Fisher-Rosemount RS3 RNI communication protocol

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

Supported device types and versions

The protocol allows reading and writing data into Fisher-Rosemount RS3 system by means of RNI Ethernet network driver (Remote Network Interface) -there is used TCP/IP network communication.

Communication uses the following methods for data acquisition from RNI:

• DDS: Dynamic Data Server – acquisition of process tag values when they change.
• RW Services: Read/Write Services – used for value writing into RS3.

The methods are described in the Fisher-Rosemount Systems RNI Programmer’s Manual documentation, Software Version 2.3, April 1997.

Communication line configuration

• communication line category: API,
• The other parameters - see the D2000 System configuration.

Communication station configuration

• communication protocol: Fisher-Rosemount RNI.
• Station address consists of the following parameters :

RNI Name – RNI name allows to find RNI IP address (in the OS Win NT, the name together with the IP address is stored in the file %SystemRoot%\system32\drivers\etc\hosts)

Name – user access name (it is configured together with access rights on the boot PC for RNI in the file userfile.cfg – see the RNI configuration manual)

Password – password to given access menu

You must pay attention when you select the user's access right (D2000 KOM)  - if there is required writing to RS3, the user access rights must be CONFIGURE.

I/O tag configuration

Possible types: Ai, Ao, Ci, Co, Di, Do, TiA

Address is the name of of I/O RS3 tag. For analog I/O tags, the address can be defined in the following forms:

SYSTEM_3_TAG_NAME

SYSTEM_3_ADDRESS

SYSTEM_3_TAG_NAME.COMMAND

SYSTEM_3_ADDRESS.COMMAND

For example:

AI-701 - AI-701 tag output (Q)

=1H-01 - tag output (Q) =1H-01

AI-701.B - B input of AI-701 tag

=7A-02.@ - all @ tag flags =7A-02 as 16-bit unsigned integer

For digital tags, the I/O address can be defined in the following forms :

SYSTEM_3_TAG_NAME.COMMAND\FLAG

SYSTEM_3_ADDRESS.COMMAND\FLAG

Or if COMMAND is @:

SYSTEM_3_TAG_NAME.@FLAG

SYSTEM_3_ADDRESS.@FLAG

For example:

AI-702.U\d

=1H-1.U\c

AI-702.@e

=1H-1.@a

1. RS3 tag name is each valid tag name.
2. RS3 address is in form of =NXXNNN for I/O blocks and =NX-NN for control blocks, where N is a number and X is a character.
3. System flags and User flags that are read as analog values are represented by 16-bit unsigned integer.

The following table contains valid ‘command’ names for RNIDDE. The first column contains the short name of RS3 I/O tag as the letter of T, the tag name is followed by the character (.) and a ‘command‘.

When you configure an I/O tag, you must select one of four radio buttons (UR1 to UR4) of the parameter Update rate. The update rate is used by the DDS service and defines a data read period from RS3. The update rate is configured on the boot computer in the file dds.cfg.

Literature

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Changes and modifications

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Document revisions

• Ver. 1.1 – February 9th 2000 – Document update.