Reading certain bits from a 16-bit register.

[Sergelenbat]

Greetings.

Let me preface this by saying that I am entirely new to automation. Everything was going along fine until I ran into an old SEL connected by Modbus RTU over TCP/IP. I can pull the metering data just fine with MODNET. But the relay stores contact statuses as a single 16 bit with specific bits corresponding to different contacts. I have tried to change the driver to PwrModbus and configure the bitmask but I seem to failing entirely. Any help would be appreciated.

[olivier_vallee · Accepted solution]

Hi @Sergelenbat,

The PwrModbus is quite a complex driver, and is best configured using the Power SCADA Expert IDE and equipment tool with pre-defined templates for each device type.

Where would you like to use this bit extraction information? If on a page or in Cicode, you could simply use BITAND to extract the corresponding bit from the 16 bit integer.

E.g. to extract Bit 3 from Tag1, just use this (assuming Bit 0 is the first digital):

Tag1 BITAND 4

Hope this information helps.

Kind regards

Olivier