Porovnávané verzie

Kľúč

  • Tento riadok sa pridal
  • Riadok je odstránený.
  • Formátovanie sa zmenilo.

Fisher-Rosemount RS3 SCI communication protocol

Supported device types and versions
Communication line configuration
Communication station configuration
I/O tag configuration
Literature
Changes and modifications
Document revisions

Kotva
typy_verzie
typy_verzie
Supported device types and versions

...

The protocol supports the data transmission from/to the SCI (Supervisory Computer Interface) interface of the Fisher-Rosemount RS3 control system.

...

For a the correct communication of a Rosemount RS3 SCI device, these SCI parameters must be set:

Table 1

ParameterValue
Comm Port Baud Rate9.2 kbs or 38.4 kbs
ChecksumYes
Data Bits and Parity8N
XON/XOFF ControlOff
EIA OptionNone
Reply Header String in Hex format00 00 00 00
Reply Trailer String in Hex format00 00 00 00
ModeAsync Length LSB
Data FormatIEEE
TX Gap100 ms

Kotva
komunikacna_stanica
komunikacna_stanica
Communication station configuration

...

  • Communication protocol: Fisher-Rosemount RS3 SCI communication protocol.
  • Address parameters require to define specify the parameters First index and Update IntervalInterval parameters.
    • First index: A value within the interval 0..1499, address of the first I/O tag in the SCI table (Table Entry Location Number).
    • Update interval: Time period for the acquisition of new I/O tag values. Possible settings: cont. (continuallycontinuously), 5 sec., 10 sec., 15 sec., 30 sec., 1 min., 2 min., 5 min., 15 min. a and 60 min.

SCI allows to configure configuring acquisition of 1500 system values into its table (Table entry) with different parameters (Scaling, Update interval). Table entry entries are allocated to individual I/O tags from starting with the First index value First index. The station represents a logic logical set of tags with the same Update Interval parameter. Update Interval is a time period , using of with which the SCI acquires new values from the Rosemount S3 system.

Note: As the SCI configuration allows to define the parameter Update Interval up to 300 seconds (5 min.), the settings this setting is used for station polling periods of 15 and 60 minutes.


Station protocol parameters

There can be defined the The following station protocol parameters can be defined:

Table 2

KeywordFull nameMeaningUnitDefault value
Kotva
rc
rc
RC
Retry Count
Poll
Request repetition count in case of a communication error.-2
Kotva
rt
rt
RT
Retry Timeout
Delay between poll repetition
The delay between request repetitions in case of a communication error.ms200
Kotva
wft
wft
WFT
Wait First Timeout
Delay
The delay after transmitting the
poll
request and before reading the response.ms60
Kotva
wt
wt
WT
Wait TimeoutDelay between response readings
till
until its finalization.ms200
Kotva
mwr
mwr
MWR
Max Wait RetryRepetition count of response readings
till
until its finalization.-15
Kotva
dbg
dbg
DEBUG
Debug ModeIf the value of the parameter is YES, the tables on the side of the SCI device are not configured during communication (deletion from tables + initialization of individual points).
Parameter

The parameter is
used
used only for
debug
debugging purposes.YES/NONO
Kotva
sw
sw
SW
Send WeakIf the value is YES - if
there is acquired
a new I/O tag value with an error attribute is acquired, the error number will be sent to the I/O tag value and the value is marked by the WEAK attribute. It is used for debugging purposes only.YES/NONO

String A string containing the protocol parameters is being defined as follows:

...

Example:

SW=YES;WFT=300;

If there is used a keyword with an invalid value in the initialization string , there will be used is used, the corresponding default value according to the table 2 will be used.

Kotva
merany_bod
merany_bod
I/O tag configuration

...

Possible I/O tag types: Ai, Ao, Di, Dout

Communication supports value acquisition of I/O tags of the following types:

  • Analog values - I/O tag type AI, AO, used display scaling type “1”
  • Discrete (binary) values - I/O tag type DI, DO, used internal scaling type “0”.

Further, it allows to write new values of I/O tags of the following types:

  • Analog values - I/O tag type AO, used display scaling type “1”
  • Discrete (binary) values - I/O tag type DO, used internal scaling type “0”.

Note:


  • Display scaling - acquired values are equal with the RS3 system displaying
  • Internal scaling - discrete values are represented by : 0.0 - log. logical 0; 1.0 - log. logical 1


I/O tag address parameters

  • Block Variable - is the name of the Rosemount System 3 block variable. It is being defined in form of specified in string format, e.g. "=1E-75" (without quotes) for I/O tag tags of AI type and e.g. "=1F-25/b" for I/O tags of DI type.

Kotva
literatura
literatura
Literature

...

Kotva
revizie
revizie
Document revisions

...

  • Ver. 1.0 – March 5th, 2001
Info
titleRelated pages:

Communication protocols

...