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-Specication"
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 specication).
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 dene where the respective
measured values can be picked up in the temporary memory. The
conguration 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 specication, 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.
Temporary memory of VEGAMET/PLICSRADIO
(1 word = 2 byte)
3
1 Function as Modbus-TCP server
Register address in
Modicon
30004PC/DCS output 2: Status
30005PC/DCS output 3: Measured value
30006PC/DCS output 3: Status
30007PC/DCS output 4: Measured value
30008PC/DCS output 4: Status
30009PC/DCS output 5: Measured value
30010PC/DCS output 5: Status
30011PC/DCS output 6: Measured value
30012PC/DCS output 6: Status
Register address in
Modicon
30001PC/DCS output 1: Measured value
30002PC/DCS output 1: Status
30003PC/DCS output 2: Measured value
30004PC/DCS output 2: Status
30005PC/DCS output 3: Measured value
30006PC/DCS output 3: Status
30007PC/DCS output 4: Measured value
30008PC/DCS output 4: Status
30009PC/DCS output 5: Measured value
30010PC/DCS output 5: Status
30011PC/DCS output 6: Measured value
30012PC/DCS output 6: Status
……
30057PC/DCS output 29: Measured value
30058PC/DCS output 29: Status
30059PC/DCS output 30: Measured value
30060PC/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.
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.
StatusMeasured
value
0x000xXXXXValid measured value
0xXX0x8000An error number is transmitted in the status
0xXX0x00XXAn 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.
The following chart shows the addressing of the temporary memory
via Modbus.
5
1 Function as Modbus-TCP server
Register address in
Modicon
10001Fail safe relayFail safe LED
10002Relay 1Relay 1
10003Relay 2Relay 2
10004Relay 3Relay 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!
Register address in
Modicon
31001PC/DCS output 1: Measured value
31003PC/DCS output 1: Status
31005PC/DCS output 2: Measured value
31007PC/DCS output 2: Status
31009PC/DCS output 3: Measured value
31011PC/DCS output 3: Status
31013PC/DCS output 4: Measured value
31015PC/DCS output 4: Status
31017PC/DCS output 5: Measured value
31019PC/DCS output 5: Status
31021PC/DCS output 6: Measured value
31023PC/DCS output 6: Status
Temporary memory of VEGAMET/PLICSRADIO
(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…0Float Bit 31…16
Register addr. 31001Register addr. 31002
High-Byte/Low-ByteHigh-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 signicand). Second
register contains bits 31 … 16 of 32 bit number (exponent and bits
23 … 16 of signicand).
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.
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 dierent 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
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.
The following ASCII signs are interpreted as commands:
CommandDescription
VersionEnquiry of the protocol version
helpIndication of the command formats
clearstoreSettings 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.
30768-EN-130701
2 ASCII protocol
Options
The above commands of the measured value enquiry can be also
combined with the following options:
OptionDescription
TIMEThe current date/time is added to the answer
REPEAT xThe measured value is sent automatically by the signal condi-
STOREThe enquiry is saved up to the STORE option and executed
SUMA check sum is transmitted for each line which is sent
Information:
For commands and options no dierence is made between small
and capital letters. Each character string is terminated with Carriage
Return CR = CHR (13). The individual commands and options are
described below more in detail.
tioning instrument every x seconds
after a restart (only available with RS232 interface)
2.3 Version enquiry with command VERSION
With the command VERSION, the current protocol version can be
determined.
Example
Enquiry: version
•
Answer: VEGA ASCII Version 1.00
•
2.4 Help with command HELP
With the command HELP, a short information can be retrieved.
2.5 Delete the settings with the command
CLEARSTORE
With the command CLEARSTORE, the settings of the option STORE
are deleted in the EEPROM and the automatic repetition of the measured values is stopped.
2.6 Measured value enquiry with command %
% individual enquiry
As answer on the individual enquiry, the PC/DCS value stated in the
enquiry is delivered. The measured value is transmitted with three positions in front of the decimal point and one position after the decimal
point without unit.
