 times
as much value as the setting and convert to hexadecimal.

0001H
0002H
0003H

0004H
0005H
0006H
0007H
0008H
0009H

Data item
Main setting 1
Main setting 2
PID auto-tuning
Performance/Cancellation,
or PD Auto-reset Performance(Auto-reset can be performed
only when temperature is
within the proportionalband, however, cancelledautomatically in 4 minutes
after start.)
Proportional band setting
Reserved (Do not use.)
Integral time setting
Derivative time setting
Proportional cycle
setting
Reserved (Do not use.)

Data
Setting value
Setting value
0000H: Cancellation
0001H: Performance

Command type
20H/50H
20H/50H
20H/50H

Setting value

20H/50H

Setting value
Setting value
Setting value

20H/50H
20H/50H
20H/50H

000BH
000CH
000FH
0010H
0011H
0012H

0013H
0014H
0015H
0016H
001BH
001CH
001DH
001EH
001FH
0020H
0021H
0022H
0023H

0024H

0025H
0026H
0029H
002AH
0037H
0040H
0041H

Data item
Temperature alarm 1 (A1)setting
Temperature alarm 2 (A2)setting
Heater burnout alarm setting
Loop break alarm action
time setting
Loop break alarm action
span setting
Setting value lock selection.
When lock mode 3 is selected,
set data are not saved in thememory. By the power supply
off, the setting value
returns to the former one.
Main setting value
high limit setting
Main setting value
low limit setting
Sensor correction setting
Reserved (Do not use.)
PV filter time constantsetting
Output high limit setting
Output low limit setting
Output ON/OFF hysteresis
setting
Reserved (Do not use.)
Reserved (Do not use.)
Reserved (Do not use.)
Reserved (Do not use.)
Temperature alarm 1 (A1)action selection.
If alarm action type ischanged, the setting value
becomes 0, and output status
is initialized.

Temperature alarm 2 (A2)
action selection
If alarm action type ischanged, the setting value
becomes 0, and output status
is initialized.
Temperature alarm 1 (A1)action hysteresis setting
Temperature alarm 2 (A2)
action hysteresis setting
Temperature alarm 1 (A1)action delayed timer setting
Temperature alarm 2 (A2)
action delayed timer setting
Control output OFF function
setting
Temperature alarm 1 (A1)energized/deenergizedTemperature alarm 2 (A2)energized/deenergized

Data
Setting value

Command type
20H/50H

Setting value

20H/50H

Setting value
Setting value

20H/50H
20H/50H

Setting value

20H/50H

0000H: Unlock
0001H: Lock 1
0002H: Lock 2
0003H: Lock 3

20H/50H

Setting value

20H/50H

Setting value

20H/50H

Setting value

20H/50H

Setting value

20H/50H

Setting value
Setting value
Setting value

20H/50H
20H/50H
20H/50H

0000H: No alarm
0001H: High limit
0002H: Low limit
0003H: High and low limits
0004H: Hi/Lo limit range
0005H: Process high alarm
0006H: Process low alarm
0007H: High limit w/standby
0008H: Low limit w/standby
0009H: Hi/Lo limits w/standby

20H/50H

Data are the same as the alarm 20H/50H
1 action selection.

Setting value

20H/50H

Setting value

20H/50H

Setting value

20H/50H

Setting value

20H/50H

0000H: PV or SV display
0001H: OFF display
0000H: Energized
0001H: Deenergized
0000H: Energized
0001H: Deenergized

20H/50H
20H/50H
20H/50H

0044H

0045H
0047H
0070H

Data item
Sensor type selection

Data
0000H: K℃
0001H: J℃
0002H: E℃
0003H: Pt100℃
0004H: JPt100℃
0005H: Pt100℃(with decimal point)
0006H: JPt100℃(with decimal point)
0007H: K
0008H: J
0009H: E
0010H: Pt100
0011H: JPt100
Output Direct/Reverse action 0000H: Reverse actionchange0001H: Direct action
Auto-tuning bias setting
Setting value
Clearing the key operation
0000H: Not processedchange flag
0001H: All clearing

Command type
20H/50H

20H/50H
20H/50H
50H

0080H

Current PV reading

Current PV (Process variable)

20H

0081H

Current MV reading

Current MV (Manipulating value)

20H

0082H

Reserved (Do not use.)

