TM172 Modbus Register Bit Allocation

[POPE3909]

Hi Guys,

I have a question regarding Status Variables/ Modbus Registers creation in M172.

On ESME HVAC, under Status Variables, Starting from address 8960, when I create a new variable, it is a 16 bit holding register even if it is chosen as 'Boolean' Installer Type and 'BOOL' IEC type.
My understanding is that only the first bit of 16 bits is used as boolean and the rest are unused.

How can I use all the bits in the 16 bit holding register as boolean?
For example, currently under my status variables, I have registers, 10000, 10001, 10002, as AC1,2,3 faults respectively. Instead of doing that, I want to use different bits of register 10000 as respective AC faults, like 10000.1 > AC 1 fault
10000.2 > AC 2 fault
10000.3 > AC 3 fault etc.

I am pretty sure there should be a way to do it. Could you please give some directions on that? Thanks in advance.

[FedericoM · Accepted solution]

Hi,

assuming your status variable name is Var10000 you can define it as a WORD and write:

Var10000.0 := xAC1fault;

Var10000.1 := xAC2fault;

...

Var10000.15:= xAC16fault;

This notation is not supported by M171O, in this case (but also as an alternative) you can use bitToWord() function of the Basic Library

[POPE3909]

Thank you. Appreciate your prompt response.