Combining Consecutive Modbus Registers to read FLOAT

2020-02-27T21:16:00.310000Z

%ML0 does not exist.
if the float is same as real in definition you only have to do a dword_to_real

Combining Consecutive Modbus Registers to read FLOAT

2020-02-27T21:15:58.879000Z

AT. Below are examples where the head address of the array is mapped to individual address for float variables.

HOLD_REG AT %MW0: ARRAY[0..20] OF WORD;

POS_X AT %ML0 : LREAL;
POS_Y AT %ML1 : LREAL;
POS_Z AT %ML2 : LREAL;
POS_S AT %ML3 : LREAL;

http://forum.codesys.com/viewtopic.php?f=2&t=5045

Combining Consecutive Modbus Registers to read FLOAT

2020-02-27T21:15:54.841000Z

You can try something like:

VAR
  awWords      : ARRAY[1..2] OF WORD;
  pReal : POINTER TO REAL;
  rReal : REAL;
END_VAR
awWords[1] := (* whatever code is needed to read the register *);
awWords[2] := (* whatever code is needed to read the register *);
pReal := ADR(awWords);
rReal := pReal^;

Combining Consecutive Modbus Registers to read FLOAT

2020-02-27T21:15:53.251000Z

Hi,

I am using a 750-842 FBC to communicate with several other devices on a Modbus TCP network setup. I have a 352 Remote I/O, 2 Power Monitors through a Gateway, and a Generator controller.

For some registers within the Power Monitors, The floating point value occupies 2 consecutive registers (i.e. 4002, 4003).

How can I combine these two so that I can read the value? Im using the Ethernet_Modbusmaster_TCP function block to retrieve data from each of these devices.

Thanks in advance,

Jason

Recent posts to Combining Consecutive Modbus Registers to read FLOAT

Combining Consecutive Modbus Registers to read FLOAT

Combining Consecutive Modbus Registers to read FLOAT

Combining Consecutive Modbus Registers to read FLOAT

Combining Consecutive Modbus Registers to read FLOAT