Schneider M221 Modbus RTU

Jonnie_R

Member
Join Date
Feb 2012
Location
Brecon
Posts
216
Whilst I'm waiting for the PLC to turn up next week, I thought I'd see if anyone here can answer the question/confirm my thoughts.

I am connecting to the M221 using a Weintek screen, and in the data types available it doesn't list MF(memory float), only MW(memory word) or MD(memory double).

Has anyone read a 32 bit float from an M221 directly, or do you have to read individual words and then assemble them as 32 bit registers, or can it be read in as a MD?

It doesn't matter too much as I can convert the float to a double on the PLC to get an integer, and then divide it back again in a macro on my screen, just thinking of ways to make my life a little less complicated.
 
Whilst I'm waiting for the PLC to turn up next week, I thought I'd see if anyone here can answer the question/confirm my thoughts.

I am connecting to the M221 using a Weintek screen, and in the data types available it doesn't list MF(memory float), only MW(memory word) or MD(memory double).

Has anyone read a 32 bit float from an M221 directly, or do you have to read individual words and then assemble them as 32 bit registers, or can it be read in as a MD?

It doesn't matter too much as I can convert the float to a double on the PLC to get an integer, and then divide it back again in a macro on my screen, just thinking of ways to make my life a little less complicated.

Maybe you should use %MW and select data format to 32-bit Float to display in floating point.

M221_Weintek_01.jpg
 
That's what I was asking. If it works great, I know how to set data formats on the Weintek, but as it doesn't explicitly list %MF, only %MW and %MD I wasn't sure it would work.
 
That's what I was asking. If it works great, I know how to set data formats on the Weintek, but as it doesn't explicitly list %MF, only %MW and %MD I wasn't sure it would work.

I think it should work. Data in schneider PLC are in modbus address %M and %MW. %MF0 are means data from %MW0 and %MW1 in 32 bit float format when you use HMI to communicate with PLC if you use 32 bit float format in %MW0 when you write data it should be written in %MW0 anr %MW1 (%MF0).
 

Similar Topics

Hello, I need to access the bits from the fire system control panel through RS-485. So, I used Read Var block to read from the panel...
Replies
0
Views
189
Hi all, I've been trying to develop modbus rtu program between uv balasts and plc ı'have 6 slave balast.I am reading fault run voltages etc...
Replies
0
Views
1,196
Hello new user here seeking some guidance. I have been given the task of polling data from a modbus slave (Thermo 43i Analyzer) using RS-232...
Replies
2
Views
1,684
Halo Guys, I new to Schneider M221, I need your help. I have 1 project with M221 connected to 18 units of modbus devices. I can't use Modbus...
Replies
0
Views
1,941
Hi there, I’m in the process of using an iPad as an HMI to communicate with a Schneider Modicon M221 over ethernet. I’m using Libmod with a Swift...
Replies
1
Views
2,809
Back
Top Bottom