Enquiry of the control
system
Identier1%
Begin1 … 3001 … 030 or 1 … 30
End identication1CR
Identier: "%" (1 character)
•
Start: No. of the requested PC/DCS output (1 … 3 characters)
DCS no.: No. of the PC/DCS output as 3-digit decimal number
•
T2: "#" (1 character)
•
Value: Numerical value of the PC/DCS output or with interferred
•
measured value the text "FAU LT"
Formatting of the value:
CharacterMeaning
1"- ": Minus with negative numbers
" ": Space with positive numbers
2 … 43-digit number
5".": Decimal point
61-digit number (after the decimal point)
T3: "%" (1 character)
•
End identication: Carriage Return CR (1 sign)
•
Total length of the telegram: 12 … 13 characters
Note:
The % sign is a separator, not the unit %
Enquiry:
%001
Answer:
=001# 067.3%
% Block enquiry
As answer on the block enquiry, all PC/DCS values assigned in the
instrument are delivered. The measured value is transmitted with
three positions in front of the decimal point and one position after the
decimal point without unit.
As answer to the range enquiry, the range stated in the enquiry with
PC/DCS values is delivered. The measured value is transmitted with
three decimal places in front of the decimal point and one decimal
place after the decimal point without unit.
As answer to the range enquiry, the range stated in the enquiry with
PC/DCS values is delivered. The measured value is transmitted with
three decimal places in front of the decimal point and one decimal
place after the decimal point without unit.
Number of bytesCharacter
Identier1%
Begin1 … 3001 … 030 or 1 … 30
Separator1-
End1 … 3001 … 030 or 1 … 30
End identication1CR
Identier: "%" (1 character)
•
Start: Start no. of the requested PC/DCS output (1 … 3 charac-
•
ters)
Separator: "-" (1 sign)
•
End: End no. of the requested PC/DCS output (1 … 3 characters)
(End-Start+1)-times repetition of the following telegram
Number of bytesCharacter
T11=
DCS no.3001 … 030
T21#
Value5 … 6-067.3
T31%
End identication1CR
T1: "=" (1 character)
•
DCS no.: No. of the PC/DCS output as 3-digit decimal number
•
T2: "#" (1 character)
•
Value: Numerical value of the PC/DCS output or with interferred
•
measured value the text "FAU LT"
Formatting of the value:
CharacterMeaning
1"- ": Minus with negative numbers
" ": Space with positive numbers
2 … 43-digit number
15
2 ASCII protocol
Example:
Enquiry of the control
system
Reply from the signal
conditioning instrument
CharacterMeaning
5".": Decimal point
61-digit number (after the decimal point)
T3: "%" (1 character)
•
End identication: Carriage Return CR (1 sign)
•
Total length of the telegram: (End-Start+1)*12 … 13
Note:
The % sign is a separator, not the unit %
Enquiry:
%002-004
Answer:
=002# 067.3%
=003# 824.6%
=004#-067.3%
2.7 Measured value enquiry with command &
& Single enquiry
As answer to the individual enquiry, the PC/DCS value stated in the
enquiry is deThe PC/DCS value stated in the enquiry is delivered as
reply to the individual enquiry. The measured value is transmitted with
six decimal places without decimal point and unit.
Number of bytesCharacter
Identier1&
Begin1 … 3001 … 030 or 1 … 30
End identication1CR
Identier: "&" (1 character)
•
Start: No. of the requested PC/DCS output (1 … 3 characters)
•
End identication: Carriage Return CR (1 sign)
•
Total length of the telegram: 3 … 5 characters
Number of bytesCharacter
T11=
DCS no.3001 … 030
T21#
Value7-000673
T31%
End identication1CR
T1: "=" (1 character)
•
DCS no.: No. of the PC/DCS output as 3-digit decimal number
Value: Numerical value of the PC/DCS output or with interferred
•
measured value the text "FAU LT"
Formatting of the value:
CharacterMeaning
1"- ": Minus with negative numbers
" ": Space with positive numbers
2 … 76-digit number after the decimal point
T3: "%" (1 character)
•
End identication: Carriage Return CR (1 sign)
•
Total length of the telegram: 14 characters
Note:
The % sign is a separator, not the unit %
Example:
Enquiry:
&001
Answer:
=001#-000673%
& Block enquiry
All assigned PC/DCS values in the instrument are delivered as reply
to the block enquiry. The measured value is transmitted with six decimal places without decimal point and unit.
