Writing bits from System Platform to KepServer

[Doron_Hassidim]

Hello PLCtalk community,
I force to 1 bits in System Platform that are read by KepServer, and for some reason other bits are going down to zero. It seems the problem persists even when KepServer is shut down. Can it be System Platform just writes words with only one bit up and all the others zero?

 

[parky]

What is your "System platform" ?
Kepserver is capable of reading or writing bits on most protocols & if it is not running then it must be your platform.
could you elaborate a little more.
One other thing when you say Kepserver is not running are you sure as it can also run as a service.

 

[ynpmoose]

Which driver are you using in Kepware? Are you writing true booleans, or writing to a bit of an integer, etc?

 

[Doron_Hassidim]

System Platform is my SCADA software. KepServer stands between it and the I/O itself, i.e., the PLCs

 

[Steve Bailey]

What model PLC?
What protocol?

I force to 1 bits in System Platform that are read by KepServer, and for some reason other bits are going down to zero.

I understand this to mean that from one of the screens in the System Platform you are trying to turn on a single bit in the PLC, but when you monitor the address of that bit in the PLC you see that other bits in adjacent addresses are also affected. Is that correct?

It seems the problem persists even when KepServer is shut down

How is the System Platform communicating with the PLC when KEPServer is shut down?

 

[Doron_Hassidim]

We are in development mode, so not connected directly to PLC, just to Kepserver and a gateway to test communication. I force in System Platform's object viewer attributes that are associated with Kepserver's iten references (so not in a screen even). When I force 1 to one attribute, other boolean 'adjacent' attributes (probably only in the same word - I'm not sure how the memory archetectute works there) are also affected, specifically they all go to 0 - as if there is some kind of masking that sends a word of 0000...1...0000 instead of a single boolean

 

[Steve Bailey]

Your hypothesis that the system can't write to a single bit may be accurate, but you'll need to be able to drill down to the details of the addressing to be able to verify it. I think you would be better served to use an actual PLC it your development.

 

[Ken Moore]

Different PLC's require different syntax to address bits (if possible)

Since you will not share your PLC make/model. It's difficult to help.

 

[Doron_Hassidim]

It seems we are able to solve the problem we have in Kepserver with the configuration seen on the picture (changing to Disable the feature "Holding Register Bits Write" in Property Editor / Settings).

It is unclear to me when I will want this to be Enable, and more than this why the default is Enable – it completely prevents communicating single bits that are located next to each other.
Are there any other configurations I might want to examine?