0083H

Current SV reading

Current SV (Setting value)

20H

0085H

Current output status reading.

0086H

0000 0000
0000 0000
15
0
to
2
2
0
2 digit: Main control output
0: OFF, 1: ON(Current output unfixed)
1
2 digit: Reserved, always 0
2
2 digit: Alarm 1 (A1) output
0: OFF, 1: ON
3
2 digit: Alarm 2 (A2) output
0: OFF, 1: ON
4
2 digit: Always 0
5
2 digit: Always 0
62 digit: Heater burnout alarm
output0: OFF, 1: ON
7
2 digit: Loop break alarm output
0: OFF, 1: ON
8
2 digit: Over scale
0: OFF, 1: ON
9
Items below are not
2 digit: Under scale
15
applicable to 2 digit.
0: OFF, 1: ON
10
14･ Instrument number setting 2 to 2 digit: Always 0
15･ Data transfer rate setting 2 digit: Changed or Not changed
by key operation.
･ PV/SV display changing
0: Not changed･ MV display mode
1: Changed
Setting memory number reading Selected value

20H

20H

● Data items below (00A0H to 00A3H) are to know the specification of the instrumenton the monitoring software.

00A0H
00A1H

00A2H

00A3H

Data item
Data
Command type
20H
Reading the software version Numerical valueof instrument
20H
Reading the specification 1 0000 0000
0000 0000
150
of instrument
to2
2
0
2 digit: Always 0
1
2 digit: Reserved, always 0
2
2 digit: Alarm 1 (A1) appliedor not0: Not applied
1: Applied3
2 digit: Alarm 2 (A2) appliedor not0: Not applied
1: Applied4
5
2 , 2 digit: Not used,
always 0
6
2 digit: Heater burnout alarm
applied or not
0: Not applied
1: applied7
2 digit: Loop break alarm
applied or not
0: Not applied
1: applied
815
2 to 2 digit: Always 0
20H
Reading the specification 2 0000 0000
0000 0000
150
of instrument
to
2
2
0
2
2 to 2 digit: Model name
0(000): XXD
1(001): XXR
2(010): XXM
3(011): XXS
4(100): XXL
3
4
2 to 2 digit: Output type0(00) : R/
1(01) : S/
2(10) : A/
5
15
2 to 2 digit: always 0
Reading the data itemchanged by key operation.

The data item code changed
by key operation is read.
If plural items are changed,
the lowest value of data item
code is read.
The data item code iscleared after being read.

Data item code
When none of items is changed:
0(0000H)

20H

7. Specifications
Communication system: Half-duplex
Data transfer rate : 9600bps (2400, 4800, 9600, 19200bps)
Selectable by key operation.
Synchronous system : Start-stop
Code form: ASCII
Error detection: Parity check, Checksum
Error correction: Command request repeat system
Data format: Start bit 1
Data bit
7
ParityEven parity
Stop bit1
Start bit

Data bit

ParityStop bit

8. When troubled
When troubled, make sure the following items after checking the power supplyof the host computer and the GCS-300.
z Phenomenon: If it is unable to communicate.
Check the following
The connection. (Refer to Fig. 2-1 to 2-3.)
The burnout or imperfect contact on the communication cable and the connector.
Data transfer rate of the GCS-300 and the host computer.
The data bit, parity and stop bit of the host computer whether theyaccord with those of the GCS-300.
The instrument number of the GCS-300 and the command.
The same instrument number whether used in plural GCS-300s.
When communicating by RS-485 (option:C5) without IF-100-C5 or IF-300-C5(communication converter), make sure that the program is proper for thetransmission timing.

z Phenomenon: Though it is able to communicate, 'NAK' is responded.
Check the following
The command code is surely existent or not.
Whether the setting command exceeds the setting range or not.
In case of the situation being unable to set (such as AT performing).
The operation mode whether being under the setting mode by the
key operation.

If happened unclear phenomenon other than above mentioned, make inquiries
about the matters at our agency or the shop where you purchased.

SHINKO TECHNOS CO.,LTD.
OVERSEAS DIVISION
Reg. Office : 2-5-1, Senbahigashi, Minoo, Osaka, JapanURL: http://www.shinko-technos.co.jp
Tel : 81-72-727-6100
E-mail: overseas@shinko-technos.co.jp
Fax: 81-72-727-7006