The range stated in the enquiry with PC/DCS values is delivered as
reply to the range enquiry. The measured value is transmitted with six
decimal places without decimal point and unit.
Number of bytesCharacter
Identier1&
Begin1 … 3001 … 030 or 1 … 30
Separator1L or I
Quantity1 … 3001 … 030 or 1 … 30
End identication1CR
Identier: "&" (1 character)
•
Start: No. of the requested PC/DCS output (1 … 3 characters)
•
Separator: "L" or "I" (1 sign)
•
Quantity: Number of requested PC/DCS outputs (1 … 3 signs)
DCS no.: No. of the PC/DCS output as 3-digit decimal number
•
T2: "#" (1 character)
•
Value: Numerical value of the PC/DCS output or with interferred
•
measured value the text "FAU LT"
Formatting of the value:
CharacterMeaning
1"- ": Minus with negative numbers
" ": Space with positive numbers
2 … 76-digit number after the decimal point
T3: "%" (1 character)
•
End identication: Carriage Return CR (1 sign)
•
Total length of the telegram: Quantity*14 signs
Note:
The % sign is a separator, not the unit %
Enquiry:
&001L003
Answer:
=001#-000673%
=002# 008246%
=003#-000673%
& Block enquiry with range
The range stated in the enquiry with PC/DCS values is delivered as
reply to the range enquiry. The measured value is transmitted with six
decimal places without decimal point and unit.
Enquiry of the control
system
Identier1&
Begin1 … 3001 … 030 or 1 … 30
Separator1-
End1 … 3001 … 030 or 1 … 30
End identication1CR
Identier: "&" (1 character)
•
Start: Start no. of the requested PC/DCS output (1 … 3 charac-
•
ters)
Separator: "-" (1 sign)
•
End: End no. of the requested PC/DCS output (1 … 3 characters)
(End-Start+1)-times repetition of the following telegram
Number of bytesCharacter
T11=
DCS no.3001 … 030
T21#
Value5 … 6-000673
T31%
End identication1CR
T1: "=" (1 character)
•
DCS no.: No. of the PC/DCS output as 3-digit decimal number
•
T2: "#" (1 character)
•
Value: Numerical value of the PC/DCS output or with interferred
•
measured value the text "FAU LT"
Formatting of the value:
CharacterMeaning
1"- ": Minus with negative numbers
" ": Space with positive numbers
2 … 76-digit number after the decimal point
T3: "%" (1 character)
•
End identication: Carriage Return CR (1 sign)
•
Total length of the telegram: (End-Start+1)*14
Note:
The % sign is a separator, not the unit %
Enquiry:
&001-003
Answer:
=001# 000673%
=002# 008246%
=003#-000673%
2.8 Measured value enquiry with command?
? individual enquiry
The PC/DCS value stated in the enquiry is delivered as reply to the
individual enquiry. The measured value is transmitted with six decimal
places without decimal point and with unit.
Start: No. of the requested PC/DCS output (1 … 3 characters)
•
End identication: Carriage Return CR (1 sign)
•
Total length of the telegram: 3 … 5 characters
Number of bytesCharacter
T11=
DCS no.3001 … 030
T21#
Value7-000673
T31#
Unit0 … nxxx
End identication1CR
T1: "=" (1 character)
•
DCS no.: No. of the PC/DCS output as 3-digit decimal number
•
T2: "#" (1 character)
•
Value: Numerical value of the PC/DCS output or with interferred
•
measured value the text "FAU LT"
Formatting of the value:
CharacterMeaning
1"- ": Minus with negative numbers
" ": Space with positive numbers
2 … 76-digit number after the decimal point
T3: "#" (1 character)
•
Unit: Unit as text (0 … n unit)
•
End identication: Carriage Return CR (1 sign)
•
Total length of the telegram: 14 characters+Unit character
Enquiry:
?001
Answer:
=001# 000673#%
? Block enquiry
All assigned PC/DCS values in the instrument are delivered as reply
to the block enquiry. The measured value is transmitted with six decimal places without decimal point and with unit.
The range stated in the enquiry with PC/DCS values is delivered as
reply to the range enquiry. The measured value is transmitted with six
decimal places without decimal point and with unit.
