VEGA Modbus-TCP User Manual

Supplementary instructions

Modbus-TCP, ASCII protocol

VEGAMET 391/624/625, VEGASCAN 693, PLICSRADIO C62

Internet

PLC/SPS

Document ID: 30768

Contents

1 Function as Modbus-TCP server

1.1 Modbus-TCP - general description ................................................................................... 3

1.2 Filing of the measured value as 2 byte short .................................................................... 3

1.3 Filing of measured value as 4 Byte Float .......................................................................... 6

2 ASCII protocol

2.1 Measured value enquiry via ASCII protocol ...................................................................... 9

2.2 Overview of the commands and options ........................................................................ 10

2.3 Version enquiry with command VERSION ...................................................................... 11

2.4 Help with command HELP ............................................................................................. 11

2.5 Delete the settings with the command CLEARSTORE ................................................... 11

2.6 Measured value enquiry with command % ..................................................................... 11

2.7 Measured value enquiry with command & ...................................................................... 16

2.8 Measured value enquiry with command? ....................................................................... 20

2.9 Measured value enquiry with command $ ...................................................................... 25

2.10 Option TIME ................................................................................................................... 29

2.11 Option REPEAT x ........................................................................................................... 29

2.12 Option STORE ............................................................................................................... 30

2.13 Option SUM ................................................................................................................... 30

Modbus-TCP, ASCII protocol • VEGAMET 391/624/625, VEGASCAN 693, PLICSRADIO C62

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1 Function as Modbus-TCP server

1.1 Modbus-TCP - general description

VEGAMET 391/624/625, VEGASCAN 693 and PLICSRADIO C62 signal conditioning instruments work as Modbus-TCP servers and make the existing PC/DCS values and relay switching conditions available in a temporary storage for collection via Modbus-TCP.

The instruments comply with the "Open Modbus-TCP-Specication" Release 1.0 from Schneider Electric. This standard is supported by many process control systems, remote IOs, visualisation programs and OPC servers. Communication is carried out via Port 502.

Beside the PC/DCS values, the switching conditions of the relay outputs can also be queried.

The enquiry of the PC/DCS values and relay values is made via the

appropriate function code (see also Modbus specication).

Function code 01: Read Coil Status (enquiry of the relay values)

•

Function code 02: Read Input Status (enquiry of the relay values)

•

Function code 03: Read Holding Registers (enquiry of the PC/

•

DCS values)

Function code 04: Read Input Registers (enquiry of the PC/DCS

•

values)

These function codes are normally available as library enquiries in the

PLC (e.g. Modicon).

PC/DCS output

VEGAMET 391/624/625 and PLICSRADIO C62 can provide up to six PC/DCS outputs, VEGASCAN 693 up to 30. Further relay values also exist (fail safe relay/operating relay, depending on the instrument

type).

Via the selected PC/DCS output you dene where the respective

measured values can be picked up in the temporary memory. The

conguration of the PC/DCS outputs is carried out via PACTware/

DTM.

1.2 Filing of the measured value as 2 byte short

The addressing of the PC/DCS values for Modbus systems is carried out "Word-orientated". In the temporary memory, a PC/DCS value is

represented by two words. The rst word contains the actual PC/DCS

value, the next higher word the corresponding status information. In

the specication, the term register word is also used instead of word.

The ling of measured values in the temporary memory is always

sorted according to PC/DCS output number. The following chart shows the addressing of the temporary memory via Modbus.

30001 PC/DCS output 1: Measured value

30002 PC/DCS output 1: Status

30003 PC/DCS output 2: Measured value

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Modbus-TCP, ASCII protocol • VEGAMET 391/624/625, VEGASCAN 693, PLICSRADIO C62

Temporary memory of VEGAMET/PLICSRADIO (1 word = 2 byte)

1 Function as Modbus-TCP server

30004 PC/DCS output 2: Status

30005 PC/DCS output 3: Measured value

30006 PC/DCS output 3: Status

30007 PC/DCS output 4: Measured value

30008 PC/DCS output 4: Status

30009 PC/DCS output 5: Measured value

30010 PC/DCS output 5: Status

30011 PC/DCS output 6: Measured value

30012 PC/DCS output 6: Status

30001 PC/DCS output 1: Measured value

30002 PC/DCS output 1: Status

30003 PC/DCS output 2: Measured value

30004 PC/DCS output 2: Status

30005 PC/DCS output 3: Measured value

30006 PC/DCS output 3: Status

30007 PC/DCS output 4: Measured value

30008 PC/DCS output 4: Status

30009 PC/DCS output 5: Measured value

30010 PC/DCS output 5: Status

30011 PC/DCS output 6: Measured value

30012 PC/DCS output 6: Status

… …

30057 PC/DCS output 29: Measured value

30058 PC/DCS output 29: Status

30059 PC/DCS output 30: Measured value

30060 PC/DCS output 30: Status

Temporary memory of VEGAMET/PLICSRADIO (1 word = 2 byte)

Temporary memory of VEGASCAN (1 word = 2 byte)

As an alternative, register address 40001 is also available as start

address (function code 03).

