Emerson Micro Motion CNG050 Modbus Problem

Dear All,
I want to connect HMI with Emerson micro motion to display some parameters link mass flow rate, mass inventory , volume inventory etc.
Address for these registers given in manual are 20247/20248, 20263/20264, 20265/20266.
But when I enter these addresses in HMI, then it shows communication error/address error.
If I use address 1/2/3/4/5/...... then communication is fine but the values are not what I want to access.
can anyone help please.
Thanks
Shoaib
 
The register addressing for Micromotion appears to be consolidated into a single reference manual at this link:
https://i.postimg.cc/yYV1LdNh/Micromotion-register-list-mixes-Holding-and-Input-Registers.jpg

Unfortunately, the manual is arranged by the values' number format - Floating point, coil, ASCII.

The type of Modbus register (Coil, Discrete Input, Holding register or Input register) is not explicitly stated, but a cryptic mystery message is probably the key to decoding which type of register is used
Micromotion register list mixes Holding and Input Registers.JPG

Modbus Input registers are read-only variables (as spec'd in the Modbus Specification). Those variables designated as RO, Read Only, are therefore likely Modbus Input registers. Modbus Input register are addressed by Modbus Function Code 04, and are notated as (3)xxxx where the leading numeral three designates an Input register

Modbus Holding registers can be read/write variables (as spec'd in the Modbus Specification). Those variables designated at R/W, read/write, are therefore likely Modbus Holding Registers. Modbus Holding Registers are addressed by Modbus Function Code 03 and are notated as (4)xxxx where the leading numeral four designates a Holding Register. (leading numeral is not part of the Modbus message, it's just an indicator for humans as to where the data resides).

Here's a screen shot of a section of the table showing the mass flow rate value.
primary variables, RO is Read Only.JPG

That table is for 32 bit floating point values. The Mass Flow rate value resides at registers 0247 and 0248. The RO is read only, so Mass Flow rate is likely an input register value.

Note, sometimes Input register values are also mapped to Holding Register Values, but the manual is making inferences, not statements.

You notated the mass flow value as 20437-20438. That can't be right. The leading numeral 2 is a conventional notation indicating that the value is a discrete input, which mass flow is not. Assuming Micromotion's inference about read-only versus read/write is the method they use to assign values to Modbus registers, then the mass flow would be in an Input Register, at (3)0247-(3)0248.

How one defines a target Modbus register varies by Modbus master/client implementation. Some need a Function code and a zero based register address minus the leading numeral, some want a one-based register address with the leading numeral and determine the Function code from the leading numeral.

If your master/client needs requires a Function Code, use FC 04 for an input register. Leave off the leading numeral 3 if the FC is used, so the target register is 0247.

If I were doing this, I'd read the temperature at (3)0251-(3)0252 because it's a fairly easy-to-determine value so you can recognize whether the value makes sense.

There's two commonly used floating point formats (that differ in word/byte order) and if your master uses the wrong one, the value will not even be reasonable, like 7.24e-5.342 and you'll have to find how to use the other format.

When you read 0002, if you were reading (3)0002 an input register, that is mass flow in 16 bit integer format. It is not clear from the manual where the decimal place is assumed for an integer value. Temperature is at (3)0004, also in integer format.

When you read 0004, is the value the temperature or temperature * 10, which is pretty common (tenths of a degree)?
 
I have tried by accessing 0247/0248 for mass flow rate but when I use these addresses then HMI shows address error.

1594103772377.png

these are the readings on software.
when I access mass inventory and volume inventory then the HMI showing address error.
what should I do?
 
I have tried by accessing 0247/0248 for mass flow rate but when I use these addresses then HMI shows address error.

View attachment 360

these are the readings on software.
when I access mass inventory and volume inventory then the HMI showing address error.
what should I do?
Hello All,
ghulamshoaib,

Can you send a "larger picture size" of the screen shoot???

We do not see clearly what kind of error message that system is sending??

Or could you write down the "exact error message displayed"??

I am looking on Micromotion and PROLINK2 manuals and it talks about CONFIGURING MODBUS .

I suggest you to check these manuals description for a correct configuration of your installation.

I can share ( by email as files size is too big for get attached here ) you these manuals if you dont got them yet.

Hope that it helps,
ControlsGuy25.
 
I have no idea what the image that you posted means.

What are those numbers and where do they come from?
What did you expect the numbers to be and how do the numbers vary from what you expected?
 
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