Start: No. of the requested PC/DCS output (1 … 3 characters)
•
Separator: "L" or "I" (1 sign)
•
Quantity: Number of requested PC/DCS outputs (1 … 3 signs)
•
End identication: Carriage Return CR (1 sign)
•
Total length of the telegram: 5 … 9 characters
Reply from the signal
conditioning instrument
Example:
"N"-times repetition of the following telegram
Number of bytesCharacter
T11=
DCS no.3001 … 030
T21#
Value7-000673
T31#
Unit0 … nxxx
End identication1CR
T1: "=" (1 character)
•
DCS no.: No. of the PC/DCS output as 3-digit decimal number
•
T2: "#" (1 character)
•
Value: Numerical value of the PC/DCS output or with interferred
•
measured value the text "FAU LT"
Formatting of the value:
CharacterMeaning
1"- ": Minus with negative numbers
" ": Space with positive numbers
2 … 76-digit number after the decimal point
T3: "#" (1 character)
•
Unit: Unit as text (0 … n unit)
•
End identication: Carriage Return CR (1 sign)
•
Total length of the telegram: Number*(14 characters+Unit character)
Enquiry:
?001L003
Answer:
=001# 000673#%
=002# 008246#kg
=003#-000673#m
? Block enquiry with range
The range stated in the enquiry with PC/DCS values is delivered as
reply to the range enquiry. The measured value is transmitted with six
decimal places without decimal point and with unit.
(End-Start+1)-times repetition of the following telegram
Number of bytesCharacter
T11=
DCS no.3001 … 030
T21#
Value11-824.6
T31#
Unit0 … nxxx
End identication1CR
T1: "=" (1 character)
•
DCS no.: No. of the PC/DCS output as 3-digit decimal number
•
T2: "#" (1 character)
•
Value: Numerical value of the PC/DCS output or with interferred
•
measured value the error code "Exxx"
30768-EN-130701
Example:
Example
2 ASCII protocol
Formatting of the value:
CharacterMeaning
1"- ": Minus with negative numbers
" ": Space with positive numbers
2 … 1111-digit number with comma or error code
T3: "#" (1 character)
•
Unit: Unit as text (0 … n unit)
•
End identication: Carriage Return CR (1 sign)
•
Total length of the telegram: (End-Start+1)*(18 characters+Unit
character)
Enquiry:
$001-003
Answer:
=001# 67.3 #kg
=002# 824.3 #%
=003#-67.3 #m
2.10 Option TIME
By adding the attribute TIME, the current time will be transmitted
before the reply. The transmission of date/time information is carried
out in the format "@YYYY/MM/DD hh:mm:ss". The character string
contains 21 characters incl. CR.
YYYY - year with 4 decimal places
•
MM - month with 2 decimal places
•
DD - day with 2 decimal places
•
hh - hours in 24 h format with 2 decimal places
•
mm - minutes with 2 decimal places
•
ss - seconds with 2 decimal places
•
Note:
The character string is terminated with CR.
Enquiry:
$001 time
Answer:
@2005/04/07 09:00:50
=001# 24.44 #%
2.11 Option REPEAT x
By attaching the attribute REPEAT and a number x, the transmitted
enquiry will be repeated every x seconds. If the value for the repetition
is = 0, a measured value is only retrieved once. A repetition rate less
than 5 seconds is not possible.
By adding the attribute STORE, the enquiry is stored in the EEPROM
memory up to the option STORE. After switching on the instrument
again, this enquiry will be used as input telegram and an answer will
be generated.
Note:
This option is only available for the RS232 interface.
Voltage interruption: If the instrument is now switched o and then
switched on again, the instrument automatically sends the reply to the
saved enquiry telegram.
@2005/04/07 09:03:19
=001# 27.55 %
=002# 28.44%
…
2.13 Option SUM
By attaching the attribute SUM, a check sum is built for each line of
the reply. The check sum is the sum of all binary characters up to the
start of the sum itself in modulo 65535.
All statements concerning scope of delivery, application, practical use and operating conditions of the sensors and processing systems correspond to the information
available at the time of printing.
Subject to change without prior notice