Format of the PC/DCS value

The actual measured values are transmitted as signed data comprising two octets. This means that the value range encompasses max. +32768 to -32767. In addition to the measured value, the status of the measured value is delivered in a second register word.

Modbus-TCP, ASCII protocol • VEGAMET 391/624/625, VEGASCAN 693, PLICSRADIO C62

30768-EN-130701

1 Function as Modbus-TCP server

Example of the data of a PC/DCS output

Measured value Status

High-Byte/Low-Byte High-Byte/Low-Byte

The status describes the condition of the associated measured value. The content of the measured value is only valid if the corresponding status has the value zero. If there is a status value unequal zero, the

status value and the corresponding value in the measured value eld

must be taken into account in a detailed failure diagnosis. The following chart explains the possible faults.

Status Measured

value

0x00 0xXXXX Valid measured value

0xXX 0x8000 An error number is transmitted in the status

0xXX 0x00XX An error number which corresponds to the er-

Note:

When transmitting the PC/DCS value in Modbus-TCP protocol

(measured value ling as 2 byte short), the decimal point itself is not

transmitted; the value -0.5 bar is transmitted as -50. If a data format was selected that allows values outside the value range to appear, a limit is set at the highest value of the value range.

Example: Percent was selected as "Reference value " and #.### as "Data format ". With this setting, the value 100 % would be transmitted as 100000, which is outside the valid range of max. +32767. This means that a limit will be imposed and 32767 transmitted instead. To avoid this, "Data format " #.## should be chosen so that the value 100 % is transmitted as 10000.

Note:

On the switching inputs of PLICSRADIO C62 (measurement loops 4 … 6) the values 0 (switch open) and 100 (switch closed) are transmitted as measured values; the units are discarded.

Meaning

corresponding to the error codes Exx (e.g. 29

= E29 = Simulation).

ror codes Exx is transmitted in the status and

in the measured value. Must be congured

via DTM.

Filing of the relay values

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Modbus-TCP, ASCII protocol • VEGAMET 391/624/625, VEGASCAN 693, PLICSRADIO C62

The switching conditions of the relay are transferred as bit information.

The following equivalencies apply to the switching relays:

0 = Switching status O

•

1 = Switching status On

•

The following equivalencies apply to the fail safe relay:

0 = Failure message O, relay switching condition On

•

1 = Failure message O, relay switching condition O

•

The following chart shows the addressing of the temporary memory via Modbus.

1 Function as Modbus-TCP server

10001 Fail safe relay Fail safe LED

10002 Relay 1 Relay 1

10003 Relay 2 Relay 2

10004 Relay 3 Relay 3

10005 ---- Relay 4

10006 ---- Relay 5

10007 ---- Relay 6

Temporary memory of VEGAMET/PLICSRADIO (1 bit)

Temporary memory of VEGAMET 391 (1 Bit)

1.3 Filing of measured value as 4 Byte Float

The ling of measured values in the temporary memory is always

sorted according to PC/DCS output number. The following chart shows the addressing of the temporary memory via Modbus. The values are accessed via FC 3 and 4. The status information is also transmitted as oat value. 8 byte are needed for one output, corresponding to 4 registers.

Information:

Note: A oat value comprises 2 registers, i.e. a total of 4 bytes!

31001 PC/DCS output 1: Measured value

31003 PC/DCS output 1: Status

31005 PC/DCS output 2: Measured value

31007 PC/DCS output 2: Status

31009 PC/DCS output 3: Measured value

31011 PC/DCS output 3: Status

31013 PC/DCS output 4: Measured value

31015 PC/DCS output 4: Status

31017 PC/DCS output 5: Measured value

31019 PC/DCS output 5: Status

31021 PC/DCS output 6: Measured value

31023 PC/DCS output 6: Status

Temporary memory of VEGAMET/PLICSRADIO (2 words = 4 byte)

31001 PC/DCS output 1: Measured value

31003 PC/DCS output 1: Status

31005 PC/DCS output 2: Measured value

31007 PC/DCS output 2: Status

31009 PC/DCS output 3: Measured value

Modbus-TCP, ASCII protocol • VEGAMET 391/624/625, VEGASCAN 693, PLICSRADIO C62

Temporary memory of VEGASCAN (2 words = 4 byte)

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1 Function as Modbus-TCP server

Format of the PC/DCS value

31011 PC/DCS output 3: Status

31013 PC/DCS output 4: Measured value

31015 PC/DCS output 4: Status

31017 PC/DCS output 5: Measured value

31019 PC/DCS output 5: Status

31021 PC/DCS output 6: Measured value

31023 PC/DCS output 6: Status

… …

31113 PC/DCS output 29: Measured value

31115 PC/DCS output 29: Status

31117 PC/DCS output 30: Measured value

31119 PC/DCS output 30: Status

Temporary memory of VEGASCAN (2 words = 4 byte)

As an alternative, register address 41001 is also available as start

address (function code 03).

