TotalFlow G4/G5 Modbus Slave Registers

[Nmill]

Hello all,


I am working on project to pull data from G4/G5 ABB Totalflows via a modbus master/data radio. I don't have a physical totalflow with me to test on until I'm back in the field so I thought an expert might be able to help with my question and clarify a detail for me. I am currently just using the G4 sim in PCCU32 from ABB.



The totalflow Comm 1 will be set to 16 bit RTU slave connected via RS485 to the Modbus master/data radio. In the modbus register map I want to read 13 or so float values mapped to a register:


Example 7001 = 11.7.19 (Volume Flow Rate)

Since I need to use 16 bit and the float being 32 bit it will take up 2 consecutive registers to do this. I can't see if the totalflow will block out the next register or not, example 7001/7002 for 11.7.19. Then 7003/7004 for 11.7.22 (Todays Volume) etc..



How should I create the register map? Individual files for each one? Anyone have experience with this?



Screenshot of how I think it may work attached. It won't let me add 0.0.0 to block out a register either..



Thank you experts

 

[danw]

Have you read the instructions like those in the Modbus Configuration Guide X Series G4 at this link:
https://search.abb.com/library/Down...eCode=en&DocumentPartId=2106280&Action=Launch

On pages 15-17 there are screen shots showing the use of the 1.2.3 formatted internal registers (A.A.R. locations?). I'm too lazy to read the whole thing to figure what the 1.2.3 are internally, but they're there.

If this isn't the exact manual for your device, then there will probably be one; ABB seems to have a very comprehensive library on-line.

 

[Nmill]

That manual is actually very handy. Thank you! I thought I had read them all but must have missed that one.. I had reached out to ABB weeks ago but have had no response.

The problem is that guide all focuses on 32bit format (RTU and ASCII) which still leaves my question about the 16bit registers in RTU format. My gut feeling is that mapping say register 7001 to 11.7.19 will take up 7001+7002 but for some reason I can't see in PCCU32 if it blocks out both 7001/7002 for that 11.7.19 float value (32bit).


In my testing with a slave sim (Simply modbus), it behaves how i would expect. screenshot attached below.



If someone had a G4 or G5 they could test on that would be incredibly helpful.

 

[Blue01]

Don't think 16 bit works for the Totalflows. I have never had any luck with it. Have you considered just using the Ethernet port? Beats modbus.

 

[Nmill]

Care to elaborate? It doesn’t work at all? For this project I need to use modbus to a data radio.. No Ethernet option for this one.

 

[danw]

The example on page 15 uses the "register format of 32 bit Totalflow" where Totalflow is designated TF in other places in the manual. I assume the register format is that V1.2.3 designation.

However, the screen shot of page 15 has the Register type selected as "Float". I suspect that the drop-down menu allows for the selection of signed or unsigned integer if the communications parameter "register format" is configured for 16 bit Modicon, not 32 bit or 32 bit TF.

The table on page 40 shows the default communication parameters, one of which is "Reg Format" of various flowmeter models, most of which default to 32 bit, some 32 bit TF. On page 41, the Reg Format communications parameter that can be selected as 16 bit Modicon, which is presumably the standard Modbus format that you're looking for.