Fisher-Rosemount RS3 RNI communication protocol
Supported device types and versions
The protocol implementation supports reading and writing data into the Fisher-Rosemount RS3 system by means of RNI Ethernet network driver (Remote Network Interface) -a TCP/IP network communication is used.
Communication uses the following methods for data acquisition from RNI:
- DDS: Dynamic Data Server – acquisition of process tag values on-change.
- RW Services: Read/Write Services – used for writing values 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,
- For 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 finding RNI IP address (in the Windows NT OS, 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 userfile.cfg file – 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 writing to RS3 is required, the user access rights must be CONFIGURE.
I/O tag configuration
Possible types: Ai, Ao, Ci, Co, Di, Do, TiA
The address is the name or address of the 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 - output (Q) of tag =1H-01
AI-701.B - B input of AI-701 tag
=7A-02.@ - all @ flags of tag =7A-02 as a 16-bit unsigned integer
For digital tags, the I/O address can be defined in the following forms:
Or if COMMAND is @:
- The RS3 tag name is each valid tag name.
- RS3 address is in =NXXNNN form for I/O blocks and in =NX-NN form 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 a 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 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) to assign the I/O tag to one of the Update Rate groups. The Update Rate groups are used by the DDS service and they define a period of reading data from the RS3. The Update Rate groups are configured on the booting computer in the dds.cfg file.
Changes and modifications
- Ver. 1.1 – February 9th, 2000 – Document update.