Fisher-Rosemount RS3 RNI communication protocol
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:
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 :
Or if COMMAND is @:
- RS3 tag name is each valid tag name.
- 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.
- 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‘.
|Item name||D2000 type||I/O||Comment|
|T or T.Q||AI, AO||I/O||Output Value|
|T.VS||CI||I||System Flags – all|
|T.MD||CI, CO||I/O||Block Mode|
|T.A up to T.O||AI, AO||I/O||Input Values|
|T.U||CI, CO||I/O||User Flags – all|
|T.U\a up to T.U\p or
T.Ua up to T.Up or
T.a up to T.p
|DI, DO||I/O||User Flag – individually|
|T.@||CI||I/O||Discrete Inputs – all|
|T.@a up to T.@p||DI||I/O||Discrete Input – individually|
|T.TS||CI||I||T System Flags|
|T.SA up to T.SO||CI||I||System Flags A – O|
|T.UA up to T.UO||CI||I||User Flags A – O|
|T.ATP||AI||I||Auto Tune Phase|
|T.AGF||AI||I||Actual Gain Factor|
|T.CGF||AI||I||Calculated Gain Factor|
|T.AIT||AI||I||Actual Integral Time|
|T.CIT||AI||I||Calculated Integral Time|
|T.ADT||AI||I||Actual Derivate Time|
|T.CDT||AI||I||Calculated Derivate Time|
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.
Changes and modifications
- Ver. 1.1 – February 9th 2000 – Document update.