The actual measured values are transmitted as signed data comprising four octets. In addition to the measured value, the status of the measured value is supplied in a second register word.

Example of the data of a PC/DCS output

Float Bit 15…0 Float Bit 31…16

High-Byte/Low-Byte High-Byte/Low-Byte

Note:

On the switching inputs of PLICSRADIO C62 (measurement loops 4 … 6) the values 0 (switch open) and 100 (switch closed) are transmitted as measured values; the units are discarded.

Floating point of OPEN MODBUS/TCP SPECIFICATION

984 Floating point: Intel single precision real. First register contains

bits 15 … 0 of 32 bit number (bits 15 … 0 of signicand). Second

23 … 16 of signicand).

status value and the corresponding value in the measured value eld

must be taken into account in a detailed failure diagnosis. The following chart explains the possible faults.

Status Measured

value

0 XXXX Valid measured value

Meaning

30768-EN-130701

Modbus-TCP, ASCII protocol • VEGAMET 391/624/625, VEGASCAN 693, PLICSRADIO C62

1 Function as Modbus-TCP server

Filing of the relay values

Status Measured

value

<> 0 0 An error number is transmitted in the status

<> 0 XX0XX An error number which corresponds to the er-

Meaning

corresponding to the error codes Exx (e.g. 29

= E29 = Simulation).

ror codes Exx is transmitted in the status and

in the measured value. Must be congured

via DTM.

The switching conditions of the relay are transferred as bit information.

The following equivalencies apply to the switching relays:

0 = Switching status O

•

1 = Switching status On

•

The following equivalencies apply to the fail safe relay:

0 = Failure message O, relay switching condition On

•

1 = Failure message O, relay switching condition O

•

The following chart shows the addressing of the temporary memory via Modbus.

10001 Fail safe relay Fail safe LED

10002 Relay 1 Relay 1

10003 Relay 2 Relay 2

10004 Relay 3 Relay 3

10005 ---- Relay 4

10006 ---- Relay 5

10007 ---- Relay 6

Temporary memory of VEGAMET/PLICSRADIO (1 bit)

Temporary memory of VEGAMET 391 (1 Bit)

As an alternative, register address 00001 is also available as start address.

Modbus-TCP, ASCII protocol • VEGAMET 391/624/625, VEGASCAN 693, PLICSRADIO C62

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2 ASCII protocol

2.1 Measured value enquiry via ASCII protocol

With the ASCII protocol you can enquire PC/DCS values via the Ethernet or RS232 interface. Through the use of ASCII characters, measured value enquiry is possible using simple terminal programs such as HyperTerminal.

The PC/DCS values are retrieved by special commands. It is possible

to get the measured value in dierent resolutions, with/without unit or

with current date/time.

Access via RS232

Access via Ethernet

The activation of the ASCII protocol is carried out via the instrument DTM under "Device settings - RS232 interface". For the ASCII protocol, the following interface parameters are default settings:

Coding system: 8 Bits, ASCII

•

Baud rate: 9600 Bits/sec

•

Data bits: 8

•

Parity: none

•

Stop bits: 1

•

For direct connection between signal conditioning instrument and PC or DCS, the RS232 modem connection cable and an additionally connected interlink cable from the scope of delivery will be required. If connection is provided via modem, only the attached RS232 modem

connection cable is used. You will nd further information in chapter

"Connection".

The ASCII protocol is handled via the TCP/IP - Port 503. When using the terminal program HyperTerminal, the following settings are required:

IP addr. of the signal conditioning instrument: 192.168.200.200

•

(default setting)

TCP/IP Port: 503

•

Connection: TCP/IP

•

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Modbus-TCP, ASCII protocol • VEGAMET 391/624/625, VEGASCAN 693, PLICSRADIO C62

2 ASCII protocol

Fig. 1: Connection via HyperTerminal

The setting of "telnet:\\192.168.200.200:503" in the address eld of the Internet Explorers starts the terminal program HyperTerminal automatically. Max. four simultaneous connections are possible.

2.2 Overview of the commands and options

Commands

Modbus-TCP, ASCII protocol • VEGAMET 391/624/625, VEGASCAN 693, PLICSRADIO C62

The following ASCII signs are interpreted as commands:

Command Description

Version Enquiry of the protocol version

help Indication of the command formats

clearstore Settings of the option Store will be deleted in the EEPROM

memory

% Measured value enquiry with three places in front of the deci-

mal point and one place after the decimal point without unit

& Measured value enquiry with six places after the decimal point

and without unit

? Measured value enquiry with six positions after the decimal

point and with unit

$ Measured value enquiry with 11 places as oating point and

with unit

Note:

On the switching inputs of PLICSRADIO C62 (measurement loops 4 … 6) the values 0 (switch open) and 100 (switch closed) are transmitted as measured values; the units are discarded.

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