Hello Guys,

i am using Siemens PLC for the first time. one of the PLC brand addressing of bits and registers M0-1900(bits) and registers(R0-R3999) but how it is distributed in Siemens? What i know is there is only one series in M0.0 where it can be represent as MB MW MD . Is there any other series or this is the only series "M"? Because i think these are very limited number of for memory.

Thanks for your response.

Kindly guide my any link where i can study about this data block. 

Dear zobi92

Also have a look at this link

https://program-plc.blogspot.com/2015/09/data-blocks-in-simatic-step-7-siemens.html

Regards

zobi92

Hello Guys,

i am using Siemens PLC for the first time. one of the PLC brand addressing of bits and registers M0-1900(bits) and registers(R0-R3999) but how it is distributed in Siemens? What i know is there is only one series in M0.0 where it can be represent as MB MW MD . Is there any other series or this is the only series "M"? Because i think these are very limited number of for memory.

 Please refer Programming with STEP 7 V5.4 manual, may help you.

Thank you everyone for your response.

One more question i will use DB for words variable and allocate M for only bits, is it ok?

or is there any standard?

Secondly are DB and M retentive memory?

Thank you for your response

Are they both retentive means on power loss do they store data?

Secondly if I have to display these DB variables on HMI can I?

Dear zobi92

Yes you can, just only add tags at screen and connect to the data block..

Have a look at this Link

Regards,